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19 pages, 5243 KiB

Open AccessArticle

Fabrication of Ternary MoS₂/CdS/Bi₂S₃-Based Nano Composites for Photocatalytic Dye Degradation

by Asif Nazir, Muhammad Suleman Tahir, Ghulam Mustafa Kamal, Xu Zhang, Muhammad Bilal Tahir, Bin Jiang and Muhammad Safdar

Molecules 2023, 28(7), 3167; https://doi.org/10.3390/molecules28073167 - 2 Apr 2023

Cited by 3 | Viewed by 2005

Abstract

The synthesis and design of low-cost visible-light-active catalysts for the photodegradation of organic dyes have been regarded as an efficient way to use solar energy in addressing environmental issues. We report the fabrication of MoS₂/CdS nanoparticles functionalized with Bi₂S [...] Read more.

The synthesis and design of low-cost visible-light-active catalysts for the photodegradation of organic dyes have been regarded as an efficient way to use solar energy in addressing environmental issues. We report the fabrication of MoS₂/CdS nanoparticles functionalized with Bi₂S₃ nanoflakes. The ternary composites of “MoS₂/CdS/Bi₂S₃” were synthesized in situ by a hydrothermal method at different temperatures. The changes in structural, optical, and morphological properties of the synthesized CdS/MoS₂/Bi₂S₃ were explored. The effects of Bi₂S₃ on CdS/MoS₂ were thoroughly studied by performing an X-ray diffractometer (XRD), a scanning electron microscope (SEM), an ultra-violet–visible spectrometer (Uv–vis), and Fourier transform infrared spectroscopic (FT-IR) studies of the nanoparticles. XRD confirms the cubical crystal structure of the nanoparticles. SEM studies possess the modulation in the surface morphology with the tenability in volume ratios of “MoS₂/CdS/Bi₂S₃” composites. It was observed that the bandgaps calculated using absorption measurements could be manipulated from 2.40 eV to 0.97 eV with varying Bi₂S₃ in the MoS₂/CdS nanostructures. FT-IR confirmed the synthesis of “MoS₂/CdS/Bi₂S₃” nanoparticles. On allowing the visible light to fall for 120 min, it was observed that “MoS₂/CdS/Bi₂S₃” degrades the methylene blue up to 90%. The calculated results of “MoS₂/CdS/Bi₂S₃” suggest that the synthesized material could be a strong candidate for photodegradation applications. This research work explains the synthesis of MoS₂/CdS/Bi₂S₃-based nanocomposites for the degradation of dye using a photocatalytic process. The final results show that this catalyst effectively degrades the dye. Full article

(This article belongs to the Special Issue Preparation of Innovative Nanomaterials for Water/Air Purification)

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15 pages, 4057 KiB

Open AccessArticle

Hemispherical Solar Distiller Performance Utilizing Hybrid Storage Media, Paraffin Wax with Nanoparticles: An Experimental Study

by Ravishankar Sathyamurthy, Wael M. El-Maghlany, Mohammed El Hadi Attia, A. E. Kabeel, Mohamed Abdelgaied, Moataz M. Abdel-Aziz, A. S. Abdullah and S. Vasanthaseelan

Molecules 2022, 27(24), 8988; https://doi.org/10.3390/molecules27248988 - 16 Dec 2022

Cited by 8 | Viewed by 1468

Abstract

The traditional method of obtaining fresh water for drinking is by burning fossil fuels, emitting greenhouse gases into the atmosphere. However, renewable energy is gaining more traction since it is available free of cost for producing fresh water. In this study, Al₂ [...] Read more.

The traditional method of obtaining fresh water for drinking is by burning fossil fuels, emitting greenhouse gases into the atmosphere. However, renewable energy is gaining more traction since it is available free of cost for producing fresh water. In this study, Al₂O₃ nanoparticles were distributed in a phase change material (paraffin wax) that had been fixed at a hemispherical distiller water basin. Three scenarios with three hemispherical distillers were examined. A conventional hemispherical distiller (CHD), a conventional hemispherical distiller with paraffin wax as a phase change material (CHD-PCM), and a conventional hemispherical distiller with PCM partially filled with Al₂O₃ nanoparticles (CHD-N-PCM) were tested under the same climatic conditions. The experimental results showed that CHD gave a daily yield of 4.85 L/m²/day, while CHD-PCM increased the yield to up to 6.2 L/m²/day with a 27.84% daily yield enhancement. The addition of Al₂O₃ nanoparticles to paraffin wax CHD-N-PCM improved hemispherical distillate yield up to 8.3 L/m²/day with a 71.13% increase over CHD yield. Full article

(This article belongs to the Special Issue Preparation of Innovative Nanomaterials for Water/Air Purification)

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11 pages, 2903 KiB

Open AccessArticle

Photocatalytic Oxidation of Carbon Monoxide Using Synergy of Redox-Separated Photocatalyst and Ozone

by Seunghyun Weon

Molecules 2022, 27(23), 8482; https://doi.org/10.3390/molecules27238482 - 2 Dec 2022

Viewed by 1309

Abstract

Separating the redox centers of photocatalysts is the most promising strategy to enhance photocatalytic oxidation efficiency. Herein, I investigate a site-selective loading of Pt on facet-engineered TiO₂ to achieve carbon monoxide (CO) oxidation at room temperature. Spatially loaded Pt on {101} facets [...] Read more.

Separating the redox centers of photocatalysts is the most promising strategy to enhance photocatalytic oxidation efficiency. Herein, I investigate a site-selective loading of Pt on facet-engineered TiO₂ to achieve carbon monoxide (CO) oxidation at room temperature. Spatially loaded Pt on {101} facets of TiO₂ attracts photoinduced electrons efficiently. Thereby, oxygen dissociation is facilitated on the Pt surface, which is confirmed by enhanced oxidation of CO by 2.4 times compared to the benchmark of Pt/TiO₂. The remaining holes on TiO₂ can be utilized for the oxidation of various gaseous pollutants. Specifically, gaseous ozone, which is present in indoor and ambient air, is converted to a hydroxyl radical by reacting with the hole; thus, the poisoned Pt surface is continuously cleaned during the CO oxidation, as confirmed by in situ diffuse reflectance infrared transform spectroscopy. While randomly loaded Pt can act as recombination center, reducing photocatalytic activity, redox-separated photocatalyst enhances charge separation, boosting CO oxidation and catalyst regeneration via simultaneous ozone decomposition. Full article

(This article belongs to the Special Issue Preparation of Innovative Nanomaterials for Water/Air Purification)

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21 pages, 3457 KiB

Open AccessArticle

Highly Selective Methodology for Entrapment and Subsequent Removal of Cobalt (II) Ions under Optimized Conditions by Micellar-Enhanced Ultrafiltration

by Amnah Yusaf, Muhammad Usman, Matloob Ahmad, Muhammad Siddiq, Asim Mansha, Sami A. Al-Hussain, Magdi E. A. Zaki and Hafiza Fatima Rehman

Molecules 2022, 27(23), 8332; https://doi.org/10.3390/molecules27238332 - 29 Nov 2022

Cited by 6 | Viewed by 1273

Abstract

Micellar-enhanced ultrafiltration (MEUF), being a separation technique, was used to remove cobalt metal ion (Co²⁺) from their aqueous solutions in an application to reduce the toxicity level from industrial effluents using a micellar solution of anionic and cationic surfactants. The metal [...] Read more.

Micellar-enhanced ultrafiltration (MEUF), being a separation technique, was used to remove cobalt metal ion (Co²⁺) from their aqueous solutions in an application to reduce the toxicity level from industrial effluents using a micellar solution of anionic and cationic surfactants. The metal ions were first adsorbed by using anionic surfactants, i.e., sodium dodecyl sulfate (SDS) and sodium oleate (SO). The calculations for partition (K_x) and binding constants (K_b) and their respective free energy of partition and binding (ΔG_p and ΔG_b kJmol⁻¹) helped significantly to find out the extent of binding or interaction of Co²⁺ with the surfactant and ΔG_p and ΔG_b were found to be −29.50 and −19.38 kJmol⁻¹ for SDS and −23.95 and −12.67 kJmol⁻¹ in the case of SO. MEUF work was also performed to find out the optimal conditions to remove metal pollutants from the aqueous system. For the said purpose, various factors and concentrations effect were studied, such as the concentration of the surfactant, concentration of the electrolyte (NaCl), transmembrane pressure, RPM, and pH. The efficiency of this process was checked by calculating various parameters, such as rejection percentage (R%) and permeate flux (J). A maximum rejection of 99.95% with SDS and 99.99% with SO was attained. Full article

(This article belongs to the Special Issue Preparation of Innovative Nanomaterials for Water/Air Purification)

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17 pages, 4759 KiB

Open AccessArticle

Transformation of Residual Açai Fruit (Euterpe oleracea) Seeds into Porous Adsorbent for Efficient Removal of 2,4-Dichlorophenoxyacetic Acid Herbicide from Waters

by Rolando Ramirez, Carlos Eduardo Schnorr, Jordana Georgin, Matias Schadeck Netto, Dison S. P. Franco, Elvis Carissimi, Delmira Wolff, Luis F. O. Silva and Guilherme Luiz Dotto

Molecules 2022, 27(22), 7781; https://doi.org/10.3390/molecules27227781 - 11 Nov 2022

Cited by 11 | Viewed by 1559

Abstract

Brazil’s production and consumption of açai pulp (Euterpe oleracea) occur on a large scale. Most of the fruit is formed by the pit, which generates countless tons of residual biomass. A new purpose for this biomass, making its consumption highly sustainable, was presented [...] Read more.

Brazil’s production and consumption of açai pulp (Euterpe oleracea) occur on a large scale. Most of the fruit is formed by the pit, which generates countless tons of residual biomass. A new purpose for this biomass, making its consumption highly sustainable, was presented in this study, where activated carbon (AC) was produced with zinc chloride for later use as an adsorbent. AC carbon formed by carbon and with a yield of 28 % was satisfactorily used as an adsorbent in removing the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D). Removal efficiency was due to the highly porous surface (Vp = 0.467 cm³ g⁻¹; Dp = 1.126 nm) and good surface área (SBET = 920.56 m² g⁻¹). The equilibrium data fit the Sips heterogeneous and homogeneous surface model better. It was observed that the increase in temperature favored adsorption, reaching a maximum experimental capacity of 218 mg g⁻¹ at 328 K. The thermodynamic behavior indicated a spontaneous, favorable, and endothermic behavior. The magnitude of the enthalpy of adsorption was in agreement with the physical adsorption. Regardless of the herbicide concentration, the adsorbent displayed fast kinetics, reaching equilibrium within 120 min. The linear driving force (LDF) model provided a strong statistical match to the kinetic curves. AC with zinc chloride (ZnCl₂), created from leftover açai biomass, is a potential alternative as an adsorbent for treating effluents containing 2,4-D. Full article

(This article belongs to the Special Issue Preparation of Innovative Nanomaterials for Water/Air Purification)

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14 pages, 3706 KiB

Open AccessArticle

Cation Incorporation and Synergistic Effects on the Characteristics of Sulfur-Doped Manganese Ferrites S@Mn(Fe₂O₄) Nanoparticles for Boosted Sunlight-Driven Photocatalysis

by Sohail Nadeem, Mehak Bukhari, Mohsin Javed, Shahid Iqbal, Mirza Nadeem Ahmad, Hamad Alrbyawi, Murefah Mana Al-Anazy, Eslam B. Elkaeed, H. H. Hegazy, Muhammad Abdul Qayyum, Rami Adel Pashameah, Eman Alzahrani and Abd-ElAziem Farouk

Molecules 2022, 27(22), 7677; https://doi.org/10.3390/molecules27227677 - 8 Nov 2022

Cited by 1 | Viewed by 1715

Abstract

In the present work, sulfur-doped manganese ferrites S@Mn(Fe₂O₄) nanoparticles were prepared by using the sol-gel and citrate method. The concentration of sulfur varied from 1 to 7% by adding Na₂S. The samples were characterized by performing Fourier [...] Read more.

In the present work, sulfur-doped manganese ferrites S@Mn(Fe₂O₄) nanoparticles were prepared by using the sol-gel and citrate method. The concentration of sulfur varied from 1 to 7% by adding Na₂S. The samples were characterized by performing Fourier Transformed Infrared Spectroscopy (FTIR), Energy Dispersive X-ray (EDX), X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) and Ultraviolet–Visible spectroscopy (UV–Visible). The synthesized sulfur-doped manganese ferrites were applied to evaluate the photocatalytic degradation of the dyes. Further, the degradation studies revealed that the nanoparticles successfully degraded the methylene blue dye by adding a 0.006 g dose under the sunlight. The sulfur-doped manganese ferrite nanoparticles containing 3% sulfur completely degraded the dye in 2 h and 15 min in aqueous medium. Thus, the ferrite nanoparticles were found to be promising photocatalyst materials and could be employed for the degradation of other dyes in the future. Full article

(This article belongs to the Special Issue Preparation of Innovative Nanomaterials for Water/Air Purification)

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18 pages, 6902 KiB

Open AccessArticle

rGO-WO₃ Heterostructure: Synthesis, Characterization and Utilization as an Efficient Adsorbent for the Removal of Fluoroquinolone Antibiotic Levofloxacin in an Aqueous Phase

by Manjot Kaur, Shafali Singh, Surinder Kumar Mehta and Sushil Kumar Kansal

Molecules 2022, 27(20), 6956; https://doi.org/10.3390/molecules27206956 - 17 Oct 2022

Cited by 7 | Viewed by 1607

Abstract

Herein, the heterostructure rGO-WO₃ was hydrothermally synthesized and characterized by HRTEM (high-resolution transmission electron microscopy), FESEM (field emission scanning electron microscopy), XRD (X-ray diffraction), FT-IR (Fourier transform infrared spectroscopy), XPS (X-ray photoelectron microscopy), nitrogen physisorption isotherm, Raman, TGA (thermogravimetric analysis) and zeta [...] Read more.

Herein, the heterostructure rGO-WO₃ was hydrothermally synthesized and characterized by HRTEM (high-resolution transmission electron microscopy), FESEM (field emission scanning electron microscopy), XRD (X-ray diffraction), FT-IR (Fourier transform infrared spectroscopy), XPS (X-ray photoelectron microscopy), nitrogen physisorption isotherm, Raman, TGA (thermogravimetric analysis) and zeta potential techniques. The HRTEM and FESEM images of the synthesized nanostructure revealed the successful loading of WO₃ nanorods on the surface of rGO nanosheets. The prepared heterostructure was utilized as an efficient adsorbent for the removal of a third-generation fluoroquinolone antibiotic, i.e., levofloxacin (LVX), from water. The adsorption equilibrium data were appropriately described by a Langmuir isotherm model. The prepared rGO-WO₃ heterostructure exhibited a Langmuir adsorption capacity of 73.05 mg/g. The kinetics of LVX adsorption followed a pseudo-second-order kinetic model. The adsorption of LVX onto the rGO-WO₃ heterostructure was spontaneous and exothermic in nature. Electrostatic interactions were found to have played a significant role in the adsorption of LVX onto the rGO-WO₃ heterostructure. Thus, the prepared rGO-WO₃ heterostructure is a highly promising material for the removal of emerging contaminants from aqueous solution. Full article

(This article belongs to the Special Issue Preparation of Innovative Nanomaterials for Water/Air Purification)

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16 pages, 3916 KiB

Open AccessArticle

Integration of Mn-ZnFe₂O₄ with S-g-C₃N₄ for Boosting Spatial Charge Generation and Separation as an Efficient Photocatalyst

by Mohsin Javed, Waleed Bin Khalid, Shahid Iqbal, Muhammad Azam Qamar, Hamad Alrbyawi, Nasser S. Awwad, Hala A. Ibrahium, Murefah Mana Al-Anazy, Eslam B. Elkaeed, Rami Adel Pashameah, Eman Alzahrani and Abd-ElAziem Farouk

Molecules 2022, 27(20), 6925; https://doi.org/10.3390/molecules27206925 - 15 Oct 2022

Cited by 5 | Viewed by 1888

Abstract

The disposal of dyes and organic matter into water bodies has become a significant source of pollution, posing health risks to humans worldwide. With rising water demands and dwindling supplies, these harmful compounds must be isolated from wastewater and kept out of the [...] Read more.

The disposal of dyes and organic matter into water bodies has become a significant source of pollution, posing health risks to humans worldwide. With rising water demands and dwindling supplies, these harmful compounds must be isolated from wastewater and kept out of the aquatic environment. In the research presented here, hydrothermal synthesis of manganese-doped zinc ferrites’ (Mn-ZnFe₂O₄) nanoparticles (NPs) and their nanocomposites (NCs) with sulfur-doped graphitic carbon nitride (Mn-ZnFe₂O₄/S-g-C₃N₄) are described. The samples’ morphological, structural, and bonding features were investigated using SEM, XRD, and FTIR techniques. A two-phase photocatalytic degradation study of (0.5, 1, 3, 5, 7, 9, and 11 wt.%) Mn-doped ZnFe₂O₄ NPs and Mn-ZnFe₂O₄/(10, 30, 50, 60, and 70 wt.%) S-g-C₃N₄ NCs against MB was carried out to find the photocatalyst with maximum efficiency. The 9% Mn-ZnFe₂O₄ NPs and Mn-ZnFe₂O₄/50% S-g-C₃N₄ NCs exhibited the best photocatalyst efficiency in phase one and phased two, respectively. The enhanced photocatalytic activity of the Mn-ZnFe₂O₄/50% S-g-C₃N₄ NCs could be attributed to synergistic interactions at the Mn-ZnFe₂O₄/50% S-g-C₃N₄ NCs interface that resulted in a more effective transfer and separation of photo-induced charges. Therefore, it is efficient, affordable, and ecologically secure to modify ZnFe₂O₄ by doping with Mn and homogenizing with S-g-C₃N₄. As a result, our current research suggests that the synthetic ternary hybrid Mn-ZnFe₂O₄/50% S-g-C₃N₄ NCs may be an effective photocatalytic system for degrading organic pollutants from wastewater. Full article

(This article belongs to the Special Issue Preparation of Innovative Nanomaterials for Water/Air Purification)

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18 pages, 2281 KiB

Open AccessArticle

Mixed Micellar Solubilization of Naphthol Green B Followed by Its Removal from Synthetic Effluent by Micellar-Enhanced Ultrafiltration under Optimized Conditions

by Amnah Yusaf, Muhammad Usman, Muhammad Siddiq, Manahil Bakhtiar, Asim Mansha, Saadia Shaukat and Hafiza Fatima Rehman

Molecules 2022, 27(19), 6436; https://doi.org/10.3390/molecules27196436 - 29 Sep 2022

Cited by 9 | Viewed by 2055

Abstract

In this manuscript, the application of cetyltrimethylammonium bromide (CTAB) and cetylpyridinium chloride (CPC) for the removal of Naphthol Green B (NGB) as a synthetic effluent has been studied. The solubilization of NGB by a single and mixed micellar system using Triton X-100 (TX-100) [...] Read more.

In this manuscript, the application of cetyltrimethylammonium bromide (CTAB) and cetylpyridinium chloride (CPC) for the removal of Naphthol Green B (NGB) as a synthetic effluent has been studied. The solubilization of NGB by a single and mixed micellar system using Triton X-100 (TX-100) as a nonionic surfactant has been performed to establish both the extent of the partitioning (k_x) of NGB and ultimately their respective Gibbs free energies ΔG_p as well. An applied methodology, micellar-enhanced ultrafiltration (MEUF), has also been studied in different micellar media of cationic surfactants by variation in some selective parameters, such as the concentration of surfactant, electrolyte, pressure, pH, and RPM to obtain optimum conditions. The results have been analyzed by a UV/visible double beam spectrophotometer. ΔG_p was found to be −39.65 kJ/mol and −47.94 kJ/mol by CTAB and CPC, respectively, in the presence of a nonionic surfactant. The maximum value of Gibbs free energy (ΔG_p) of the partition was obtained by CPC. The values of the rejection coefficient (R%) and permeate flux (J) are also calculated. A maximum removal of 99.77% and 98.53% by CTAB and CPC, respectively, was obtained. It has been observed that both of the surfactants are strong candidates for NGB removal. Full article

(This article belongs to the Special Issue Preparation of Innovative Nanomaterials for Water/Air Purification)

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15 pages, 2794 KiB

Open AccessArticle

Fabrication of Cr-ZnFe₂O₄/S-g-C₃N₄ Heterojunction Enriched Charge Separation for Sunlight Responsive Photocatalytic Performance and Antibacterial Study

by Ping Zhang, Tehreem Munawar, Raya Soltane, Mohsin Javed, Guocong Liu, Shahid Iqbal, Muhammad Azam Qamar, Ayed A. Dera, Hamad Alrbyawi, M. Alfakeer, Sameh Rabea and Eslam B. Elkaeed

Molecules 2022, 27(19), 6330; https://doi.org/10.3390/molecules27196330 - 26 Sep 2022

Cited by 6 | Viewed by 1594

Abstract

There has been a lot of interest in the manufacture of stable, high-efficiency photocatalysts. In this study, initially Cr doped ZnFe₂O₄ nanoparticles (NPs) were made via surfactant-assisted hydrothermal technique. Then Cr-ZnFe₂O₄ NPs were modified by incorporating S-g-C [...] Read more.

There has been a lot of interest in the manufacture of stable, high-efficiency photocatalysts. In this study, initially Cr doped ZnFe₂O₄ nanoparticles (NPs) were made via surfactant-assisted hydrothermal technique. Then Cr-ZnFe₂O₄ NPs were modified by incorporating S-g-C₃N₄ to enhance their photocatalytic efficiency. The morphological, structural, and bonding aspects were analyzed by XRD, FTIR, and SEM techniques. The photocatalytic efficiency of the functional Cr-ZnFe₂O₄/S-g-C₃N₄ (ZFG) heterostructure photocatalysts was examined against MB under sunlight. The produced ZFG-50 composite has the best photocatalytic performance, which is 2.4 and 3.5 times better than that of ZnFe₂O₄ and S-g-C₃N₄, respectively. Experiments revealed that the enhanced photocatalytic activity of the ZFG nanocomposite was caused by a more effective transfer and separation of photo-induced charges. The ZFG photocatalyst can use sunlight for treating polluted water, and the proposed modification of ZnFe₂O₄ using Cr and S-g-C₃N₄ is efficient, affordable, and environmentally benign. Under visible light, Gram-positive and Gram-negative bacteria were employed to ZFG-50 NCs’ antimicrobial activity. These ZFG-50 NCs also exhibit excellent antibacterial potential. Full article

(This article belongs to the Special Issue Preparation of Innovative Nanomaterials for Water/Air Purification)

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23 pages, 9529 KiB

Open AccessArticle

Polyaniline Modified CNTs and Graphene Nanocomposite for Removal of Lead and Zinc Metal Ions: Kinetics, Thermodynamics and Desorption Studies

by Imran Ali, Tatiana S. Kuznetsova, Alexander E. Burakov, Irina V. Burakova, Tatiana V. Pasko, Tatiana P. Dyachkova, Elina S. Mkrtchyan, Alexander V. Babkin, Alexey G. Tkachev, Hassan M. Albishri, Wael Hamad Alshitari, Ahmed M. Hameed and Ahmed Alharbi

Molecules 2022, 27(17), 5623; https://doi.org/10.3390/molecules27175623 - 31 Aug 2022

Cited by 14 | Viewed by 1756

Abstract

A novel polyaniline-modified CNT and graphene-based nanocomposite (2.32–7.34 nm) was prepared and characterized by spectroscopic methods. The specific surface area was 176 m²/g with 0.232 cm³/g as the specific pore volume. The nanocomposite was used to remove zinc and [...] Read more.

A novel polyaniline-modified CNT and graphene-based nanocomposite (2.32–7.34 nm) was prepared and characterized by spectroscopic methods. The specific surface area was 176 m²/g with 0.232 cm³/g as the specific pore volume. The nanocomposite was used to remove zinc and lead metal ions from water; showing a high removal capacity of 346 and 581 mg/g at pH 6.5. The data followed pseudo-second-order, intraparticle diffusion and Elovich models. Besides this, the experimental values obeyed Langmuir and Temkin isotherms. The results confirmed that the removal of lead and zinc ions occurred in a mixed mode, that is, diffusion absorption and ion exchange between the heterogeneous surface of the sorbent containing active adsorption centers and the solution containing metal ions. The enthalpy values were 149.9 and 158.6 J.mol⁻¹K⁻¹ for zinc and lead metal ions. The negative values of free energies were in the range of −4.97 to −26.3 kJ/mol. These values indicated an endothermic spontaneous removal of metal ions from water. The reported method is useful to remove the zinc and lead metal ions in any water body due to the high removal capacity of nanocomposite at natural pH of 6.5. Moreover, a low dose of 0.005 g per 30 mL made this method economical. Furthermore, a low contact time of 15 min made this method applicable to the removal of the reported metal ions from water in a short time. Briefly, the reported method is highly economical, nature-friendly and fast and can be used to remove the reported metal ions from any water resource. Full article

(This article belongs to the Special Issue Preparation of Innovative Nanomaterials for Water/Air Purification)

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16 pages, 3230 KiB

Open AccessArticle

Synthesis of a Magnetic Carnation-like Hydroxyapatite/Basic Calcium Carbonate Nanocomposite and Its Adsorption Behaviors for Lead Ions in Water

by Haifeng Guo, Siru Hu, Zongli Wang, Yutong Li, Xinshuang Guo, Ziling He, Wenbin Wang, Jun Feng, Kangyun Yang and Hong Zheng

Molecules 2022, 27(17), 5565; https://doi.org/10.3390/molecules27175565 - 29 Aug 2022

Cited by 3 | Viewed by 1526

Abstract

Calcium-enriched compounds have great potential in the treatment of heavy-metal contaminated wastewater. Preparing stable basic calcium carbonate (BCC), which is a calcium-enriched compound, and applying it in practice is a great challenge. This work investigated the formation process of hierarchical hydroxyapatite (HAP)/BCC nanocomposites [...] Read more.

Calcium-enriched compounds have great potential in the treatment of heavy-metal contaminated wastewater. Preparing stable basic calcium carbonate (BCC), which is a calcium-enriched compound, and applying it in practice is a great challenge. This work investigated the formation process of hierarchical hydroxyapatite (HAP)/BCC nanocomposites and their adsorption behaviors regarding lead ions (Pb²⁺). The morphology of the HAP/BCC nanocomposite was controlled by the addition of monododecyl phosphate (MDP). The carnation-like HAP/BCC nanocomposite was achieved with the addition of 30 g of MDP. The carnation-like HAP/BCC nanocomposite had a high Pb²⁺ adsorption capacity of 860 mg g⁻¹. The pseudo-second-order and Freundlich model simulation results indicated that the adsorptions of Pb²⁺ on the nanocomposites belonged to the chemisorption and multilayer adsorption processes. The main effective adsorption components for the nanocomposites were calcium-enriched HAP and BCC. Through the Ca²⁺ ions exchanging with Pb²⁺, the HAP and BCC phases were converted to hydroxyl-pyromorphite (Pb-HAP) and hydrocerussite (Pb₃(CO₃)₂(OH)₂), respectively. The carnation-like HAP/BCC nanocomposite has great potential in the treatment of heavy metal ions. This facile method provides a new method for preparing a stable HAP/BCC nanocomposite and applying it in practice. Full article

(This article belongs to the Special Issue Preparation of Innovative Nanomaterials for Water/Air Purification)

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Review

Jump to: Research

31 pages, 3931 KiB

Open AccessReview

Exploring Sustainable Agriculture with Nitrogen-Fixing Cyanobacteria and Nanotechnology

by Taufiq Nawaz, Liping Gu, Shah Fahad, Shah Saud, Bruce Bleakley and Ruanbao Zhou

Molecules 2024, 29(11), 2534; https://doi.org/10.3390/molecules29112534 - 28 May 2024

Viewed by 914

Abstract

The symbiotic relationship between nitrogen-fixing cyanobacteria and plants offers a promising avenue for sustainable agricultural practices and environmental remediation. This review paper explores the molecular interactions between nitrogen-fixing cyanobacteria and nanoparticles, shedding light on their potential synergies in agricultural nanotechnology. Delving into the [...] Read more.

The symbiotic relationship between nitrogen-fixing cyanobacteria and plants offers a promising avenue for sustainable agricultural practices and environmental remediation. This review paper explores the molecular interactions between nitrogen-fixing cyanobacteria and nanoparticles, shedding light on their potential synergies in agricultural nanotechnology. Delving into the evolutionary history and specialized adaptations of cyanobacteria, this paper highlights their pivotal role in fixing atmospheric nitrogen, which is crucial for ecosystem productivity. The review discusses the unique characteristics of metal nanoparticles and their emerging applications in agriculture, including improved nutrient delivery, stress tolerance, and disease resistance. It delves into the complex mechanisms of nanoparticle entry into plant cells, intracellular transport, and localization, uncovering the impact on root-shoot translocation and systemic distribution. Furthermore, the paper elucidates cellular responses to nanoparticle exposure, emphasizing oxidative stress, signaling pathways, and enhanced nutrient uptake. The potential of metal nanoparticles as carriers of essential nutrients and their implications for nutrient-use efficiency and crop yield are also explored. Insights into the modulation of plant stress responses, disease resistance, and phytoremediation strategies demonstrate the multifaceted benefits of nanoparticles in agriculture. Current trends, prospects, and challenges in agricultural nanotechnology are discussed, underscoring the need for responsible and safe nanoparticle utilization. By harnessing the power of nitrogen-fixing cyanobacteria and leveraging the unique attributes of nanoparticles, this review paves the way for innovative, sustainable, and efficient agricultural practices. Full article

(This article belongs to the Special Issue Preparation of Innovative Nanomaterials for Water/Air Purification)

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27 pages, 5922 KiB

Open AccessReview

Adsorption and Photocatalytic Degradation of Pesticides into Nanocomposites: A Review

by Franciele S. Bruckmann, Carlos Schnorr, Leandro R. Oviedo, Salah Knani, Luis F. O. Silva, William L. Silva, Guilherme L. Dotto and Cristiano R. Bohn Rhoden

Molecules 2022, 27(19), 6261; https://doi.org/10.3390/molecules27196261 - 23 Sep 2022

Cited by 38 | Viewed by 3644

Abstract

The extensive use of pesticides in agriculture has significantly impacted the environment and human health, as these pollutants are inadequately disposed of into water bodies. In addition, pesticides can cause adverse effects on humans and aquatic animals due to their incomplete removal from [...] Read more.

The extensive use of pesticides in agriculture has significantly impacted the environment and human health, as these pollutants are inadequately disposed of into water bodies. In addition, pesticides can cause adverse effects on humans and aquatic animals due to their incomplete removal from the aqueous medium by conventional wastewater treatments. Therefore, processes such as heterogeneous photocatalysis and adsorption by nanocomposites have received special attention in the scientific community due to their unique properties and ability to degrade and remove several organic pollutants, including pesticides. This report reviews the use of nanocomposites in pesticide adsorption and photocatalytic degradation from aqueous solutions. A bibliographic search was performed using the ScienceDirect, American Chemical Society (ACS), and Royal Society of Chemistry (RSC) indexes, using Boolean logic and the following descriptors: “pesticide degradation” AND “photocatalysis” AND “nanocomposites”; “nanocomposites” AND “pesticides” AND “adsorption”. The search was limited to research article documents in the last ten years (from January 2012 to June 2022). The results made it possible to verify that the most dangerous pesticides are not the most commonly degraded/removed from wastewater. At the same time, the potential of the supported nanocatalysts and nanoadsorbents in the decontamination of wastewater-containing pesticides is confirmed once they present reduced bandgap energy, which occurs over a wide range of wavelengths. Moreover, due to the great affinity of the supported nanocatalysts with pesticides, better charge separation, high removal, and degradation values are reported for these organic compounds. Thus, the class of the nanocomposites investigated in this work, magnetic or not, can be characterized as suitable nanomaterials with potential and unique properties useful in heterogeneous photocatalysts and the adsorption of pesticides. Full article

(This article belongs to the Special Issue Preparation of Innovative Nanomaterials for Water/Air Purification)

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