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Article

Two-Dimensional Silver Bismuth Oxide/Bismuth Molybdate Z-Scheme Heterojunctions with Rich Oxygen Vacancies for Improved Pollutant Degradation and Bacterial Inactivation

by
Yanhong Wang
1,2,
Huijie Zhu
1,2,*,
Pengli He
1,2,
Mingyu Li
1,2,
Yinhuan Cao
3,
Yanqiang Du
1,2,
Yun Wen
1,2,
Yixiang Zhao
1,
Xiaowen Liu
1 and
Yonglong Song
1
1
Henan International Joint Laboratory of New Civil Engineering Structure, School of Intelligent Construction and Civil Engineering, Luoyang Institute of Science and Technology, Luoyang 471023, China
2
Henan Engineering Research Center of Water Quality Safety in the Middle-lower Yellow River, Henan Green Technology Innovation Demonstration Base, Luoyang 471023, China
3
School of Urban Planning and Municipal Engineering, Xi’an Polytechnic University, Xi’an 710048, China
*
Author to whom correspondence should be addressed.
Crystals 2025, 15(4), 318; https://doi.org/10.3390/cryst15040318
Submission received: 10 March 2025 / Revised: 23 March 2025 / Accepted: 25 March 2025 / Published: 27 March 2025
(This article belongs to the Section Inorganic Crystalline Materials)
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Abstract

:
The effective removal of organic pollutants and bacteria are of great significance considering the hazards to the environment and human health. The two-dimensional AgBiO3/Bi2MoO6 heterojunction with rich oxygen vacancies was successfully fabricated via a hydrothermal method and systematically characterized by various analytical techniques. The photocatalytic experimental results revealed that the addition of AgBiO3 improved the photocatalytic performance of Bi2MoO6, and the AgBiO3/Bi2MoO6-10 heterojunction possessed the best degradation effect toward RhB (72%) within 100 min, with 1.38 and 1.44 times higher activity than pure Bi2MoO6 and AgBiO3, respectively. The bacteria were completely inactivated within 90 min by AgBiO3/Bi2MoO6-10 heterojunction. The reason for the enhancement of photocatalytic activity was the synergistic effect between AgBiO3 and Bi2MoO6. The constructed Z-scheme heterojunction with oxygen vacancies improved the separation efficiency of photo-induced electrons and holes and broadened the range of visible-light absorption. The trapping experiments and ESR indicated that superoxide radical and holes were the main reactive species.

1. Introduction

With the continuous progress of society, the rapid development of industry has brought enormous challenges to the environment. Various dyes originated from industrial and domestic wastewater could not be naturally degraded, which could be removed through physical or chemical methods [1,2,3]. Currently, the photocatalytic degradation had some advantages, such as the simplicity of method, easy availability of materials, and rapid pollution control, which was the focus of research [4,5]. Photocatalytic technology could effectively utilize solar energy to catalyze large pollutant molecules into non-toxic and harmless substances, which could also catalyze hydrogen production to solve the problem of fossil fuel shortage [6,7]. Admittedly, the main commercial photocatalyst was TiO2, but the disadvantages of TiO2 were particularly obvious. The band-gap width of TiO2 was 3.2 eV, which could only be excited in the ultraviolet region, limiting the development of TiO2 [8]. Researchers have developed Bi-based photocatalysts [9], Ag-based photocatalysts [10], and g-C3N4 photocatalysts [11]. It was particularly crucial to find a photocatalyst that could complete the reaction under visible-light irradiation.
Bi2MoO6, one of the many novel photocatalysts, had a perovskite-like structure composed of alternating stacking of [Bi2O2]2+ and [MoO4]2−. It possessed a relatively narrow band gap (2.5–2.8 eV) and moderate band positions, which was typical of an Aurivillius compound [12,13,14]. This special layered structure could facilitate charge transfer, resulting in better photocatalytic performance. It had a wide range of applications in fields such as organic pollutant degradation, water splitting for hydrogen production, and CO2 reduction because it was non-toxic and harmless [15,16,17]. However, Bi2MoO6 also had certain limitations in insufficient separation of photo-generated electrons and holes due to factors such as imbalanced positions and widths of the conduction band (CB) and valence band (VB). In order to compensate for defects and improve photocatalytic performance, the construction of heterogeneous structure was proved to enhance the catalytic effect of photocatalysts, attributed to the enhanced utilization of sunlight, and the improved stability of photocatalysts [18,19,20]. In recent years, constructing heterojunction photocatalysts has become one of the effective methods for adjusting the transfer pathway of electrons and promoting rapid separation of photo-induced electron-hole pairs at heterojunction interfaces [21,22,23]. For example, Yang fabricated a direct Z-scheme Bi2MoO6/CoWO4 heterostructure for norfloxacin degradation. The experimental results indicated that the BMC-30 showed the optimum photodegradation efficiency of norfloxacin, reaching 97.1% within 60 min illumination. The apparent rate constant was 0.0588 min−1, which was 2.42 and 17.80 times than those of Bi2MoO6 and the CoWO4, respectively. The improved photocatalytic performance was principally due to the efficient utilization of electrons and holes ascribed to the construction of a direct Z-scheme heterostructure [24]. Su synthesized a direct Z-scheme Bi2MoO6/UiO-66-NH2 heterojunction, which was evaluated with typical fluoroquinolone antibiotics, ofloxacin, and ciprofloxacin under visible-light illumination. The OFL removal efficiencies using BUN-100 heterojunction was the highest (100.0%) within 90 min of illumination, which was attributed to the Z-scheme charge transfer [25].
Ag-based semiconductors have become candidate materials for photocatalytic technology due to their unique crystal structure. AgBiO3, as a typical Ag-based material, has attracted much more attention due to controllable release of lattice oxygen, which generated a large amount of reactive oxygen species (ROS) in the absence of light [26,27]. AgBiO3 was a black crystalline material with a narrow band-gap width, which had the characteristics of high stability, excellent photocatalytic performance, high visible-light utilization and strong redox properties. Compared with traditional photocatalysts, the photocatalytic activity of AgBiO3 were relatively outstanding, which could effectively remove organic pollutants in water. However, AgBiO3 was prone to photo-corrosion under visible-light illumination and had a low separating efficiency for photo-generated carriers, which would reduce the stability and catalytic activity in degrading pollutants. In response to the series of problems of AgBiO3, it could be solved to couple with other semiconductor materials, improve the separation efficiency of photo-generated carrier and enhance photocatalytic activity [28,29]. Lu prepared efficient S-scheme heterojunction photocatalysts through in situ growth of AgBiO3 on BiOBr. The optimized AgBiO3/BiOBr heterojunction possessed excellent visible-light photocatalytic degradation efficiency (83%) for ciprofloxacin after 120 min, with 1.46 and 4.15 times higher activity than pure AgBiO3 and BiOBr, respectively [30]. Chen successfully prepared binary BiO2-x/AgBiO3 heterojunction through a two-step hydrothermal process. The activity of optimal AB30 was 8.9 and 2.8 times higher than that of pure BiO2-x and AgBiO3 towards MO. The enhanced photocatalytic activity was due to heterojunction effect, improving the effective separation and transfer of photo-generated charge carriers [31].
In this paper, AgBiO3/Bi2MoO6 heterojunction with oxygen vacancies was prepared by hydrothermal method. The photocatalytic activities of photocatalysts towards RhB and bacteria were investigated. The effects of photocatalytic degradation process of RhB such as the concentration of RhB and impurity ions were studied.

2. Experimental

2.1. Chemicals

Bismuth nitrate pentahydrate (Bi(NO3)3·5H2O), silver nitrate (AgNO3), Ammonium molybdate tetrahydrate ((NH4)6Mo7O24·4H2O), sodium bismuthate (NaBiO3), and absolute alcohol (CH3CH2OH) were purchased from Sinopharm Chemical Regent (Shanghai, China). All chemicals were of analytical reagent (AR) grade. Deionized water was used in all experiments.

2.2. Synthesis of Bi2MoO6

The Bi2MoO6 with oxygen vacancies were synthesized by simple hydrothermal method. Typically, 1 mol Bi(NO3)3·5H2O and 0.14 mol (NH4)6Mo7O24·4H2O were dissolved in 30 mL dilute nitric acid solution and 30 mL deionized water, respectively. Then, the above solutions were mixed and stirring continuously for 40 min. The pH was adjusted to 9 with dilute ammonia water, and then the solution continued stirring for another 30 min. The solution was transferred to a 100 mL Teflon-lined autoclave and kept at 180 °C for 12 h. The synthetic samples were washed with deionized water and absolute alcohol, dried in an oven at 100 °C for 12 h. The as-prepared Bi2MoO6 was annealed at 400 °C for 12 h in a N2 atmosphere, and the obtained samples was labeled as Bi2MoO6-OVs.

2.3. Synthesis of AgBiO3/Bi2MoO6

0.6 g Bi2MoO6-OVs was dissolved into 50 mL of DI water, which was sonicated for 30 min. Subsequently, 0.12 g AgNO3 was added into the above solution and sonicated for 40 min. Then, 0.24 g NaBiO3 was dissolved into the solution, stirring for 30 min at room temperature. Afterwards, the mixture solution was centrifuged at 5000 rpm. The final product was washed with deionized water and absolute alcohol, then dried in an oven at 100 °C for 12 h. The mass ratio of AgBiO3 and Bi2MoO6-OVs were 5%, 10%, and 15%, referring to ABM-5, ABM-10, ABM-15. Pristine AgBiO3 was prepared through similar procedures without adding Bi2MoO6-OVs.

2.4. Characterization

A Bruker D8-Advance X-ray diffractometer using Cu Kα radiation (λ = 0.15406 Å) at 40 kV and 40 mA and a scanning rate of 10°/min was served as record power XRD data. The morphology were investigated by field emission scanning electron microscopy (FESEM, SU8010) and transmission electron microscopy (TEM, JEM-2100). Photoluminescence (PL) spectra of the as-prepared samples were observed with a fluorescence spectrometer (Hitachi F-4500). The electron spin resonance (ESR) spectra were measured on a Bruker ER200-SRC spectrometer using trap reagent DMPO in methanol and water.

2.5. Evaluation of Simulated Solar Driven Photocatalytic Performance

The photocatalytic degradation experiment of AgBiO3/Bi2MoO6 heterojunction was conducted at room temperature using a 350 W xenon lamp with a UV-cutoff filter (λ > 420 nm) as the light source to evaluate the degradation of RhB. Typically, 40 mL aqueous solution containing RhB (10 mg/L) and catalysts (1 g/L) were agitated for 30 min in the dark to attain adsorption–desorption equilibrium. Then, the light was turned on, 3 mL of solution was withdrawn at a scheduled interval, and then centrifugation occurred. The concentrations of RhB were measured using a UV–vis spectrophotometer (UV-2450).

2.6. Bacterial Inactivation Test

The antimicrobial experiments were carried out with Gramnegative Escherichia coli (E. coli, ATCC®25922). The as-prepared samples were treated with ultrasound for 3 h and subsequently disinfected at 120 °C for 40 min. The sample (5 mg·L−1) was suspended in a 10 mL E. coli culture medium and illuminated under a 350 W xenon lamp. During photocatalytic antimicrobial experiments, 1 mL suspensions were withdrawn at a scheduled interval and solutions were first serially diluted and coated again on a solid LB medium.

3. Results and Discussion

3.1. Physicochemical Properties

The X-ray diffraction patterns of different samples were trialed to investigate the composition of materials. As shown in Figure 1a, pristine Bi2MoO6 exhibited distinct diffraction peaks at 2θ = 28.3°, 32.5°, 33.1°, 36.0°, 47.1°, 55.4°, and 56.3°, corresponding to (131), (200), (060), (151), (260), (331), and (191) of Bi2MoO6, respectively (JCPDS No. 21-0102). After annealed in N2 atmosphere, the Bi2MoO6 with oxygen vacancies showed no significant changes in peaks except for the diffraction peak on the (060) plane, which might be due to the influence of oxygen defects [15]. This was confirmed by EPR test (Figure 1b). Due to the electron capture of oxygen vacancies, a signal at g = 2.004 could validate that oxygen vacancies were in the presence of Bi2MoO6-OVs, thus improving the photocatalytic activity [32]. On the other hand, AgBiO3 exhibited characteristic diffraction peaks at 31.7° and 35.9°, which were consistent with the diffraction peaks of AgBiO3 (JCPDS No. 89-9072). The characteristic diffraction peaks of AgBiO3/Bi2MoO6 heterojunction with oxygen vacancies were similar to those of Bi2MoO6, indicating that the crystal structure of AgBiO3/Bi2MoO6 heterojunction was almost unaffected by AgBiO3. Because of the low and dispersed content of AgBiO3, no characteristic peak of AgBiO3 was observed in the AgBiO3/Bi2MoO6 heterojunction. No other impurity peaks were found in the product, indicating that the high purity AgBiO3/Bi2MoO6 heterojunction was composed.
The SEM images of AgBiO3, Bi2MoO6, and AgBiO3/Bi2MoO6 heterojunction were plainly observed in Figure 2. The pristine AgBiO3 showed a flower-like structure composed of thin nanosheets with a diameter of around 1–2 µm (Figure 2a). In Figure 2b, the pure Bi2MoO6 exhibited a smooth sheet-like structure. The formed AgBiO3/Bi2MoO6 heterojunction was composed of flower-like AgBiO3 and sheet-like Bi2MoO6, and the flower-like AgBiO3 dispersed in the sheet-like Bi2MoO6 (Figure 2c).
The ABM-10 heterojunction was further investigated by TEM and HRTEM. As revealed in Figure 3a, sheet-like AgBiO3 and Bi2MoO6 were both clearly observed with a diameter of around 1–3 µm and they interlocked with each other in the ABM-10 heterojunction. In Figure 3b, lattice spacing of 0.315 nm and 0.310 nm corresponded to the (131) plane of Bi2MoO6 and the (104) plane of AgBiO3, respectively, which further confirmed the formation of AgBiO3/Bi2MoO6 heterojunction. Simultaneously, the elements Bi, O, Mo, and Ag were all probed on the surface of AgBiO3/Bi2MoO6 heterojunction (Figure 4).

3.2. Photocatalytic Activity

The wastewater originated from the printing and dyeing industry was not only difficult to treat but also caused serious environmental pollution that endangered human health. Among them, Rhodamine B (RhB) was the most common type, which was used as a target pollutant to evaluate the photocatalytic performance of the as-prepared samples. As shown in Figure 5a, the degradation efficiencies of pure Bi2MoO6 and AgBiO3 towards RhB were 52% and 50%, respectively, under visible-light irradiation for 100 min. The degradation efficiency of RhB by Bi2MoO6-OVs was 57%, attributed to the introduction of oxygen vacancies that could reduce the band-gap width and promote the separation and transfer of photo-generated electrons and holes, enhancing photocatalytic activity, while the photocatalytic activity of ABM-10 heterojunction was optimum with a degradation efficiency of 72%. Evidently, as the content of AgBiO3 increased, the degradation efficiency of the catalysts first increased and then decreased, indicating that AgBiO3 played an important role in the photocatalytic degradation process, which was mainly due to the fact that AgBiO3 facilitated charge transfer and suppressed the recombination of photo-induced electron and hole pairs. However, excessive AgBiO3 might form a new recombination center of photo-induced electrons and holes, reducing photocatalytic activity. As shown in Figure 5b, the control blank revealed slight degradation of RhB in absence of the catalysts and the experiments authentically reached adsorption–desorption equilibria in the dark for 30 min prior to irradiation. By comparison, the mechanical mixture of Bi2MoO6-OVs and 10 wt% AgBiO3 was also tested, and the experiments result showed that the photocatalytic activity of mechanical mixture was inferior to that of ABM-10 heterojunction, indicating the poor interfacial contact between AgBiO3 and Bi2MoO6-OVs in the mechanical mixture. In Figure 5c, the reaction kinetics of RhB degradation were modeled by pseudo-first-order kinetics model: ln (Co/C) = kt, where Co and C were, respectively, the initial and instant concentrations at reaction time t, and k was the rate constant. The rate constant of ABM-10 heterojunction was 0.0094 min−1, while the k of ABM-5, ABM-15, AgBiO3, Bi2MoO6, and Bi2MoO6-OVs were 0.0085, 0.0081, 0.0041, 0.0069, and 0.0072 min−1, respectively. The k of ABM-10 heterojunction was 1.11, 1.16, 2.29, 1.36 and 1.31 times higher than that of ABM-5, ABM-15, AgBiO3, Bi2MoO6 and Bi2MoO6-OVs. Figure 5d showed the absorbance spectrum of RhB degraded by ABM-10 heterojunction. Clearly, the characteristic peak of RhB gradually decreased at 570 nm, indicating that RhB gradually degraded.
In practical applications, the content of photocatalysts was a key factor in affecting degradation efficiency. In Figure 6a, when the concentration of photocatalyst increased from 10 mg to 40 mg, the degradation efficiency of RhB was significantly improved, mainly due to the increased photocatalyst which could produce more active species. Afterwards, the effect of different concentrations of RhB on the photocatalytic degradation process was investigated in Figure 6b. It was found that, when the initial concentration of RhB increased from 5 mg/L to 20 mg/L, the degradation efficiency of RhB decreased from 80% to 35%, indicating that the photocatalytic performance of the catalysts decreased with the increase in RhB concentration. This might be attributed to the fact that the higher concentration of RhB hindered the visible-light absorption of the catalysts and consumed quickly the active species generated by the catalysts. As shown in Figure 6c, the photocatalytic performance of catalysts was explored through adding different ions (Cu2+, SO42−, PO43−, 1 mmol/L) into the degradation process of RhB. When PO43− was added into the solution, the degradation process was significantly suppressed in the presence of ABM-10 heterojunction, mainly due to the fact that PO43− easily reacted with holes, thereby reducing the photocatalytic efficiency. Subsequently, the degradation efficiency of RhB decreased with the introduction of Cu2+, which could be explained by the fact that Cu2+ could combine with RhB or intermediates to form stable metal complexes, inhibiting the degradation process [33]. In addition, the photocatalytic degradation of RhB was restrained by SO42−, which might be attributed to the fact that •OH was consumed by SO42− to generate •SO4− [34,35].
As shown in Figure 7a–d, Carbamazepine, Norfloxacin, Ofloxacin and RhB were used to investigate the influence of coexisting organic pollutants. The concentrations of the organic interferents were 10 mg/L. Figure 7b showed that the removal efficiency of RhB decreased from 72% to 60% after introducing carbamazepine. When the ofloxacin and norfloxacin were added into RhB, respectively, the removal efficiency of ABM-10 towards RhB decreased to 18% and 16%, indicating that the other organic pollutants extremely affected the removal efficiency, which might be attributed to competitive interactions between organic contaminants for active species (Figure 7c,d) [36].
In Figure 8a, the degradation efficiencies of ABM-10 towards RhB, CIP, MB, MO, LR5B, BPA and phenol were 72%, 70%, 66%, 63%, 55%, 41%, and 37%, respectively. These different photocatalytic activities of ABM-10 were attributed to diverse adsorption characteristics and molecular architectures of these organic contaminants. The photocatalytic stability of the as-prepared sample was momentous for practical application. To investigate the stability of ABM-10 heterojunction, the photocatalytic degradation of RhB was carried out across four cycles. As shown in Figure 8b, after four successive cycles, ABM-10 heterojunction still showed excellent activity for RhB degradation.
The antibacterial results of the AB-10 heterojunction were shown in Figure 9. Under dark conditions, the AB-10 heterojunction did not exhibit significant antibacterial activity (Figure 9a). Under visible-light irradiation, the ABM-10 heterojunction had a significant antibacterial effect on E. coli, completely inhibiting bacteria within 90 min (Figure 9b–d). The reason might be that the ABM-10 heterojunction generated a highly oxidizing active species under visible-light irradiation, which killed bacteria.

3.3. Photocatalytic Mechanism

PL spectroscopy was used to investigate the recombination efficiency of photo-induced electrons and holes, and 320 nm was served as the excitation wavelength. In general, a weaker PL intensity reflects a lower recombination probability. As shown in Figure 10, the PL intensity of Bi2MoO6-OVs was lower than that of Bi2MoO6, due to the introduction of oxygen vacancies that could promote the separation and transfer of photo-induced electrons and holes. Furthermore, the PL intensity of ABM-10 heterojunction was lower than that of Bi2MoO6 and Bi2MoO6-OVs, indicating that the recombination of the photo-induced carriers of the heterojunction was effectively suppressed, which was attributed to the formation of ABM-10 heterojunction.
To study photocatalytic mechanism of ABM-10 heterojunction, isopropanol (IPA), disodium ethylenediaminetetraacetate (EDTA-2Na), and benzoquinone (BQ) were added to capture hydroxyl radicals (•OH), holes (h+), and superoxide radicals (•O2−), respectively [36]. The dosage of these scavengers was 2 mM. As shown in Figure 11a, after the addition of EDTA-2Na and benzoquinone in the reaction, the degradation efficiencies of RhB were only 14% and 19%, respectively, suggesting that the photodegradation process was severely inhibited. While adding IPA, the degradation efficiency of RhB was 56%, indicating that the degradation process was slightly inhibited. The results indicated that •O2− and h+ were the main active species in photocatalytic reaction, while •OH played a role in assisting degradation. Moreover, ESR experiment was carried out to detect •O2− and•OH during photocatalytic processes. As revealed in Figure 11b,c, no characteristic signal could be observed for both DMPO-•OH and DMPO-•O2− in dark. While the signals of DMPO-•OH and DMPO-•O2− were observed for ABM-10 heterojunction after 10 min, further confirming that •OH and •O2− radicals were present in the photocatalytic process.
Based on the above results, a possible photocatalytic mechanism of ABM-10 heterojunction could be supposed (Figure 12). As shown in Figure 12a, AgBiO3 and Bi2MoO6 generated photo-induced electron-hole pairs on the surface under visible-light irradiation. Traditionally, the photo-generated electrons of AgBiO3 would transfer to the CB of Bi2MoO6. Meanwhile, the photo-generated holes of Bi2MoO6 would transfer to the VB of AgBiO3 [24]. However, the CB position of Bi2MoO6 (−0.21 eV) was more positive than the standard redox potential of E (O2/•O2−) (−0.33 eV vs. NHE) [37], which resulted in the photo-induced electrons in the CB of Bi2MoO6 not reacting with O2 to produce •O2−, which is inconsistent with the capture experiment. Evidently, the trapping experiment and ESR analysis have demonstrated that •O2−, h+ and •OH were present in the degradation process. Accordingly, the Z-scheme charge transfer mechanism was supposed. In Figure 12b, the CB position of AgBiO3 (−0.68 eV) was more negative than the standard redox potential of E (O2/•O2−) (−0.33 eV vs. NHE), which led to the photo-induced electrons on the conduction band of AgBiO3 to reduce O2 to •O2−. In addition, the VB position of Bi2MoO6 (+2.57 eV) was more positive than the standard redox potential of E (•OH/OH−) (+1.99 eV vs. NHE) [38,39], which meant that H2O could be oxidized to generate •OH. Therefore, the Z-scheme charge transfer mechanism was more reasonable for the RhB degradation process.

4. Conclusions

In summary, a novel two-dimensional AgBiO3/Bi2MoO6 heterojunction was prepared by the simple solvothermal method. The as-prepared AgBiO3/Bi2MoO6 heterojunction was composed of flower-like AgBiO3 and sheet-like Bi2MoO6. The ABM-10 heterojunction revealed the best degradation efficiency for RhB under visible-light irradiation for 100 min, reaching 72%, which was 1.38 and 1.44 times higher activity than pure Bi2MoO6 and AgBiO3, respectively. Meanwhile, the bacteria were inactivated within 90 min in the presence of the ABM-10 heterojunction. The enhanced photocatalytic activity was due to synergistic effects of heterojunction and oxygen vacancies. Moreover, the ABM-10 heterojunction showed good photocatalytic performance for several other polluted wastewater (CIP: 70%, MB: 66%, MO: 63%, LR5B:55%, BPA: 41% and phenol: 37%). The experimental results of coexisting pollutants indicated that the degradation efficiency of RhB decreased due to the competitive interaction between organic pollutants. A possible Z-scheme photocatalytic mechanism has been proposed, attributed to the result of trapping experiments and ESR.

Author Contributions

Y.W. (Yanhong Wang): Conceptualization, Methodology, Software, Investigation, Formal analysis, Writing—original draft. H.Z.: Software, Resources, Investigation, Writing—review and editing. P.H.: Conceptualization, Software. M.L.: Visualization, Funding acquisition. Y.C.: Formal analysis, Data curation. Y.D.: Investigation, Data curation, Funding acquisition. Y.W. (Yun Wen): Methodology, Software. Y.Z.: Investigation. X.L.: Software, Investigation. Y.S.: Investigation, Data curation. All authors have read and agreed to the published version of the manuscript.

Funding

This research was funded by National Nature Science Foundation of China (Grant No. 42402291), the Key Scientific Research Project of Colleges and Universities in Henan Province (Grant No. 23B560011), Scientific and Technological Project in Henan Province (Grant No. 232103810103), Heluo Youth Talent Support Project (Grant No. 2023HLTJ04).

Data Availability Statement

All data, models, and code generated or used during the study appear in the submitted article.

Acknowledgments

This work was supported by Henan Engineering Research Center of Water Quality Safety in the Middle-lower Yellow River and Henan Green Technology Innovation Demonstration Base.

Conflicts of Interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

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Figure 1. (a) XRD patterns of the standard diffraction card of as-synthesized samples, (b) EPR spectra of Bi2MoO6 and Bi2MoO6-OVs.
Figure 1. (a) XRD patterns of the standard diffraction card of as-synthesized samples, (b) EPR spectra of Bi2MoO6 and Bi2MoO6-OVs.
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Figure 2. SEM of (a) AgBiO3, (b) Bi2MoO6 and (c) ABM-10 heterojunction.
Figure 2. SEM of (a) AgBiO3, (b) Bi2MoO6 and (c) ABM-10 heterojunction.
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Figure 3. (a) The TEM and (b) HRTEM image of ABM-10 heterojunction.
Figure 3. (a) The TEM and (b) HRTEM image of ABM-10 heterojunction.
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Figure 4. EDS elemental mapping of ABM-10 heterojunction (a–g).
Figure 4. EDS elemental mapping of ABM-10 heterojunction (a–g).
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Figure 5. (a,b) Degradation efficiencies, (c) kinetic curves of RhB and (d) time−dependent absorption spectra of RhB with the as-prepared photocatalysts.
Figure 5. (a,b) Degradation efficiencies, (c) kinetic curves of RhB and (d) time−dependent absorption spectra of RhB with the as-prepared photocatalysts.
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Figure 6. Degradation efficiencies of the RhB solution by (a) various ABM−10 dosage ([RhB] = 10 mg/L), (b) various concentration of RhB ([ABM−10] = 40 mg) and (c) under different concentration of PO43−, SO42−, and Cu2+.
Figure 6. Degradation efficiencies of the RhB solution by (a) various ABM−10 dosage ([RhB] = 10 mg/L), (b) various concentration of RhB ([ABM−10] = 40 mg) and (c) under different concentration of PO43−, SO42−, and Cu2+.
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Figure 7. (a) Degradation efficiencies of RhB coexisting other pollutants, (b–d) Time−dependent absorption spectra of organic substances degradation.
Figure 7. (a) Degradation efficiencies of RhB coexisting other pollutants, (b–d) Time−dependent absorption spectra of organic substances degradation.
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Figure 8. (a) Degradation efficiencies of ABM-10 towards different organic contaminants, (b) Cycle runs of ABM-10 for the degradation of RhB.
Figure 8. (a) Degradation efficiencies of ABM-10 towards different organic contaminants, (b) Cycle runs of ABM-10 for the degradation of RhB.
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Crystals 15 00318 g009
Figure 9. The surviving culture growth of E. coli incubated with ABM-10 heterojunction at fixed time intervals of 0–90 (a–d) min under visible-light irradiation.
Figure 9. The surviving culture growth of E. coli incubated with ABM-10 heterojunction at fixed time intervals of 0–90 (a–d) min under visible-light irradiation.
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Figure 10. PL spectra of the as-prepared samples.
Figure 10. PL spectra of the as-prepared samples.
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Figure 11. (a) Trapping experiments of active species during photodegradation of RhB in the presence of ABM-10 heterojunction, (b) DMPO-•O2−, and (c) DMPO-•OH adducts on ABM-10 heterojunction.
Figure 11. (a) Trapping experiments of active species during photodegradation of RhB in the presence of ABM-10 heterojunction, (b) DMPO-•O2−, and (c) DMPO-•OH adducts on ABM-10 heterojunction.
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Figure 12. Proposed charge transfer and photocatalytic mechanisms (a,b) for removal of RhB over the ABM−10 heterojunction.
Figure 12. Proposed charge transfer and photocatalytic mechanisms (a,b) for removal of RhB over the ABM−10 heterojunction.
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MDPI and ACS Style

Wang, Y.; Zhu, H.; He, P.; Li, M.; Cao, Y.; Du, Y.; Wen, Y.; Zhao, Y.; Liu, X.; Song, Y. Two-Dimensional Silver Bismuth Oxide/Bismuth Molybdate Z-Scheme Heterojunctions with Rich Oxygen Vacancies for Improved Pollutant Degradation and Bacterial Inactivation. Crystals 2025, 15, 318. https://doi.org/10.3390/cryst15040318

AMA Style

Wang Y, Zhu H, He P, Li M, Cao Y, Du Y, Wen Y, Zhao Y, Liu X, Song Y. Two-Dimensional Silver Bismuth Oxide/Bismuth Molybdate Z-Scheme Heterojunctions with Rich Oxygen Vacancies for Improved Pollutant Degradation and Bacterial Inactivation. Crystals. 2025; 15(4):318. https://doi.org/10.3390/cryst15040318

Chicago/Turabian Style

Wang, Yanhong, Huijie Zhu, Pengli He, Mingyu Li, Yinhuan Cao, Yanqiang Du, Yun Wen, Yixiang Zhao, Xiaowen Liu, and Yonglong Song. 2025. "Two-Dimensional Silver Bismuth Oxide/Bismuth Molybdate Z-Scheme Heterojunctions with Rich Oxygen Vacancies for Improved Pollutant Degradation and Bacterial Inactivation" Crystals 15, no. 4: 318. https://doi.org/10.3390/cryst15040318

APA Style

Wang, Y., Zhu, H., He, P., Li, M., Cao, Y., Du, Y., Wen, Y., Zhao, Y., Liu, X., & Song, Y. (2025). Two-Dimensional Silver Bismuth Oxide/Bismuth Molybdate Z-Scheme Heterojunctions with Rich Oxygen Vacancies for Improved Pollutant Degradation and Bacterial Inactivation. Crystals, 15(4), 318. https://doi.org/10.3390/cryst15040318

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