Next Article in Journal
Facile Doping of 2,2,2-Trifluoroethanol to Single-Walled Carbon Nanotubes Electrodes for Durable Perovskite Solar Cells
Previous Article in Journal
A Systematic Review of Heterogeneous Catalysis Applied to the Treatment of Pharmaceutical Wastewater: Operational Conditions and Statistical Analysis
 
 
Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
Journals
Photochem
Volume 4
Issue 3
10.3390/photochem4030018
photochem-logo
Submit to this Journal Review for this Journal Propose a Special Issue
► Article Menu

Article Menu

share Share announcement Help format_quote Cite question_answer Discuss in SciProfiles thumb_up
...
Endorse textsms
...
Comment
first_page
settings
Order Article Reprints
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:
Background:
Article

Synthesis of Metallic and Metal Oxide Nanoparticles Using Homopolymers as Solid Templates: Luminescent Properties of the Eu+3 Nanoparticle Products

by
María Ángeles Cortés
1,
Carlos Díaz
1,
Raquel de la Campa
2,
Alejandro Presa-Soto
2 and
María Luisa Valenzuela
3,*
1
Departamento de Química, Facultad de Química, Universidad de Chile, La Palmeras, 3425, Nuñoa, Casilla 653, Santiago 8330015, Chile
2
Departamento de Química Orgánica e Inorgánica (IUQOEM), Facultad de Química, Universidad de Oviedo, Julián Clavería s/n, 33006 Oviedo, Spain
3
Facultad de Ingeniería, Instituto de Ciencias Aplicadas, Universidad Autónoma de Chile, Av. El Llano Subercaseaux, 2801, Santiago 7500912, Chile
*
Author to whom correspondence should be addressed.
Photochem 2024, 4(3), 302-318; https://doi.org/10.3390/photochem4030018
Submission received: 17 April 2024 / Revised: 3 July 2024 / Accepted: 4 July 2024 / Published: 14 July 2024
Browse Figures
Versions Notes

Abstract

:
Starting from poly(4-vinylpyridine) ((P4VP)n), poly(2-vinylpyridine) ((P2VP)n), and [N=P(O2CH2CF3)]m-b-P2VP20 block copolymers, a series of metal-containing homopolymers, (P4VP)n⊕MXm, (P2VP)n⊕MXm, and [N=P(O2CH2CF3)]m-b-P2VP20]⊕MXm MXm = PtCl2, ZnCl2, and Eu(NO3)3, have been successfully prepared by using a direct and simple solution methodology. Solid-state pyrolysis of the prepared metal-containing polymeric precursors led to the formation of a variety of different metallic and metal oxide nanoparticles (Pt, ZnO, Eu2O3, and EuPO4) depending on the composition and nature of the polymeric template precursor. Thus, whereas Eu2O3 nanostructures were obtained from europium-containing homopolymers ((P4VP)n⊕MXm and (P2VP)n⊕MXm), EuPO4 nanostructures were achieved using phosphorus-containing block copolymer precursors, [N=P(O2CH2CF3)]m-b-P2VP20]⊕MXm with MXm = Eu(NO3)3. Importantly, and although both Eu2O3 and EuPO4 nanostructures exhibited a strong luminescence emission, these were strongly influenced by the nature and composition of the macromolecular metal-containing polymer template. Thus, for P2VP europium-containing homopolymers ((P4VP)n⊕MXm and (P2VP)n⊕MXm), the highest emission intensity corresponded to the lowest-molecular-weight homopolymer template, [P4VP(Eu(NO3)3]6000, whereas the opposite behavior was observed when block copolymer precursors, [N=P(O2CH2CF3)]m-b-P2VP20]⊕MXm MXm= Eu(NO3)3, were used (highest emission intensity corresponded to [N=P(O2CH2CF3)]100-b-[P2VP(Eu(NO3)3)x]20). The intensity ratio of the emission transitions: 5D0 → 7F2/5D0 → 7F1, suggested a different symmetry around the Eu3+ ions depending on the nature of the polymeric precursor, which also influenced the sizes of the prepared Pt°, ZnO, Eu2O3, and EuPO4 nanostructures.

Graphical Abstract

1. Introduction

Polyphosphazenes, with the general formula [N=P(R2)]n (Figure 1), are an important class of inorganic polymers with relevant applications in material science [1]. Since their first synthesis as high-molecular-weight and well-defined polymers in 1965 by Allcock and Kugel [2], the chemistry of these materials has experienced extraordinary growth due to the excellent properties (e.g., biodegradability [3,4], high fire resistance [5], and elasticity [6]) and the variety of potential and real applications [7] of those inorganic macromolecules, among other things. Currently, polyphosphazenes with a wide variety of different chain architectures are known (see Figure 1) due to the extraordinary synthetic versatility ([N=PCl2]n) of the starting material, which allows a direct substitution of the chlorine atoms using an appropriate nucleophile [8,9,10,11,12]. Moreover, in 1995, the groups of Allcock and Manners developed the living cationic chain-growth condensation polymerization of Cl3P=N-SiMe3 promoted by PCl5 [13]. This polymerization provides a molecular weight control of poly(dichloro)phosphazene by simply altering the Cl3P=N-SiMe3/PCl5 ratio. It is well known that this living polymerization provides access to polyphosphazene block copolymers (see Figure 1) via a sequential monomer addition [14].
Recently, polyphosphazenes have been exploited in nanoscience to stabilize metallic nanoparticles (Au and Ag, among others) and as a solid-state template for the synthesis of a wide variety of metallic and metal oxide nanoparticles [15]. The great stabilization ability of polyphosphazene materials is mainly due to (i) the presence of coordinative moieties at the side groups of the main chain (i.e., R1-R4 side groups in Figure 1) and (ii) the presence of N atom in the main chain. Although it is not a very good ligand, this provides an additional coordinative site that can eventually prevent the agglomeration of the nanoparticles. In this regard, polyphosphazenes can easily form a macromolecular metal complex type, such as MXn·Polyphosphazene, which, after thermal treatment in the presence of oxidizing atmosphere (air), leads to the corresponding metal phosphate nanoparticles (MxPxOy) [16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41]. On the other hand, using organic polymers based on poly(4-vinylpyridine) (P4VP) chains, such as PSP-co-P4VP (PS = polystyrene), or chitosan, the pure metal oxide MxOy nanoparticles were successfully achieved [42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59]. Thus, aiming to evaluate the combined effect of both polyphosphazenes and poly(vinylpiridine) materials in the formation of metallic nanoparticles, in this report, we describe the synthesis of metallic phosphate nanoparticles of europium using polyphosphazene-b-poly(2-vinylpiridine) (PP-b-P2VP) block copolymers as a solid-state template. Also, as model reactions, we describe the formation of pure Pt nanoparticles and metal oxide nanoparticles (ZnO and Eu2O3) by using P2VP and P4VP homopolymers as solid-state templates.
Considering the results of obtaining nanoparticles using macromolecular complexes as precursors with polyphosphazenes as polymers [16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41] and, furthermore, obtaining nanoparticles using chitosan and PSP-co-P4VP polymers [42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59], we observed a possible dependence of the composition of the nanoparticles on the nature of the polymer, acting as a mold in the solid state. If, instead, the polymer matrix of the precursor is made up of polyphosphazenes, the formation of nanoparticles of metal phosphates and pyrophosphates is usual [20,24,25,26,28,29,31,35,36,42], while when the macromolecular precursor is an organic polymer that does not contain phosphorus in its chain, nanoparticles of pure metal oxides are normally obtained [47,48,49,51,53,54,55,57]. Therefore, the main objective of this work was to use a polymer that contains a phosphazenic unit, such as [N=P(O2CH2CF3)], and an organic unit, such as P2VP, in its chain, to check whether the nanoparticles obtained using this copolymer as a precursor would produce nanoparticles of metal phosphates, only pure metal oxides, or a mixture of phosphates and metal oxides. These results could advance the knowledge of the formation mechanism in the solid state, using macromolecular complexes as precursors and polymers as templates.

2. Materials and Methods

2.1. Materials

For better clarity, ease, and understanding of the text, we have numbered the precursors as follows: poly(4-vinylpyridine) ((P4VP)n; Mw = 6000 (1a) and 160,000 (1b)), poly(2-vinylpyridine) Mw = 37,500 (1c), and [N=P(O2CH2CF3)]m-b-P2VP20 block copolymers (m = 20 (2a), 60 (2b), and 100 (2c)), the series of metal-containing homopolymers as: [P4VP(PtCl2)x]6000 (1a-Pt), [P4VP(PtCl2)x]160000 (1b-Pt), [P2VP(PtCl2)x]37500 (1c-Pt), [P4VP(ZnCl2)x]6000 (1a-Zn), [P4VP(ZnCl2)n]160000 (1b-Zn), [P2VP(ZnCl2)n]37500 (1c-Zn), [P4VP(Eu(NO3)3]6000 (1a-Eu), [P4VP(Eu(NO3)3]160000 (1b-Eu), and [P2VP(Eu(NO3)3]37500 (1c-Eu), and block copolymers as: [N=P(O2CH2CF3)]20-b-[P2VP(Eu(NO3)3)x]20 (2a-Eu), [N=P(O2CH2CF3)]60-b-[P2VP(Eu(NO3)3)x]20 (2b-Eu), and [N=P(O2CH2CF3)]100-b-[P2VP(Eu(NO3)3)x]20 (2c-Eu).
The [N=P(O2CH2CF3)]m-b-P2VP20 block copolymers (m = 20 (2a), 60 (2b), and 100 (2c)) were prepared by following the previously described literature procedures [52]. PtCl2, ZnCl2, Eu(NO3), poly(4-vinylpyridine), and poly(2-vinylpyridine) (Aldrich) were used as-received without any additional purification step.

2.2. Synthesis of Macromolecular Metal Complex of Type MXn-Polymer

In a typical procedure, an equimolar amount of the corresponding polymer and the desired metallic precursor was placed in a Schlenk tube and 20 mL of dichloromethane was added. The heterogeneous mixture was stirred at room temperature for 8 days. The solid obtained was filtered and washed with dichloromethane. The obtained solid residue was dried under vacuum for 3 h. For further experimental details, see Table S1 in the Electronic Supplementary Materials. Next, the obtained solids were placed into a box furnace (lab tech) and treated under a pyrolysis program. The oven remained at 200 °C for 10 min, then its temperature was raised to 800 °C in 50 min, to finally remain at this temperature for 4 h, in the air atmosphere. The pyrolytic residues were characterized by (i) X-ray diffraction (XRD; Siemens D-5000 diffractometer with θ–2θ geometry), whereby XRD data were collected using Cu-Kα radiation (40 kV, 30 mA), (ii) elemental microanalysis (performed via energy-dispersive X-ray analysis using a NORAN Instrument micro-probe attached to the scanning electron microscope), (iii) SEM analysis (images were acquired with a Philips EM 300 scanning electron microscope), (iv) energy-dispersive X-ray analysis (EDAX; NORAN Instrument micro-probe attached to a JEOL 5410 scanning electron microscope), and (v) high-resolution transmission electron microscopy (HR-TEM; JEOL 2000FX TEM microscope at 200 kV, Tokyo, Japan) to characterize the average particle size, distribution, and elemental and crystal composition. The average particle size was calculated using the Digital Micrograph software (Windows 2000 Professional).

3. Results and Discussions

3.1. Macromolecular Complexes (1a-Pt), (1a-Zn), (1a-Eu), (1b-Pt), (1b-Zn), (1b-Eu), (1c-Pt), (1c-Zn), and (1c-Eu)

Macromolecular complexes were prepared by coordination of the corresponding metallic salts with the respective polymer. Experimental details are provided in the experimental section and the Supplementary Materials. The solid obtained was completely insoluble in all conventional organic solvents, and characterization was performed by means of FT-IR spectroscopy and TG/DTA analysis. FT-IR spectra (see the Supplementary Materials) showed the expected shifting of the stretching bands related to the metal-coordinated pyridine moiety with respect to those of the free pyridine groups [18,19]. Thus, in all of the synthesized macromolecular complexes, (1a-Pt), (1a-Zn), (1a-Eu), (1b-Pt), (1b-Zn), (1b-Eu), (1c-Pt), (1c-Zn), and (1c-Eu), a lower frequency shift of ca. 5 cm−1 was observed for the metal-coordinated pyridine side groups.
Comparative TG/DTA analyses of Zn-based macromolecular complexes of (1a) and (1a-Zn) and the corresponding non-coordinated (1a) chains clearly showed two main decomposition steps, one corresponding to non-coordinated pyridine groups (390–410 °C) [55] and the other, at 430–650 °C, corresponding to (1a-Zn) moieties (Figure 2). Similar behavior was observed in all other synthesized macromolecular complexes. The metallic coordination degrees of the polymeric materials were calculated on the basis of the amount (%) of final residue, ZnO, obtained in each TG/DTA analysis [54,55]. Thus, coordination degrees ranging from >99% to 47% were observed depending on the employed polymeric material and metallic source (analyses can be performed for other macromolecular complexes).
Thus, by comparing the residue assigned to the ZnO, considering a 100% coordination with the obtained residue, a coordination degree could be estimated [22,23]. Values were in the range of 47–100% (see the Supplementary Materials).

3.2. Pyrolysis of the Macromolecular Metal, (1a-Pt), (1a-Zn), (1a-Eu), (1b-Pt), (1b-Zn), (1b-Eu), (1c-Pt), (1c-Zn), and (1c-Eu), to Nanostructured Pt, ZnO, and Eu2O3

The pyrolysis of macromolecular metal complexes, MXn·polymer, was carried out at 800 °C under air atmosphere, leading to the corresponding Pt, ZnO, and Eu2O3 nanostructured materials. The crystallographic phase of the prepared nanostructured materials were studied by power X-ray diffraction (Figure 3). Thus, diffractograms of PtCl2-based materials, (1a-Pt), (1b-Pt), and (1c-Pt), showed diffraction peaks corresponding to planes (111), (200), (220), and (101), characteristic of cubic Pt [52].
On the other hand, diffractograms of ZnCl2-based materials, (1a-Zn), (1b-Zn), and (1c-Zn), showed diffractions corresponding with planes (101), (002), (100), (102), (110), and (200), characteristic of ZnO (Figure 4) [48].
Similarly, diffractograms of Eu(NO3)3-based materials, (1a-Eu), (1b-Eu), and (1c-Eu), showed diffractions corresponding with planes (222), (400), (440), and (662), characteristic of pure phases of Eu2O3 (Figure 5) [50].
The structures of the synthesized materials were also investigated by SEM and EDS. Thus, SEM images of PtCl2-based materials ((1a-Pt), (1b-Pt), and (1c-Pt), Figure 6) after pyrolysis showed the presence of dense aggregated grains. The high aggregation created the typical metal-foam-type morphology [32]. EDS analysis supported the presence of Pt° as the sole element (Figure 6d).
SEM images of the as-synthesized ZnO materials showed (Figure 7) the presence of a cuboidal-like nanostructure. These nanostructures were densely packed, exhibiting similar structures as those observed in previous works of the group [48]. Again, EDS analysis supported the presence of pure phases of ZnO.

3.2.1. EDS Analysis of (1c-Zn)

The SEM images of the as-prepared Eu2O3 material (Figure 8) showed cotton-like morphologies, with the EDS analysis being in accordance with the presence of Eu2O3.

3.2.2. EDS Analysis of (1c-Eu)

As-prepared nanostructured materials were also investigated using TEM. Thus, TEM analysis of nanostructured Pt prepared by pyrolysis of the macromolecular precursors (a) (1a-Pt), (c) (1b-Pt), and (d) (1c-Pt) showed the presence of platinum nanoparticles with relatively monodisperse sizes (62 nm, 47 nm, and 95 nm, respectively, see Figure 9). According to the electron diffraction images, the Pt sample from the (1c-Pt) precursor appeared to be more crystalline than that from the 1a-Pt precursor.
TEM images of nanostructured ZnO prepared by pyrolysis of the macromolecular precursors (a) (1a-Zn), (b) (1b-Zn), and (c) (1c-Zn) showed the presence of rather monodisperse nanoparticles, with average sizes of 70 nm, 60 nm, and 80 nm (see Figure 10). According to the electron diffraction images, the ZnO sample from the (1a) precursor appeared to be more crystalline than that from the (1b) and (1c) precursors.
TEM images of nanostructured Eu2O3 obtained by pyrolysis of the macromolecular precursors (a) (1a-Eu), (b) (1b-Eu), and (c) (1c-Eu) showed the presence of concatenated nanostructures with particle sizes ranging from 50 to 60 nm (see Figure 11). As a general trend, we observed smaller particle sizes when high-molecular-weight precursors were employed, which agrees with the higher surfactant ability of these solid templates during grain growing. According to the electron diffraction images, the Eu2O3 samples from all the precursors appeared to be of similar crystallinity.

3.3. Pyrolysis of Polyphosphazene-Based Macromolecular Metal Complexes ([N=P(O2CH2CF3)]20-b-[P2VP(Eu(NO3)3)x]20 (2a-Eu), [N=P(O2CH2CF3)]60-b-[P2VP(Eu(NO3)3)x]20 (2b-Eu), and [N=P(O2CH2CF3)]100-b-[P2VP(Eu(NO3)3)x]20 (2c-Eu)) to EuPO4

The pyrolysis of the polyphosphazene block copolymer metal complexes, (2a-Eu), (2b-Eu), and (2c-Eu), using the previously described experimental conditions, led to the formation of nanostructured EuPO4. The synthesis of pure phases of monoclinic EuPO4 (diffraction planes (110), (101), (200), (002), (120), (−221), (−311), and (−041)) [60] was confirmed by X-ray diffraction analysis (Figure 12).
SEM images of the as-obtained EuPO4 showed a typical foam-like morphology for all the examined nanostructured materials (Figure 13) [61,62]. Importantly, EDS analysis exhibited the presence of Eu, P, and O, which agreed with the formation of pure EuPO4 phases (Figure 13).
As-prepared EuPO4 nanostructures were also examined by TEM. Thus, TEM images (Figure 14) showed well-defined nanoparticles with average sizes ranging from 25 to 40 nm. Importantly, interplanar distances of 0.499 nm and 0.503 nm, corresponding to the plane (−101) of monoclinic EuPO4, were clearly observed for samples resulting from the pyrolysis of (2a-Eu) and (2b-Eu) precursors. The electron diffraction patterns of the EuPO4 nanostructures prepared here demonstrated their crystalline nature.
A possible formation mechanism of the nanoparticles can be proposed on the basis of previous studies on solid-state formation of nanostructured metal oxide materials using the same synthetic approach [38,45,58] (see the Supplementary Materials). According to these studies, the first step of heating the samples involves the formation of a 3D network to produce a thermally stable matrix. This step is crucial because it offsets the sublimation. The first heating step could involve a crosslinking of the polyphosphazene-b-poly(2-vinylpiridine), poly(4-vinylpyridine), or poly(2-vinylpyridine) polymers, yielding a 3D matrix containing the PtCl2, ZnCl2, and Eu(NO3)3 metals joined to the polymeric chain. The next stage could be the beginning of the organic carbonization, producing holes where the nanoparticles begin to nucleate. As it was confirmed in earlier studies [29], the formation of Pt, ZnO, Eu2O3, and EuPO4 nanoparticles could occur over a layered graphitic carbon host, which is lost near the final annealing temperature, i.e., 800 °C.

3.4. Optical Properties

The bandgap values, Eg, of as-prepared ZnO ranged from 3.23 to 4.24 eV depending on the macromolecular precursor used during the pyrolysis treatment (see the Tauc plots and table of tabulated values in the Supplementary Materials). As a result of the smaller nanoparticle sizes obtained by using these macromolecular precursors as solid-state templates, in comparison with those of other published solid templates [48], the obtained bandgap values were slightly higher than those expected for nanostructured ZnO materi-als [62]. On the other hand, the bandgap values of as-prepared Eu2O3 oxides were in the range of 4.34 and 4.52 eV, which is consistent with those reported in the literature for these materials, suggesting an insulator behavior [63].

3.5. Study of the Luminescent Properties of Nanostructured Eu2O3 and EuPO4 Materials Prepared by Pyrolysis of the Macromolecular Metal Precursors (1a-Eu), (1b-Eu), and (1c-Eu) and of EuPO4 from (2a-Eu), (2b-Eu), and (2c-Eu)

As expected, the as-prepared nanostructured Eu2O3 and EuPO4 exhibited luminescence properties due to the presence of the Eu3+ ions [64,65,66,67,68]. Thus, the emission spectra (λexc = 395 nm) of Eu2O3 synthesized from precursors (1a-Eu), (1b-Eu), and (1c-Eu) (Figure 15) showed the characteristic pattern of the lanthanide oxide series. It is important to note that the intensity of the emission is affected by the symmetry of the Eu3+ environment. Thus, the 5D0→7F1 lines originated from the magnetic dipole transition, while the 5D0→7F2 lines originated from the electric dipole transitions [66]. The electric dipole transition is permitted only when Eu3+ ions occupy sites with no inversion center, and it is sensitive to local symmetry. This fact induces the relatively strong 5D0 → 7F2 transition. Interestingly, the photoluminescence intensity of the electric–dipole transition of 5D0 → 7F2 was stronger than the magnetic dipole transition of 5D0 → 7F1 when P4VP macromolecular metallic precursors were employed as a solid template (note the opposite behavior when P2VP precursors were used, see Figure 15). It is well known that the 5D0 → 7F2 transition is more sensitive to symmetry than the 5D0 → 7F1 transition. The symmetry around the Eu3+ ions in as-synthesized Eu2O3 was higher in materials prepared from the pyrolysis of P2VP-based metallic precursors than that of the materials prepared by pyrolysis of P4VP-based templates. These results clearly pointed out the importance of the chosen solid template over the symmetry of the as-obtained Eu2O3 nanomaterials.
The luminescence emission spectra (λexc = 395 nm) of nanostructured EuPO4 synthesized by pyrolysis of (2a-Eu), (2b-Eu), and (2c-Eu) showed, for all the synthesized materials (Figure 15), a weaker 5D0 → 7F1 transition and stronger 5D0→7F2, which is indicative of a low-symmetry environment around the Eu3+ ions [66,67,68].
Table 1 presents a summary of all the relevant data (particle sizes, morphology, and optical properties) of the nanostructured Pt, ZnO, Eu2O3, and Eu(NO3)3 prepared by using different macromolecular solid-state precursors.
The analysis of the experimental data collected in Table 1 led to the conclusion that larger nanoparticles were created by using solid polymeric templates of lower-molecular-weight distributions. On the other hand, it seems that the as-obtained morphologies of the nanostructured materials were not significantly influenced by the nature of the macromolecular solid template.

4. Conclusions

The solid-state pyrolysis of the metal-polymer precursors ((P4VP)n⊕MXm and (P2VP)n⊕MXm, M = PtCl2, ZnCl2, and Eu(NO3)3) led to Pt, ZnO, and Eu2O3 nanostructures, respectively. On the other hand, EuPO4 nanostructured material can be obtained by using polyphosphazene block copolymer metal complexes as a solid-state template during the pyrolysis treatment of (2a-Eu), (2b-Eu), and (2c-Eu). These results clearly pointed out that the presence of phosphorous atoms in the polyphosphazene block controlled the formation of nanostructured EuPO4 materials during pyrolysis, even when the Eu(NO3)3 was selectively coordinated in the P2VP block. By comparing the nature, morphology, size, and properties of the nanostructured Pt, ZnO, Eu2O3, and EuPO4 materials, it was clear that the length of the polymeric chains controlled the size of the obtained nanoparticles. Thus, a smaller particle size was obtained by using longer polymeric chains. Analysis of the luminescent properties of the Eu3+-containing nanostructured materials revealed that the symmetry of Eu3+ ions was strongly affected by the nature of the polymeric solid precursors. The herein described results represent a step forward in understanding the experimental parameters controlling the formation of nanoparticles in solid state and constitute a new advance toward the elucidation of the mechanisms involved in the formation of these nanoparticles in the solid state.

Supplementary Materials

The following supporting information can be downloaded at: https://www.mdpi.com/article/10.3390/photochem4030018/s1, Table S1: Experimental details for the synthesis of the precursors (Polymer) MCl2 (M= Pt and Zn) and (Polymer) Eu(NO3)3; Table S2: FT-IR data of polymers (P4VP, P2VP and [N=P(O2CH2CF3)2] n -b-[P2VP] m and metallic macromolecular precursors MX2·polymer and (MCl2; M = Pt or Zn) and Eu(NO3)3·polymers; Table S3: Metal coordination degree calculated by TGA/DTA curves; Figure S1: Band Gap values for ZnO and Eu2O3 calculated by using the Tauc plots. Nanostructured oxides were prepared by pyrolysis of the precursores 1a-Eu, 1b.Eu, 1c-Eu and 1a -Zn, 1b.Zn, 1cZn; Table S4: Band gap values for ZnO and Eu2O3 materials prepared by pyrolysis of the precursors 1a -Zn, 1b.Zn, 1c-Zn and 1a -Eu, 1b.Eu, 1c-Eu; Table S5: X-Ray Assignment for Eu2O3 Figure S2: Mechanism Formation.

Author Contributions

Conceptualization, M.L.V.; Methodology, M.Á.C. and R.d.l.C.; Validation, C.D. and A.P.-S.; Formal analysis, A.P.-S. and M.L.V.; Investigation, M.Á.C.; Writing—original draft, C.D.; Writing—review & editing, M.L.V.; Supervision, C.D., R.d.l.C. and A.P.-S. All authors have read and agreed to the published version of the manuscript.

Funding

This research was funded by the research residency support grant from the office of the Vice-Rector for Research and Postgraduate Studies in 2023, Universidad Autónoma de Chile.

Data Availability Statement

The data are contained within this article.

Acknowledgments

We thank T. Staedler and T. Guo (Institute of Materials Engineering, University of Siegen) for kindly providing the setup for the AFM measurements. We also thank M. Killian and T. Kowald (Chemistry and Structure of Novel Materials, University of Siegen) for recording the thin-film X-ray diffraction data.

Conflicts of Interest

The authors declare no conflicts of interest.

References

  1. Allcock, H.R. Recent developments in polyphosphazene materials science. Curr. Opin. Solid State Mater. Sci. 2006, 10, 231–240. [Google Scholar] [CrossRef]
  2. Allcock, H.R.; Kugel, R.L. Synthesis of high polymeric alkoxy- and aryloxy-phosphonitriles. J. Am. Chem. Soc. 1965, 87, 4216–4217. [Google Scholar] [CrossRef]
  3. Linhardt, A.; König, M.; Schöfberger, W.; Brüggemann, O.; Andrianov, A.K.; Teasdale, I. Biodegradable Polyphosphazene Based Peptide-Polymer Hybrids. Polymers 2016, 8, 161. [Google Scholar] [CrossRef] [PubMed]
  4. Weidel, A.L.; Krogman, N.R.; Nguyen, N.Q.; Nair, L.S.; Laurencin, C.T.; Allcock, H.R. Polyphosphazenes That Contain Dipeptide Side Groups: Synthesis, Characterization, and Sensitivity to Hydrolysis. Macromolecules 2009, 42, 636–639. [Google Scholar]
  5. Zhou, X.; Qiu, S.; Mu, X.; Zhou, M.; Cai, W.; Song, L.; Xing, W.; Hu, Y. Polyphosphazenes-based flame retardants: A review. Compos. Part B Eng. 2020, 202, 108397. [Google Scholar] [CrossRef]
  6. Allcock, H.R.; Smith, D.E.; Kim, Y.B.; Fitzgerald, J.J. Poly(organophosphazenes) Containing Allyl Side Groups: Cross-Linking and Modification by hydrosilylation. Macromolecules 1994, 27, 5207–5215. [Google Scholar] [CrossRef]
  7. Akram, M.; Wang, L.; Yu, H.; Amer, W.A.; Khalid, H.; Abbasi, N.M.; Chen, Y.; Saleem, M.; Tong, R. Polyphophazenes as anti-cancer drug carriers: From synthesis to application. Prog. Polym. Sci. 2014, 39, 1987–2009. [Google Scholar] [CrossRef]
  8. Allcock, H.R.; Chen, C. Polyphosphazenes: Phosphorus in inorganic−organic polymers. J. Org. Chem. 2020, 85, 14286–14297. [Google Scholar] [CrossRef] [PubMed]
  9. Rothemund, S.; Teasdale, I. Preparation of polyphosphazenes: A tutorial review. Chem. Soc. Rev. 2016, 45, 5200–5215. [Google Scholar] [CrossRef]
  10. Allcock, H.R. The expanding field of polyphosphazene high polymers. Dalton Trans. 2016, 45, 1856–1862. [Google Scholar] [CrossRef]
  11. Gleria, M.; De Jaeger, R. (Eds.) Synthesis Characterization and Applications of Phosphazenes; Nova Science: Hauppauge, NY, USA, 2014; Volume 3, p. 83. [Google Scholar]
  12. Allcock, H.R. A Perspective of Polyphosphazene Research. J. Inorg. Organomet. Polym. Mater. 2006, 16, 277–294. [Google Scholar] [CrossRef]
  13. Honeyman, C.H.; Manners, I.; Morrissey, C.T.; Allcock, H.R. Ambient Temperature Synthesis of Poly(dichlorophosphazene) with Molecular Weight Control. J. Am. Chem. Soc. 1995, 117, 7035–7036. [Google Scholar] [CrossRef]
  14. Carriedo, G.A.; De la Campa, R.; Presa Soto, A. Polyphosphazenes—Synthetically Versatile Block Copolymers (“Multi-Tool”) for Self-Assembly. Eur. J. Inorg. Chem. 2018, 2018, 2484–2499. [Google Scholar] [CrossRef]
  15. Díaz, C.; Valenzuela, M.L. Metallic Nanostructures Using Oligo and Polyphosphazenes as Template or Stabilizer in Solid State. In Encyclopedia of Nanoscience and Nanotechnology; Nalwa, H.S., Ed.; American Scientific Publishers: Valencia, CA, USA, 2010; Chapter 16. [Google Scholar]
  16. Díaz, C.; Castillo, P.; Valenzuela, M.L. Thermolytic Transformations of Organometallic Polymer Containing the Cr(CO)5 Precursor into Nanostructured Chromium Oxide. J. Clust. Sci. 2005, 16, 515–522. [Google Scholar] [CrossRef]
  17. Díaz, C.; Valenzuela, M.L. Synthesis of Nanostructured Materials by a New Solid State Pyrolysis Organometallic Method. J. Chil. Chem. Soc. 2005, 50, 417–419. [Google Scholar] [CrossRef]
  18. Díaz, C.; Valenzuela, M.L. Small Molecules and High Polymeric Phosphazenes Containing Oxypyridine Side Groups and Their Organometallic Derivatives: Useful Precursors to Nanostructured Materials. Macromolecules 2006, 39, 103–111. [Google Scholar] [CrossRef]
  19. Carriedo, G.; Garcia Alonso, F.J.; Díaz, C.; Valenzuela, M.L. Synthesis and thermal decarbonylation of W(CO)5 complexes supported by nitrile, pyridine, or phosphine ligands to poly-spirophosphazene random copolymers carrying O-C6H5CO2Pr groups. Polyhedron 2006, 25, 105–112. [Google Scholar] [CrossRef]
  20. Díaz, C.; Valenzuela, M.L. Photoluminiscent Manganese nanoparticles from solid state Polyphosphazenes organometallic derivatives. J. Inorg. Organomet. Polym. 2006, 16, 123–128. [Google Scholar] [CrossRef]
  21. Díaz, C.; Valenzuela, M.L.; Carriedo, G.; Garcia Alonso, F.J.; Presa-Soto, A. Neutral AuCl complexes supported in linear high molecular weight, poly-spirophosphazene-phosphine copolymer and its conversion to nanostructured gold materials. Polym. Bull. 2006, 57, 913–920. [Google Scholar] [CrossRef]
  22. Díaz, C.; Valenzuela, M.L. Organometallic Derivatives of Polyphosphazenes as Precursors for Metallic Nanostructured Materials. J. Inorg. Organomet. Polym. 2006, 16, 419–435. [Google Scholar] [CrossRef]
  23. Díaz, C.; Valenzuela, M.L.; Spodine, E.; Moreno, Y.; Peña, O. A Cyclic and Polymeric Phosphazene as Solid State Template for the Formation of RuO2 Nanoparticles. J. Clust. Sci. 2007, 18, 831–844. [Google Scholar] [CrossRef]
  24. Díaz, C.; Valenzuela, M.L.; Yutronic, N. Polyphosphazenes as Solid Templates for the Formation of Monometallic and Bimetallic Nanostructures. J. Inorg. Organomet. Polym. 2007, 17, 577–582. [Google Scholar] [CrossRef]
  25. Díaz, C.; Valenzuela, M.L.; Jimenez, J.; Laguna, A. Microsize and Nanosize BPO4 from Pyrolysis of a Carborane Substituted Polyphosphazene. J. Inorg. Organomet. Polym. 2006, 16, 211–218. [Google Scholar] [CrossRef]
  26. Carriedo, G.; Díaz, C.; Valenzuela, M.L.; Ushak, S. Synthesis and pyrolysis of silicon and tin containing poly(2,2′-dioxy-1,1′-biphenoxy-phosphazenes). Eur. Polym. J. 2008, 44, 686–693. [Google Scholar] [CrossRef]
  27. Díaz, C.; Valenzuela, M.L.; Ushak, S. Synthesis and characterization of N3P3(O2C12H8)2(OC6H4Si(CH3)3)(OC6H4Br) and its conversion to nanostructured Si materials. J. Clust. Sci. 2008, 19, 471–479. [Google Scholar] [CrossRef]
  28. Díaz, C.; Valenzuela, M.L.; Bravo, D.; Lavayen, V.; O’Dwyer, C. Synthesis and Characterization of Cyclotriphosphazenes Containing Silicon as Single Solid-State Precursors for the Formation of Silicon/Phosphorus Nanostructured Materials. Inorg. Chem. 2008, 47, 11561–11569. [Google Scholar] [CrossRef]
  29. Díaz, C.; Valenzuela, M.L.; Ushak, S.; Lavayen, V.; O’Dwyer, C. Nanostructured Silicon containing materials derived from solid state pyrolysis of sililated polyphosphazene derivatives. J. Nanosci. Nanotechnol. 2009, 9, 1825–1831. [Google Scholar] [CrossRef]
  30. Díaz, C.; Valenzuela, M.L.; Ushak, S.; Zuñiga, L.; O’Dwyer, C. Organometallic Derivatives of Cyclotriphosphazenes as precursors of Nanostructured Metallic Materials: A new solid-state method. J. Inorg. Organomet. Polym. 2009, 19, 507–520. [Google Scholar] [CrossRef]
  31. Díaz, C.; Valenzuela, M.L.; Carriedo, G. Polymer and Oligomer Phosphazene Cymantrene derivatives as solid-state precursors of nanostructured manganese pyrophosphate. Polym. Bull. 2009, 63, 829–835. [Google Scholar] [CrossRef]
  32. Jiménez, J.; Laguna, A.; Sanz, J.A.; Díaz, C.; Valenzuela, M.L.; Jones, P.G. Metallocyclo-and Polyphosphazenes Containing Gold or Silver: Thermolytic Transformations into Nanostructured Materials. Chem. Eur. J. 2009, 15, 13509–13520. [Google Scholar] [CrossRef]
  33. Díaz, C.; Valenzuela, M.L.; Laguna, A.; Lavayen, V.; Jimenez, J.; Power, L.; O’Dwyer, C. Metallophosphazene Precursors Routes to the Solid-State Deposition of Metallic and Dielectric Microstructures and Nanostructures on Si and SiO2. Langmuir 2010, 26, 10223–10233. [Google Scholar] [CrossRef]
  34. Díaz, C.; Lavayen, V.; O’Dwyer, C. Single-Crystal Micro/Nanostructures and Thin Films of Lamellar Molybdenum Oxide by Solid-State Pyrolysis of Organometallic Derivatives of a Cyclotriphosphazene. J. Solid-State Chem. 2010, 20, 1595–1603. [Google Scholar] [CrossRef]
  35. Díaz, C.; Valenzuela, M.L.; Bravo, D.; Dickinson, C.; O’Dwyer, C. Solid-State Synthesis of Embedded Single-Crystal Oxide and Phosphate Nanoparticles and In-Situ Crystallization. J. Colloid Interface Sci. 2011, 362, 21–32. [Google Scholar] [CrossRef] [PubMed]
  36. Díaz, C.; Valenzuela, M.L.; Villalobos, V.; Yutronic, N.; Barrera, G. Nanostructured VOx/VO(PO4)n. Using Solid-State Vanadium Containing Phosphazene Precursors: A Useful Potential Bi-Catalyst System. J. Clust. Sci. 2011, 22, 693–704. [Google Scholar] [CrossRef]
  37. Díaz, C.; Carriedo, G.A.; Valenzuela, M.L.; Zuñiga, L.; O’Dwyer, C. Polymer/Trimer/Metal Complex Mixtures as Precursors of Gold Nanoparticles: Tuning the Morphology in the Solid-State. J. Inorg. Organomet. Polym. Mater. 2012, 22, 447–454. [Google Scholar]
  38. Díaz, C.; Valenzuela, M.L.; Lavayen, V.; O’Dwyer, C. Layered Graphitic Carbon Host Formation during Liquid-free Solid Stat Growth of Metal Pyrophosphates. Inorg. Chem. 2012, 51, 6228–6236. [Google Scholar] [CrossRef]
  39. Díaz, C.; Valenzuela, M.L.; Garrido, D.; Aguirre, P. Sol-Gel Incorporation of Organometallic Compounds into Silica. Useful Precursors to Metallic Nanostructured Materials. J. Chil. Chem. Soc. 2012, 57, 1155–1160. [Google Scholar] [CrossRef]
  40. Díaz, C.; Valenzuela, M.L.; Garrido, D.; Riquelme, J.; Díaz, R. The inclusion of Organometallic Derivatives of Cyclotriphosphazenes inside SiO2 Matrix and Their Conversion to Nanostructured Metal-oxides and Phosphates. J. Inorg. Organomet. Polym. Mater. 2012, 22, 1101–1112. [Google Scholar] [CrossRef]
  41. Díaz, C.; Valenzuela, M.L.; Garrido, D.; Zuñiga, L.; O’Dwyer, C. Solid State Pathways to Complex Shape Evolution and Tunable Porosity during Metallic Crystal Growth. Sci. Rep. 2013, 3, 2642. [Google Scholar]
  42. Díaz, C.; Valenzuela, M.L.; Lavayen, V.; Mendoza, K.; Peña, O.; O’Dwyer, C. Nanostructured copper oxides and phosphates from a new solid-state route. Inorganica Chim. Acta 2011, 377, 5–11. [Google Scholar] [CrossRef]
  43. Díaz, C.; Barrera, G.; Segovia, M.; Valenzuela, M.L.; Osiak, M.; O’Dwyer, C. Crystallizing Vanadium Pentoxide Nanostructures in the Solid State using Modified Block Co-Polymer and Chitosan Complexes. J. Nanomater. 2015, 2015, 105157. [Google Scholar] [CrossRef]
  44. Díaz, C.; Barrera, G.; Segovia, M.; Valenzuela, M.L.; Osiak, M.; O’Dwyer, C. Solvent-less method for efficient photocatalytic α-Fe2O3 nanoparticles for using macromolecular polymeric precursors. New J. Chem. 2016, 40, 6768–6776. [Google Scholar] [CrossRef]
  45. Díaz, C.; Valenzuela, M.L.; Laguna, M.A.; Orera, A.; Bobadilla, D.; Abarca, S.; Peña, O. Synthesis and Magnetic Properties of Nanostructured metallic Co, Mn and Ni oxide materials obtained from solid-state macromolecular complex precursors. RSC Adv. 2017, 7, 27729–27736. [Google Scholar] [CrossRef]
  46. Diaz, C.; Valenzuela, M.L.; Bobadilla, D.; Laguna-Bercero, M.A. Bimetallic Au//Ag Alloys Inside SiO2 using a solid-state method. J. Clust. Chem. 2017, 28, 2809–2815. [Google Scholar] [CrossRef]
  47. Diaz, C.; Valenzuela, M.L.; Garcia, C.; De la Campa, R.; Presa-Soto, A. Solid-state synthesis of pure and doped lanthanides oxide nanomaterials by using polymer templates. Study of their luminescent properties. Mater. Lett. 2017, 209, 111–114. [Google Scholar] [CrossRef]
  48. Diaz, C.; Valenzuela, M.L.; Segovia, M.; De la Campa, R.; Presa-Soto, A. Solution, Solid-State Two Step Synthesis and Optical Properties of ZnO and SnO Nanoparticles and Their Nanocomposites with SiO2. J. Clust. Sci. 2018, 29, 251–266. [Google Scholar] [CrossRef]
  49. Allende, P.; Laguna, M.; Barrientos, L.; Valenzuela, M.L.; Diaz, C. Solid State Tuning Morphology, Crystal Phase and Size through Metal Macromolecular Complexes and Its Significance in the Photocatalytic Response. ACS Appl. Energy Mater. 2018, 1, 3159–3170. [Google Scholar] [CrossRef]
  50. Díaz, C.; Carrillo, D.; De la Campa, R.; Pres-Soto, A.; Valenzuela, M.L. Solid-State synthesis of LnOCl/Ln2O3 (Ln = Eu,Nd) by using chitosan and PS-co-P4VP as polymeric supports. J. Rare Earth 2018, 36, 1326–1332. [Google Scholar] [CrossRef]
  51. Allende, P.; Barrientos, L.; Orera, A.; Laguna-Bercero, M.A.; Salazar, N.; Valenzuela, M.L.; Díaz, C. TiO2/SiO2 Composite for Efficient Protection of UVA and UVB Rays Through of a Solvent-Less Synthesis. J. Clust. Sci. 2019, 30, 1511–1517. [Google Scholar] [CrossRef]
  52. Cortes, M.A.; De la Campa, R.; Valenzuela, M.L.; Díaz, C.; Carriedo, G.A.; Presa-Soto, A. Cylindrical Micelles by the Self-Assembly of Crystalline-b-Coil Polyphosphazene-b-P2VP Block Copolymers. Stabilization of Gold Nanoparticles. Molecules 2019, 24, 1772. [Google Scholar] [CrossRef]
  53. Díaz, C.; Valenzuela, M.L.; Cifuentes-Vaca, O.; Segovia, M.; Laguna-Bercero, M.A. Incorporation of Nanostructured ReO3 in Silica Matrix and Their Activity Toward Photodegradation of Blue Methylene. J. Inorg. Organomet. Polym. Mater. 2020, 30, 1726–1734. [Google Scholar] [CrossRef]
  54. Díaz, C.; Valenzuela, M.L.; Cifuentes-Vaca, O.; Segovia, M.; Laguna-Bercero, M.A. Iridium nanostructured metal oxide, its inclusion in Silica matrix and their activity toward Photodegradation of Methylene Blue. Mater. Chem. Phys. 2020, 252, 123276. [Google Scholar] [CrossRef]
  55. Díaz, C.; Valenzuela, M.L.; Cifuentes-Vaca, O.; Segovia, M. Polymer precursors effect in the macromolecular metal-polymer on the Rh/RhO2/Rh2O3 phase using solvent-less synthesis and its photocatalytic activity. J. Inorg. Organomet. Polym. Mater. 2020, 30, 4702–4708. [Google Scholar] [CrossRef]
  56. Díaz, C.; Valenzuela, M.L.; Cifuentes-Vaca, O.; Segovia, M.; Laguna-Bercero, M.A. Incorporation of NiO into SiO2, TiO2, Al2O3, and Na4.2Ca2.8(Si6O18) Matrices: Medium Effect on the Optical Properties and Catalytic Degradation of Methylene Blue. Nanomaterials 2020, 10, 2470. [Google Scholar] [CrossRef]
  57. Díaz, C.; Valenzuela, M.L.; Laguna-Bercero, M.A.; Mendoza, K.; Cartes, P. Solventless preparation of thoria, their inclusion inside SiO2 and TiO2, their luminescent properties and their photocatalytic behavior. ACS Omega 2021, 6, 9391–9400. [Google Scholar] [CrossRef] [PubMed]
  58. Allende, P.; Orera, A.; Díaz, C.; Valenzuela, M.L.; Laguna-Bercero, M.A.; Barrientos, L. Insights of the formation mechanism of nanostructured titanium oxide polymorphs from different macromolecular metal-complex precursors. Heliyon 2021, 7, e07684. [Google Scholar] [CrossRef] [PubMed]
  59. Díaz, C.; Valenzuela, M.L.; Baez, R.; Segovia, M. Solid State Morphology and Size Tuning of Nanostructured Platinum Using Macromolecular Complexes. J. Chil. Chem. Soc. 2015, 60, 2986–2990. [Google Scholar] [CrossRef]
  60. Zhang, L.; Bai, S.; You, H.; Wu, H.; Peng, O.; Li, W.; Cao, K.; Zhou, Y. Submicrometre-sized EuPO4 hollow spheres: Template-directed synthesis and luminescent properties. Micro Nano Lett. 2019, 14, 309–312. [Google Scholar] [CrossRef]
  61. Tappan, B.; Steiner, S.; Luther, E. Nanoporous Metal Foams. Angew. Chem. 2010, 49, 4544–4565. [Google Scholar] [CrossRef]
  62. Kamarulzaman, N.; Kasim, M.F.; Rusdi, R. Band Gap Narrowing and Widening of ZnO Nanostructures and Doped Material. Nanoscale Res. Lett. 2015, 10, 346–358. [Google Scholar] [CrossRef]
  63. Prokofiev, A.M.; Shelykh, A.I.; Melekh, B.T. Periodicity in the band gap variation of Ln2 × 3 (X = O, S, Se) in the lanthanide series. J. Alloys Compd. 1996, 242, 41–44. [Google Scholar] [CrossRef]
  64. Wakefield, G.; Keron, H.A.; Dobson, P.J.; Hutchison, J.L. Synthesis and Properties of Sub-50-nm Europium Oxide Nanoparticles. J. Colloid Interface Sci. 1999, 215, 179–182. [Google Scholar] [CrossRef] [PubMed]
  65. Yang, K.S.; Wu, A.; Zhao, X.; Yan, Y.; Guo, X.; Bian, Y.; Bao, J.; Lia, W.; Zhu, X. Controlled synthesis of EuPO4 nano/microstructures and core–shell SiO2@EuPO4 nanostructures with improved photoluminescence. RSC Adv. 2017, 7, 52238–52244. [Google Scholar] [CrossRef]
  66. Yang, Y. Synthesis and luminescent properties of LaPO4:Eu3+ microspheres. Mater. Sci. Eng. B 2013, 178, 807–810. [Google Scholar] [CrossRef]
  67. Zollfrank, C.; Scheel, H.; Brungs, S.; Greil, P. Europium (III) Orthophosphates: Synthesis, Characterization, and Optical Properties. Cryst. Growth Des. 2008, 8, 766–770. [Google Scholar] [CrossRef]
  68. Binnemans, K. Interpretation of europium (III) spectra. Coord. Chem. Rev. 2015, 295, 1–45. [Google Scholar] [CrossRef]
Photochem 04 00018 g001
Figure 1. Schematic representation of polyphosphazene homopolymers, random copolymers, and block copolymers.
Figure 1. Schematic representation of polyphosphazene homopolymers, random copolymers, and block copolymers.
Photochem 04 00018 g001
Photochem 04 00018 g002
Figure 2. TG/DTA traces of (1a) (a) and TG/DTA traces of (1a-Zn) (b).
Figure 2. TG/DTA traces of (1a) (a) and TG/DTA traces of (1a-Zn) (b).
Photochem 04 00018 g002
Photochem 04 00018 g003
Figure 3. X-ray diffraction pattern of PtCl2-based materials, (1a-Pt, black line), (1b-Pt, blue line), and (1c-Pt, red line), after pyrolysis.
Figure 3. X-ray diffraction pattern of PtCl2-based materials, (1a-Pt, black line), (1b-Pt, blue line), and (1c-Pt, red line), after pyrolysis.
Photochem 04 00018 g003
Photochem 04 00018 g004
Figure 4. X-ray diffraction pattern of ZnCl2-based materials, (1a-Zn, black line), (1b-Zn, red line), and (1c-Zn, blue line), after pyrolysis.
Figure 4. X-ray diffraction pattern of ZnCl2-based materials, (1a-Zn, black line), (1b-Zn, red line), and (1c-Zn, blue line), after pyrolysis.
Photochem 04 00018 g004
Photochem 04 00018 g005
Figure 5. X-ray diffraction pattern of Eu(NO3)3-based materials, (1a-Eu, black line), (1b-Eu, red line), and (1c-Eu, blue line), after pyrolysis.
Figure 5. X-ray diffraction pattern of Eu(NO3)3-based materials, (1a-Eu, black line), (1b-Eu, red line), and (1c-Eu, blue line), after pyrolysis.
Photochem 04 00018 g005
Photochem 04 00018 g006
Figure 6. SEM images of nanostructured Pt prepared by pyrolysis of (a) (1a-Pt), (b) (1b-Pt), and (c) (1c-Pt). EDS analysis of (1c-Pt) (d).
Figure 6. SEM images of nanostructured Pt prepared by pyrolysis of (a) (1a-Pt), (b) (1b-Pt), and (c) (1c-Pt). EDS analysis of (1c-Pt) (d).
Photochem 04 00018 g006
Photochem 04 00018 g007
Figure 7. SEM images of the ZnO from (a) (1a-Zn), (b) (1b-Zn), and (c) (1c-Zn). EDS analysis of (1c-(1c-Zn) (d).
Figure 7. SEM images of the ZnO from (a) (1a-Zn), (b) (1b-Zn), and (c) (1c-Zn). EDS analysis of (1c-(1c-Zn) (d).
Photochem 04 00018 g007
Photochem 04 00018 g008
Figure 8. SEM images of Eu2O3 from (a) (1a-Eu), (b) (1b-Eu), and (c) (1c-Eu). EDS analysis of (1c-(1c-Eu) (d).
Figure 8. SEM images of Eu2O3 from (a) (1a-Eu), (b) (1b-Eu), and (c) (1c-Eu). EDS analysis of (1c-(1c-Eu) (d).
Photochem 04 00018 g008
Photochem 04 00018 g009
Figure 9. TEM images of Pt nanoparticles prepared by pyrolysis of the following macromolecular precursors: (a) (1a-Pt) and (b) electron diffraction images; (c) the Pt sample from (1b-Pt); (d) (1c-Pt) and (e) electron diffraction images.
Figure 9. TEM images of Pt nanoparticles prepared by pyrolysis of the following macromolecular precursors: (a) (1a-Pt) and (b) electron diffraction images; (c) the Pt sample from (1b-Pt); (d) (1c-Pt) and (e) electron diffraction images.
Photochem 04 00018 g009
Photochem 04 00018 g010
Figure 10. TEM images of ZnO from (a) (1a-Zn), (c) (1b-Zn), and (e) (1c-Zn), their electron diffractions (b), as well as (d,f) their histograms (right side).
Figure 10. TEM images of ZnO from (a) (1a-Zn), (c) (1b-Zn), and (e) (1c-Zn), their electron diffractions (b), as well as (d,f) their histograms (right side).
Photochem 04 00018 g010
Photochem 04 00018 g011
Figure 11. TEM images of Eu2O3 from the (a) (1a-Eu), (c) (1b-Eu), and (e) (1c-Eu) precursors, their electron diffractions (b), as well as (d,f) their histograms (right side).
Figure 11. TEM images of Eu2O3 from the (a) (1a-Eu), (c) (1b-Eu), and (e) (1c-Eu) precursors, their electron diffractions (b), as well as (d,f) their histograms (right side).
Photochem 04 00018 g011
Photochem 04 00018 g012
Figure 12. X-ray diffraction patterns of nanostructured EuPO4 obtained by pyrolysis of the block copolymer precursors, (2a-Eu, blue line), (2b-Eu, red line), and (2c-Eu, black line).
Figure 12. X-ray diffraction patterns of nanostructured EuPO4 obtained by pyrolysis of the block copolymer precursors, (2a-Eu, blue line), (2b-Eu, red line), and (2c-Eu, black line).
Photochem 04 00018 g012
Photochem 04 00018 g013
Figure 13. SEM images of nanostructured EuPO4 synthesized by pyrolysis of (a) (2a-Eu), (b) (2b-Eu), and (c) (2c-Eu). (d) EDS analysis of (2c-Eu).
Figure 13. SEM images of nanostructured EuPO4 synthesized by pyrolysis of (a) (2a-Eu), (b) (2b-Eu), and (c) (2c-Eu). (d) EDS analysis of (2c-Eu).
Photochem 04 00018 g013
Photochem 04 00018 g014
Figure 14. TEM analysis of the nanostructured EuPO4 synthesized by pyrolysis of (a) (2a-Eu), (c) (2b-Eu), and (e) (2c-Eu). Electron diffraction analysis (b,d,f).
Figure 14. TEM analysis of the nanostructured EuPO4 synthesized by pyrolysis of (a) (2a-Eu), (c) (2b-Eu), and (e) (2c-Eu). Electron diffraction analysis (b,d,f).
Photochem 04 00018 g014
Photochem 04 00018 g015
Figure 15. Luminescent spectra of nanostructured EuO3 synthesized by pyrolysis of (a) (1a-Eu) and (1b-Eu) and (b) (1c-Eu), as well as of EuPO4 from (c) (2a-Eu) and (2b-Eu) and (d) (2c-Eu).
Figure 15. Luminescent spectra of nanostructured EuO3 synthesized by pyrolysis of (a) (1a-Eu) and (1b-Eu) and (b) (1c-Eu), as well as of EuPO4 from (c) (2a-Eu) and (2b-Eu) and (d) (2c-Eu).
Photochem 04 00018 g015
Table 1. Relevant experimental data of the as-prepared nanostructured Pt, ZnO, Eu2O3, and EuPO4 materials.
Table 1. Relevant experimental data of the as-prepared nanostructured Pt, ZnO, Eu2O3, and EuPO4 materials.
Precursor/NanoparticlesSize nm [a]MorphologyOptical PropertiesDegree Coordination
(%) [b]
Eg
(eV)		Uv
(nm)
1a-Zn/ZnO70Aggregated grains with hexagonal-like architecture3.23310
372		71
1b-Zn/ZnO60Aggregated grains3.1433164
1c-Zn/ZnO80Aggregated grains with hexagonal-like architecture4.24309
390
610
656		47
1a-Eu/Eu2O359Aggregated grains with porous surfaces4.52-57
1b-Eu/Eu2O361Aggregated grains with porous surfaces4.34-55
1c-Eu/Eu2O352Aggregated grains with porous surfaces4.37-57
1a-Pt/Pt62Aggregated grains-29285
1b-Pt/Pt47Metallic foam-29083
1c-Pt/Pt95Metallic foam-29285
2a-Eu [c]/EuPO425–40 Porous material--54
2b-Eu [c]/EuPO425–40 Porous material--53
2c-Eu [c]/EuPO425–40 Porous material--50
[a] Determined by TEM. [b] Degree of coordination of the corresponding metal source with the respective polymer material. Calculated by TG/DTA. [c] [PP] = [N=P(OCH2CF3)2]n.
Disclaimer/Publisher’s Note: The statements, opinions and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s). MDPI and/or the editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, methods, instructions or products referred to in the content.

Share and Cite

MDPI and ACS Style

Cortés, M.Á.; Díaz, C.; de la Campa, R.; Presa-Soto, A.; Valenzuela, M.L. Synthesis of Metallic and Metal Oxide Nanoparticles Using Homopolymers as Solid Templates: Luminescent Properties of the Eu+3 Nanoparticle Products. Photochem 2024, 4, 302-318. https://doi.org/10.3390/photochem4030018

AMA Style

Cortés MÁ, Díaz C, de la Campa R, Presa-Soto A, Valenzuela ML. Synthesis of Metallic and Metal Oxide Nanoparticles Using Homopolymers as Solid Templates: Luminescent Properties of the Eu+3 Nanoparticle Products. Photochem. 2024; 4(3):302-318. https://doi.org/10.3390/photochem4030018

Chicago/Turabian Style

Cortés, María Ángeles, Carlos Díaz, Raquel de la Campa, Alejandro Presa-Soto, and María Luisa Valenzuela. 2024. "Synthesis of Metallic and Metal Oxide Nanoparticles Using Homopolymers as Solid Templates: Luminescent Properties of the Eu+3 Nanoparticle Products" Photochem 4, no. 3: 302-318. https://doi.org/10.3390/photochem4030018

Article Metrics

Back to TopTop