Synergistic Effects of Ag Nanoparticles/BiV1-xMoxO4 with Enhanced Photocatalytic Activity

Nanoscale Research Letters, Nov 2017

In recent years, BiVO4 has drawn much attention as a novel photocatalyst given its excellent ability to absorb visible light. This work reports the development of Ag-modified BiV1-xMoxO4 composites through a facile hydrothermal synthesis with the subsequent photoinduced reduction of Ag+ at almost neutral pH conditions. Metallic Ag nanoparticles were deposited on the (040) facet of Mo-doped BiVO4 powders. The crystal structure and morphology of the as-prepared samples were studied by XRD and SEM analyses. Moreover, the photocatalytic performance of BiVO4, Ag/BiVO4, and Ag-modified BiV1-xMoxO4 were evaluated by the degradation of rhodamine B (RhB). The Ag/BiV0.9925Mo0.0075O4 composite exhibited the most efficient photocatalytic performance. The present work provides greater insight into the application of BiVO4 in the field of photocatalysis.

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Synergistic Effects of Ag Nanoparticles/BiV1-xMoxO4 with Enhanced Photocatalytic Activity

Yu et al. Nanoscale Research Letters Synergistic Effects of Ag Nanoparticles/BiV 1- Mo O with Enhanced Photocatalytic x x 4 Activity Mengting Yu 1 Shixiong Zhou 1 Qingguo Meng 0 Haiqin Lv 0 Zhihong Chen 0 2 Yongguang Zhang 2 Mingliang Jin 1 2 Mingzhe Yuan 0 Xin Wang 1 2 Guofu Zhou 1 2 0 Shenyang Institute of Automation, Chinese Academy of Sciences , Guangzhou 511458 , China 1 South China Academy of Advanced Optoelectronics, South China Normal University , Guangzhou, Guangdong Province , China 2 International Academy of Optoelectronics at Zhaoqing, South China Normal University , Guangzhou, Guangdong Province , China In recent years, BiVO4 has drawn much attention as a novel photocatalyst given its excellent ability to absorb visible light. This work reports the development of Ag-modified BiV1-xMoxO4 composites through a facile hydrothermal synthesis with the subsequent photoinduced reduction of Ag+ at almost neutral pH conditions. Metallic Ag nanoparticles were deposited on the (040) facet of Mo-doped BiVO4 powders. The crystal structure and morphology of the as-prepared samples were studied by XRD and SEM analyses. Moreover, the photocatalytic performance of BiVO4, Ag/BiVO4, and Ag-modified BiV1-xMoxO4 were evaluated by the degradation of rhodamine B (RhB). The Ag/BiV0.9925Mo0.0075O4 composite exhibited the most efficient photocatalytic performance. The present work provides greater insight into the application of BiVO4 in the field of photocatalysis. Hydrothermal synthesis; Photocatalytic; Metal doping; Ag/BiV1-xMoxO4 Background Given the increasing environmental pollution and energy crises, the development of efficient and promising solutions to reduce energy shortages and protect the environment is paramount [ 1, 2 ]. Photocatalyst-based semiconductors, such as Bi2WO6 [ 3, 4 ], BiPO4 [ 5, 6 ], Ag3PO4 [ 7, 8 ], and BiVO4 [ 9–13 ], have attracted much attention due to their applications in the degradation of organic pollutants or hydrogen production from water splitting. Nevertheless, most of the existing oxide photocatalysts have very low light-response efficiencies primarily because they only respond to ultraviolet light due to their narrow bandgaps [ 14–16 ]. Additionally, the photoinduced electrons can easily recombine with holes leading to a lower optical performance [ 17, 18 ]. Due to its visible photocatalytic activity, wide bandgap of 2.42 eV, high stability, and non-toxicity, bismuth vanadate (BiVO4) is a promising n-type semiconductor photocatalyst [ 19–21 ]. However, its resulting carrier transfer efficiency is relatively poor, leading to the recombination of photogenerated electrons and holes, which severely limits the photocatalytic performance of BiVO4. Various studies have assessed BiVO4 modifications [ 20, 22–24 ], and substitution or metal doping on BiVO4 has been shown as the most efficient method to change its carrier transport efficiency. Metal element doping introduces new defects or charges in the crystal lattice [25], influencing the motion of electrons and the creation of holes under light irradiation [ 26, 27 ]. Adjustments to the distribution status or changes in the band structures can lead to changes in the activity of semiconductors [28]. For example, Thalluri et al. [ 29 ] introduced hexavalent molybdenum (Mo) at an almost neutral pH to substitute V while preserving the atomic ratio of fBiVO4, leading to the formation of a good crystal structure and considerable photocatalytic activity for water oxidation. Mo has a higher valence than V and therefore strengthens the n-type characteristics of the material [ 30 ]. Additionally, the photocatalytic activity of BiVO4 is highly dependent on its various crystal facets. Recent studies on the deposition of noble metals, such as Ag, Cu, and Au, on the different facets of BiVO4 have demonstrated good photocatalytic activity [ 31–33 ]. Li et al. [ 34 ] produced an Ag/BiVO4 composite through the hydrothermal synthesis and photoreduction of Ag deposited on the (040) crystal facets of BiVO4, leading to an enhanced photoelectrochemical performance, as indicated by the fast separation of the electron–hole pairs. In the present study, we build on the facile hydrothermal synthesis approach of Li et al. [ 29 ] to obtain BiV0.9925Mo0.0075O4 in weakly alkaline conditions, coupled with photoreduction deposition of Ag nanoparticles on the (040) facets of the as-produced substrate materials. Ag/BiV0.9925Mo0.0075O4 composite photocatalysts were successfully synthesized and showed enhanced photocatalytic degradation of rhodamine B (RhB) under xenon lamp irradiation (λ > 420 nm) compared to the non-composite Ag-deposited or Mo-doped BiVO4 materials. Herein, we report the preparation, characterization, and photocatalytic activity of BiVO4, Ag/BiVO4, BiV1xMoxO4, and Ag/BiV1-xMoxO4 composites. Experimental Synthesis of BiVO4 and BiV1-xMoxO4 Powders Bismuth nitrate pentahydrate (Bi(NO3)3·5H2O, analytical grade), ammonium metavanadate (NH4VO3, analytical grade), ammonium carbonate, and ammonium molybdate ((NH4)2MoO4) were obtained from Sigma–Aldrich and used as received, without any further purification. All other chemicals used in the experiments were also of analytical grade, and deionized water was used for the preparation of the solutions. In a typical process, 3.7 mmol of Bi(NO3)3·5H2O, 3.7 mmol of NH4VO3, and 12 mmol of (NH4)2CO3 were dissolved in 75 mL of 1 M HNO3 and stirred for approximately 30 min at room temperature until a clear solution was obtained. The pH of the mixture was adjusted to pH 8 with NaOH (2 M). The mixture was transferred into a 150-mL Teflon-lined stainless autoclave and heated for 12 h at 180 °C under autogenous pressure in an oven. The precipitate was filtered and washed three times with distilled water followed by ethanol and dried for 12 h at 60 °C in a drying oven. The doped samples were prepared by replacing the equivalent weight of NH4VO3 with different amounts of Mo. Mo precursors were introduced such that a nominal 0.5, 0.75, and 1% atomic substitution of V was achieved. Preparation of Ag/BiVO4 and Ag/BiV1-xMoxO4 Samples BiVO4 (0.50 g) and AgNO3 (0.05 g) were added to a (NH4)2C2O4 (0.8 g L−1, 100 mL) aqueous solution in a 250-mL beaker in an ultrasonic bath until an evenly dispersed solution was formed. The resulting yellow mixture was then irradiated with a Xenon lamp for 30 min under magnetic stirring. The color of the system turned from a vivid yellow to grayish-green, indicating the generation of metallic Ag in the reaction system. The resulting samples were then filtered, washed with DI water, and dried at 60 °C for 12 h to obtain the Ag/BiVO4 and Ag/BiV1-xMoxO4 composites. Photocatalytic Activity Assessment of the photocatalytic activity was performed using the degradation rate of RhB. The experimental system for photodegradation was calibrated at a UV cut-off wavelength below 420 nm, and the irradiation height of the Xenon lamp was close to the height of the 250-mL beaker. In a typical procedure, the as-prepared photocatalyst (0.1 g) was well dispersed in a RhB aqueous solution (150 mL, 10 mg L−1) under ultrasonication in a glass reactor equipped with a cooling water circulator to maintain a reaction system temperature of room temperature. The suspension was stirred for 30 min in the dark to reach the adsorption–desorption equilibrium and was then irradiated for 2 h with a Xenon lamp (300 W) under continuous stirring. A 5-mL aliquot of the suspension was taken every 30 min and centrifuged. The absorption spectrum of the obtained liquid Fig. 1 a XRD patterns of pure BiVO4, Ag/BiVO4, BiV1-xMoxO4, and Ag/ BiV1-xMoxO4. b The corresponding EDX analysis of Ag /BiV0.9925Mo0.0075O4 supernatant was measured in reference to the absorption intensity of RhB at 552 nm. Characterization Techniques The morphologies of the pure BiVO4 and the decorated composites were investigated by field emission scanning electron microscopy (FESEM, S4800) and transmission electron microscopy (TEM; JEM-2100F, JEOL). Elemental analysis was performed by X-ray photoelectron spectroscopy (XPS; VGESCA-LAB MKII) with a nonmonochromatic Mg Kα X-ray source. The crystalline phase of the samples was determined by X-ray diffraction (XRD; Bruker D8) with Cu Kα radiation. Inductively coupled plasma (ICP) was employed to analyze the elemental composition of the samples. Additionally, UV–vis diffuse reflectance spectrum measurements were performed using a Shimadzu spectrophotometer (UV-2450) to evaluate the bandgap energy of BiVO4, Ag/BiVO4, BiV1-xMoxO4, and Ag/BiV1-xMoxO4 over a wavelength range of 360–800 nm. Results and Discussion The crystallographic structure and phase of the prepared composites were characterized by XRD analysis (Fig. 1a). The sharp diffraction peaks observed in the as-prepared BiVO4 were assigned to the conventional BiVO4 phase since they were in good agreement with the standard (JCPDS) card no. 14-0688. According to the peak splitting observed at 18.7° and 30.5°, which indicate the (110) and (040) facets, the prepared BiVO4 material possessed a single monoclinic scheelite structure. A diffraction peak at 38.1° was observed in the Ag-related photocatalysts (Fig. 1a) corresponding to the (111) crystal phase of metallic Ag (JCPDS file: 65-2871). This indicates that the photoreduction of Ag+ ions indeed occurred, leading to the deposition of Ag nanoparticles on the BiVO4 and BiV1-xMoxO4 surfaces. Nevertheless, due to the low relative content of Ag, the XRD peaks were not intense. As shown in Fig. 2a, EDS confirmed the presence of the Ag species, which agrees with the XRD results. The Bi (Fig. 2b), O (Fig. 2c), V (Fig. 2d), Mo (Fig. 2e), and Ag (Fig. 2f ) elements are all distributed uniformly in the Ag/BiV1-xMoxO4 composites, and the results verify the existence of Mo and Ag. The relative amounts of Mo did not appear to affect the crystal structure or phase. The Mo substitution ratio was assessed by ICP (Table 1); the practical Mo atomic content was calculated to be 0.16% in Ag/BiV0.9925Mo0.0075O4. It was observed that, although the nominal dopant content introduced with the precursors was 0.75%, the final resulting amount of Mo in the doped materials was always lower than the expected. Similar results have also been found in previous research, and it is possible that intrinsic losses and the evaporation of the Mo dopant occur during the hydrothermal synthesis processes [ 35, 36 ]. The morphology of the as-prepared pure BiVO4, Ag/ BiVO4, and Ag/BiV1-xMoxO4 were investigated by SEM (Fig. 3). Pure BiVO4 showed a slice-layer morphology with several clusters (Fig. 3a, b). For Ag/BiVO4, metallic Ag was observed to be well dispersed on the (040) crystal facet (Fig. 3c), which agrees with the XRD analysis. The images of Ag/BiV0.9925Mo0.0075O4 composite at different magnification were shown in Fig. 3e, d. Uniformly shaped metallic Ag nanoparticles were clearly observed on the surface of Ag/BiV0.9925Mo0.0075O4 (Fig. 3d) likely due to the high exposure of the (040) surface. This crystal facet has been shown to have a good charge carrier mobility [ 37 ]. Thus, the observed morphology should be beneficial to the photocatalytic performance of the synthesized doped BiVO4 powders. The as-prepared BiVO4, Ag/BiVO4, and Ag/BiV0.9925Mo0.0075O4 samples were further observed by TEM (Fig. 4a). Interplanar spacings of 0.475 nm were clearly observed in Fig. 4b, corresponding to the (110) crystallographic facet of BiVO4 (JCPDS Card No. 14-0688). The crystal lattice fringe at 0.226 nm belonged to the (111) plane of metallic Ag nanoparticles in the Ag/BiVO4 and Ag/BiV0.9925Mo0.0075O4 samples (Fig. 4d, f ). Based on the above analyses, metallic Ag was successfully deposited onto the BiV0.9925Mo0.0075O4 surface, leading to a good connection between Ag and the Mo-doped BiVO4 and promoting effective electron and hole separation in the composite system. XPS analysis of the as-prepared samples confirmed the presence of Bi, V, O, Ag, and Mo (Fig. 5a). The binding energies of Bi 4f were 158.94 and 164.27 eV, corresponding to Bi 4f7/2 and 4f5/2, respectively, confirming the Bi3+ peaks in BiVO4 (Fig. 5b). A typical O 1s spectrum was observed, as indicated by the main characteristic peak at 529.71 eV (Fig. 5c). The V 2p3/2 and 2p1/ 2 peaks observed at 516.5 and 524.1 eV, respectively, indicated the existence of V5+ (Fig. 5d). The Ag 3d peaks at 367.98 and 374.0 eV, corresponding to Ag 3d5/2 and 3d3/2 (Fig. 5e), respectively, were observed in both Ag/ BiVO4 and Ag/BiV0.9925Mo0.0075O4, confirming the existence of the metallic Ag species. Furthermore, the molar ratio of metallic Ag species accounted for 6.6% of all elements, as determined by XPS and in agreement with the ICP measurements (Table 1). Finally, the Mo 3d5/2 and 3d3/2 peaks located at 231.7 and 234.9 eV (Fig. 5f ), respectively, confirm the presence of Mo6+. UV–vis diffuse reflectance spectrum measurements were taken to evaluate the optical bandgap and absorption properties of the photocatalysts, as shown in Fig. 5. The photocatalytic activity of a semiconductor is largely dependent on the size of the bandgap; the narrower the bandgap is, the greater the shift is of the absorption wavelength towards longer wavelengths. The bandgap of as-prepared BiVO4 was approximately 2.3 eV (Fig. 6b), which agrees with the Kubelka–Munk bandgap estimation theory [ 38 ]. Compared with BiVO4, all the Modoped samples showed relatively narrow bandgaps (Fig. 6b). Furthermore, all Ag-deposited BiVO4 and BiV1-xMoxO4 photocatalysts exhibited strong absorption in the visible light range in Fig. 6a. The Ag/BiVO4 photocatalyst exhibited the best light absorption. The absorbance of as-prepared Ag/BiV0.9925Mo0.0075O4 was between that of BiVO4 and Ag/BiVO4, thus indicating that the introduction of Mo hindered the photoresponsive characteristics of Ag. However, it is worth pointing out that, in addition to photoabsorption, other characteristics can also significantly influence the photocatalytic efficiency of photocatalysts. Photoluminescence (PL) spectras were taken to investigate the separation efficiency of the photogenerated electron–hole pairs. The PL spectra of pure BiVO4, BiV0.9925Mo0.0075O4, Ag/BiVO4, and Ag/BiV0.9925Mo0.0075O4 composites, with an excitation wavelength of 310 nm, are shown in Fig. 7. BiVO4 and BiV0.9925Mo0.0075O4 show a prominent emission band centered at approximately 510 nm. The order of the intensity of the PL spectra was BiVO4 > BiV0.9925Mo0.0075O4 > Ag/BiVO4 > Ag/BiV0.9925Mo0.0075O4. Because a lower PL intensity indicates a higher separation efficiency, this would lead to a higher photocatalytic activity in the overall system. Consequently, the higher photocatalytic performance of Ag/BiV0.9925Mo0.0075O4 agrees with the PL measurement. The photocatalytic decomposition results, according to the degradation of RhB under visible light (λ > 420 nm), confirmed Ag or Mo alone had little effect on the catalytic activity of BiVO4 under light irradiation for 2 h (Fig. 8). Conversely, the deposition of Ag on Modoped BiVO4 showed effective photocatalytic activity, with the variation of the Mo content, showing a difference in photocatalytic activity. Ag/BiV0.9925Mo0.0075O4 exhibited an extremely efficient degradation of RhB under visible light irradiation with full decolorization after 2 h while only 7, 8, and 10% degradation was achieved over BiVO4, Ag/BiVO4, and BiV0.9925Mo0.0075O4, respectively. Thus, Mo-doped Agdeposited BiVO4 was able to suppress the charge Fig. 9 Five cycle runs of Ag/BiV0.9925Mo0.0075O4 for the photodegradation of RhB under visible light irradiation recombination and greatly enhance the efficiency of the photocatalytic process. The stability and reusability of photocatalysts are very important for their practical application. Therefore, we assessed the repeated cycles of Ag/BiV0.9925Mo0.0075O4 in the photocatalytic degradation of RhB for 2 h under visible light irradiation. Overall, 99% of the RhB solution was degraded after five cycles (Fig. 9), indicating that the sample exhibited good photocatalytic stability. To further assess the separation efficiency, the charge carrier lifetimes of pure BiVO4, Ag/BiVO4, and Ag/ BiV0.9925Mo0.0075O4 were also analyzed (Fig. 10). The decay curves for the as-prepared photocatalysts fit well to a double-exponential function. The charge carrier decay lifetimes of BiVO4, Ag/BiVO4, and Ag/BiV0.9925Mo0.0075O4 composites were 1.2304, 1.8220, and 2.0933 ns, respectively. Thus, the Ag-deposited samples, both with and without Mo doping, had much longer charge carrier lifetimes than pure BiVO4, achieving effective photocarrier separation and suggesting that a synergistic effect among Ag, Mo, and BiVO4 led to enhancements of the photocatalytic activity. To explore the underlying photocatalytic mechanism, RhB degradation was conducted under visible light irradiation [ 39 ], adding a hole (h+) scavenger (ammonium oxalate ((NH4)2C2O4)), a superoxide radical ( O2−) scavenger (1.4-benzoquinone, BQ) [ 40 ], or hydroxyl radical ( OH) scavengers (tert-Butanol, t-BuOH) [ 41 ]. Following the addition of BQ, no obvious decrease was observed, but an acceleration in the degradation rate was detected compared to that of Ag/BiV0.9925Mo0.0075O4 (Fig. 11). The faster degradation rate may have resulted from the SPR-effect of metallic Ag in Ag/ BiV0.9925Mo0.0075O4, which would enhance the separation efficiency of electrons and holes. However, when t-BuOH was added, the catalytic efficiency decreased from 97.5 to 78.1%, indicating the presence of OH as the active species. The photocatalytic activity was drastically reduced with the addition of (NH4)2C2O4, suggesting that the holes acted as the main active species. To further confirm the main active species generated in the photocatalytic process, electron spin resonance (ESR) was used. The principle of ESR is to react with free radicals using a spin-trapping agent to generate a relatively stable free radical adduct. A peak intensity was observed under visible light compared with dark conditions (Fig. 12a), demonstrating the existence of O2−. In Fig. 11 Plots of photogenerated carrier trapping in the system during the photodegradation of RhB by Ag/BiV0.9925Mo0.0075O4 addition, obvious signals (Fig. 12b) suggested that OH was produced in the photocatalytic process. In conclusion, the radical trap experiments and ESR analysis revealed that the photocatalytic process was governed by the combined effect of h+, O2−, and OH active species. According to the discussion above, a possible photocatalytic mechanism of Ag/BiV0.9925Mo0.0075O4 was illustrated in Fig. 13. The dopant Mo could effectively enhance the visible light absorption of the BiVO4 photocatalyst. Ag/BiV0.9925Mo0.0075O4 composite photocatalysts were irradiated under visible light, and the photoelectrons in the valence band of BiVO4 could effectively jump to the conduction band to generate electron–hole pairs. The metallic Ag could accept the electrons, which then recombine with the photogenerated holes and enhance the transfer to the surface of the composite photocatalysts, resulting in the improvement of the separation of electrons and holes. The electrons could react to the O2 and transform to O2−. The holes of BiV0.9925Mo0.0075O4 could react with the adsorbed H2O molecules and transform to OH. Meanwhile, the h+ could effectively react with the RhB, generating degraded products. Conclusions Herein, a simple hydrothermal synthesis procedure at almost neutral pH conditions and using ammonium carbonate as the structure-directing agent is reported for the preparation of Mo-doped BiVO4 powders. Metallic Ag nanoparticles were then deposited on the (040) crystal facet of BiV0.9925Mo0.0075O4. Thus, a photocatalytic system has been successfully constructed by means of the reduction reaction. These synthesis conditions have been shown to significantly influence the increase in the size of the (040) crystallographic facet, as confirmed by XRD and STEM analyses. The XRD indicated that the peak splitting observed at 30.5° is a result of the (040) facets. Ag nanoparticles deposited on the (040) facets can also be seen from the STEM. Furthermore, Ag/ BiV0.9925Mo0.0075O4 showed a highly efficient photocatalytic performance for RhB degradation under visible light irradiation. This work could offer new inspiration for the rational utilization of BiVO4 photocatalysts with high photocatalytic activity and their applications in the fields of energy production and environmental protection. Acknowledgements The authors acknowledge the financial support from the NSFC (Grant No. 51602111), Guangdong Provincial Grant (2015A030310196, 2014B090915005), the Pearl River S&T Nova Program of Guangzhou (201506040045), Xijiang R&D team(X W), the Program for Changjiang Scholars and Innovative Research Teams in Universities (No. IRT13064), the Hundred Talent Program of Chinese Academy Sciences (QG Meng), Guangzhou Post-doctoral Initial Funding and the National 111 Project. Authors’ contributions XW and ZC conceived and designed the experiments. MY and SZ performed the experiments. XW, QM, MY, and GZ analyzed the data. XW contributed reagents/materials/analysis tools. All authors read and approved the final manuscript. Competing interests The authors declare that they have no competing interests. Publisher’s Note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. 1. Dincer I ( 2000 ) Renewable energy and sustainable development: a crucial review . Renew Sustainable Energy Rev 4 : 157 - 175 2. Huang C-K , Wu T , Huang C-W , Lai C-Y , Wu M-Y, Lin Y-W ( 2017 ) Enhanced photocatalytic performance of BiVO4 in aqueous AgNO3 solution under visible light irradiation . Appl Surf Sci 399 : 10 - 19 3. Ding X , Zhao K , Zhang L ( 2014 ) Enhanced photocatalytic removal of sodium pentachlorophenate with self-doped Bi2WO6 under visible light by generating more superoxide ions . Environ Sci Technol 48 : 5823 - 5831 4. Yang JJ , Chen DM , Zhu Y , Zhang YM , Zhu YF ( 2017 ) 3D-3D porous Bi2WO6 /graphene hydrogel composite with excellent synergistic effect of adsorptionenrichment and photocatalytic degradation . Appl Catal B Environ 205 : 228 - 237 5. Zhu YY , Wang YJ , Ling Q , Zhu YF ( 2017 ) Enhancement of full-spectrum photocatalytic activity over BiPO4/Bi2WO6 clomposites . Appl Catal B Environ 200 : 222 - 229 6. Tan GQ , She LN , Liu T , Xu C , Ren HJ , Xia A ( 2017 ) Ultrasonic chemical synthesis of hybrid mpg-C3N4/BiPO4 heterostructured photocatalysts with improved visible light photocatalytic activity . Appl Catal B Environ 207 : 120 - 133 7. Bi Y , Ouyang S , Umezawa N , Cao J , Ye J ( 2011 ) Facet effect of single-crystalline Ag3PO4 sub-microcrystals on photocatalytic properties . J Am Chem Soc 133 : 6490 - 6492 8. Teng W , Tan XJ , Li XY , Tang YB ( 2017 ) Novel Ag3PO4/MoO3 p-n heterojunction with enhanced photocatalytic activity and stability under visible light irradiation . Appl Surf Sci 409 : 250 - 260 9. Xue-lian Y , Yuan C , Bi-tao L , Ming-jing T ( 2016 ) Progress in BiVO4 photocatalyst under visible light . Mater Sci Forum 852 : 1429 - 1435 10. Obregon S , Colon G ( 2013 ) On the different photocatalytic performance of BiVO4 catalysts for methylene blue and rhodamine B degradation . J Mol Catal A Chem 376 : 40 - 47 11. Ng YH , Iwase A , Kudo A , Amal R ( 2010 ) Reducing graphene oxide on a visible-light BiVO4 photocatalyst for an enhanced photoelectrochemical water splitting . J Phys Chem Lett 1 : 2607 - 2612 12. Kim JH , Lee JS ( 2014 ) BiVO4-based heterostructured photocatalysts for solar water splitting: a review . Energy Environ Focus 3 : 339 - 353 13. Liang Y , Messinger J ( 2014 ) Improving BiVO4 photoanodes for solar water splitting through surface passivation . Phys Chem Chem Phys 16 : 12014 - 12020 14. Fujishima A , Honda K ( 1972 ) Electrochemical photolysis of water at a semiconductor electrode . Nature 238 : 37 - 38 15. Zhang N , Li X , Ye H , Chen S , Ju H , Liu D , Lin Y , Ye W , Wang C , Xu Q , Zhu J , Song L , Jiang J , Xiong Y ( 2016 ) Oxide defect engineering enables to couple solar energy into oxygen activation . J Am Chem Soc 138 : 8928 - 8935 16. Reece SY , Hamel JA , Sung K , Jarvi TD , Esswein AJ , Pijpers JJ , Nocera DG ( 2011 ) Wireless solar water splitting using silicon-based semiconductors and earth-abundant catalysts . Science 334 : 645 - 648 17. Zhao J , Yan J , Jia H , Zhong S , Zhang X , Xu L ( 2016 ) BiVO4/g-C3N4 composite visible-light photocatalyst for effective elimination of aqueous organic pollutants . J Mol Catal A Chem 424 : 162 - 170 18. Ma G , Chen Z , Chen Z , Jin M , Meng Q , Yuan M , Wang X , Liu J-M , Zhou G ( 2017 ) Constructing novel WO3/Fe (III) nanofibers photocatalysts with enhanced visible-light-driven photocatalytic activity via interfacial charge transfer effect . Mater Today Energy 3 : 45 - 52 19. Chen F , Yang Q , Wang Y , Zhao J , Wang D , Li X , Guo Z , Wang H , Deng Y , Niu C , Zeng G ( 2017 ) Novel ternary heterojunction photcocatalyst of Ag nanoparticles and g-C3N4 nanosheets co-modified BiVO4 for wider spectrum visible-light photocatalytic degradation of refractory pollutant . Appl Catal B Environ 205 : 133 - 147 20. Xue S , He H , Wu Z , Yu C , Fan Q , Peng G , Yang K ( 2017 ) An interesting Eu,F-codoped BiVO4 microsphere with enhanced photocatalytic performance . J Alloys Compd 694 : 989 - 997 21. Zhang J , Ren F , Deng M , Wang Y ( 2015 ) Enhanced visible-light photocatalytic activity of a g-C3N4/BiVO4 nanocomposite: a first-principles study . Phys Chem Chem Phys 17 : 10218 - 10226 22. Zhou Y , Li W , Wan W , Zhang R , Lin Y ( 2015 ) W/Mo co-doped BiVO4 for photocatalytic treatment of polymer-containing wastewater in oilfield . Superlattice Microst 82 : 67 - 74 23. Wang K , Liang L , Liu H , Xie X , Hao Q , Liu C ( 2015 ) Facile synthesis of hollow and porous Ag+/Ag/BiVO4 composite fibers with enhanced visible-light photocatalytic performance . Mater Lett 161 : 336 - 339 24. Wang J , Shi W , Liu D , Zhang Z , Zhu Y , Wang D ( 2017 ) Supramolecular organic nanofibers with highly efficient and stable visible light photooxidation performance . Appl Catal B Environ 202 : 289 - 297 25. Pattengale B , Huang J ( 2016 ) The effect of Mo doping on the charge separation dynamics and photocurrent performance of BiVO4 photoanodes . Phys Chem Chem Phys 18 : 32820 - 32825 26. Antony RP , Baikie T , Chiam SY , Ren Y , Prabhakar RR , Batabyal SK , Loo SCJ , Barber J , Wong LH ( 2016 ) Catalytic effect of Bi5+ in enhanced solar water splitting of tetragonal BiV0 . 8Mo0.2O4. Appl Catal A 526 : 21 - 27 27. Seabold JA , Zhu K , Neale NR ( 2014 ) Efficient solar photoelectrolysis by nanoporous Mo: BiVO4 through controlled electron transport . Phys Chem Chem Phys 16 : 1121 - 1131 28. Parmar KPS , Kang HJ , Bist A , Dua P , Jang JS , Lee JS ( 2012 ) Photocatalytic and photoelectrochemical water oxidation over metal-doped monoclinic BiVO4 photoanodes . ChemSusChem 5 : 1926 - 1934 29. Thalluri SM , Hernandez S , Bensaid S , Saracco G , Russo N ( 2016 ) Green-synthesized W- and Mo-doped BiVO4 oriented along the {040} facet with enhanced activity for the sun-driven water oxidation . Appl Catal B Environ 180 : 630 - 636 30. Luo W , Wang J , Zhao X , Zhao Z , Li Z , Zou Z ( 2013 ) Formation energy and photoelectrochemical properties of BiVO4 after doping at Bi3+ or V5+ sites with higher valence metal ions . Phys Chem Chem Phys 15 : 1006 - 1013 31. Qiao R , Mao M , Hu E , Zhong Y , Ning J , Hu Y ( 2015 ) Facile formation of mesoporous BiVO4/Ag/AgCl heterostructured microspheres with enhanced visible-light photoactivity . Inorg Chem 54 : 9033 - 9039 32. Gao XM , Wu YF , Wang J , Fu F , Zhang LP , Niu FX ( 2012 ) The preparation of Cu-BiVO4 and its enhanced photocatalytic properties for degradation of Phenol . Adv Mater Res 356 : 1253 - 1257 33. Hirakawa H , Shiota S , Shiraishi Y , Sakamoto H , Ichikawa S , Hirai T ( 2016 ) Au nanoparticles supported on BiVO4: Effective inorganic photocatalysts for H2O2 production from water and O2 under visible light . ACS Catal 6 : 4976 - 4982 34. Li J , Zhou J , Hao H , Zhu Z ( 2016 ) Silver-modified specific (040) facet of BiVO4 with enhanced photoelectrochemical performance . Mater Lett 170 : 163 - 166 35. Yao W , Iwai H , Ye J ( 2008 ) Effects of molybdenum substitution on the photocatalytic behavior of BiVO4 . Dalton Trans 11 : 1426 - 1430 36. Pilli SK , Furtak TE , Brown LD , Deutsch TG , Turner JA , Herring AM ( 2011 ) cobalt-phosphate (Co-Pi) catalyst modified Mo-doped BiVO4 photoelectrodes for solar water oxidation . Energy Environ Sci 4 : 5028 - 5034 37. Li R , Zhang F , Wang D , Yang J , Li M , Zhu J , Zhou X , Han H , Li C ( 2013 ) Spatial separation of photogenerated electrons and holes among {010} and {110} crystal facets of BiVO4 . Nat Commun 4 : 1432 - 1438 38. Ni Z , Dong F , Huang H , Zhang Y ( 2016 ) New insights into how Pd nanoparticles influence the photocatalytic oxidation and reduction ability of g-C3N4 nanosheets . Catal Sci Technol 6 : 6448 - 6458 39. Chen F , Yang Q , Li X , Zeng G , Wang D , Niu C , Zhao J , An H , Xie T , Deng Y ( 2017 ) Hierarchical assembly of graphene-bridged Ag3PO4/Ag/BiVO4 (040) Z-scheme photocatalyst: An efficient, sustainable and heterogeneous catalyst with enhanced visible-light photoactivity towards tetracycline degradation under visible light irradiation . Appl Catal B Environ 200 : 330 - 342 40. Chen F , Yang Q , Niu C , Li X , Zhang C , Zhao J , Xu Q , Zhong Y , Deng Y , Zeng G ( 2016 ) Enhanced visible light photocatalytic activity and mechanism of ZnSn(OH)6 nanocubes modified with AgI nanoparticles . Catal Commun 73 : 1 - 6 41. Dong G , Ho W , Zhang L ( 2015 ) Photocatalytic NO removal on BiOI surface: the change from nonselective oxidation to selective oxidation . Appl Catal B Environ 168 : 490 - 496

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Mengting Yu, Shixiong Zhou, Qingguo Meng, Haiqin Lv, Zhihong Chen, Yongguang Zhang, Mingliang Jin, Mingzhe Yuan, Xin Wang, Guofu Zhou. Synergistic Effects of Ag Nanoparticles/BiV1-xMoxO4 with Enhanced Photocatalytic Activity, Nanoscale Research Letters, 2017, 588, DOI: 10.1186/s11671-017-2345-9