Bismuth tungstate(Bi_(2)WO_(6))has become a research hotspot due to its potential in photocatalytic energy conversion and environmental purification.Nevertheless,the limited light absorption and fast recombination of ...Bismuth tungstate(Bi_(2)WO_(6))has become a research hotspot due to its potential in photocatalytic energy conversion and environmental purification.Nevertheless,the limited light absorption and fast recombination of photogenerated carriers hinder the further improvement of the photocatalytic performance of Bi_(2)WO_(6).Herein,we provide a systematic review for the recent advances on Bi_(2)WO_(6)‐based photocatalysts.It starts with the crystal structure,optical properties and photocatalytic fundamentals of Bi_(2)WO_(6).Then,we focus on the modification strategies of Bi_(2)WO_(6)based on morphology control,atomic modulation and composite fabrication for diverse photocatalytic applications,such as organic synthesis,water splitting,CO2 reduction,water treatment,air purification,bacterial inactivation,etc.Finally,some current challenges and future development prospects are proposed.We expect that this review can provide a useful reference and guidance for the development of efficient Bi_(2)WO_(6)photocatalysts.展开更多
Although the traditional Fenton reaction is considered an effective strategy for solving problems caused by environmental pollution,construction of an efficient photocatalytic system by coordinating the Fenton reactio...Although the traditional Fenton reaction is considered an effective strategy for solving problems caused by environmental pollution,construction of an efficient photocatalytic system by coordinating the Fenton reaction is challenging.In this study,2D/2D step-schemeα-Fe2O3/Bi2WO6(FO/BWO)heterostructure photo-Fenton catalysts were successfully fabricated by a facile hydrothermal method.The as-prepared materials were characterized by XRD,FT-IR,TEM,XPS,UV-vis DRS,PL,I-t,EIS,and BET analyses.Under visible light irradiation,FO/BWO exhibited remarkably high and stable photo-Fenton catalytic activity for the degradation of methyl blue(MB)at low concentrations of H2O2.It was noted that FO/BWO(0.5)displayed a significantly enhanced photo-Fenton catalytic activity,which was 11.06 and 3.29 times those of FO nanosheets and BWO nanosheets,respectively.The notably improved photo-Fenton catalytic activity of FO/BWO was mainly due to the combination of H2O2 and FO under light illumination and the presence of the 2D/2D S-scheme heterostructure,with the large contact surface,abundant active sites,and efficient separation rate of photogenerated carriers playing contributory roles.Additionally,a possible catalytic mechanism for the FO/BWO composite was preliminarily proposed via active species trapping experiments.In summary,this study provided new insights into the synthesis of an effectively heterogeneous 2D/2D S-scheme photo-Fenton catalyst for degradation of organic pollutants in wastewater.展开更多
The development of Bi2WO6-based materials has become one of research hotspots due to the increasing demands on high-efficient photocatalyst responding to visible light.In this work,the effect of high energy radiation(...The development of Bi2WO6-based materials has become one of research hotspots due to the increasing demands on high-efficient photocatalyst responding to visible light.In this work,the effect of high energy radiation(γ-ray)on the structure and the photocatalytic activity of Bi2WO6 nanocrystals was first studied.No morphological change of Bi2WO6 nanocrystals was observed by SEM underγ-ray radiation.However,the XRD spectra of the irradiated Bi2WO6 nanocrystals showed the characteristic 2θof(113)plane shifts slightly from 28.37o to 28.45o with the increase of the absorbed dose,confirming the change in the crystal structure of Bi2WO6.The XPS results proved the crystal structure change was originated from the generation of oxygen vacancy defects under high-dose radiation.The photocatalytic activity of Bi2WO6 on the decomposition of methylene blue(MB)in water under visible light increases gradually with the increase of absorbed dose.Moreover,the improved photocatalytic performance of the irradiated Bi2WO6 nanocrystals remained after three cycles of photocatalysis,indicating a good stability of the created oxygen vacancy defects.This work gives a new simple way to improve photocatalytic performance of Bi2WO6 through creating oxygen vacancy defects in the crystal structure by-ray radiation.展开更多
Bi_2WO_6 was modified by two-dimensional g-C_3N_4(2D g-C_3N_4)via a hydrothermal method.The structure,morphology,optical and electronic properties were investigated by multiple techniques,including X-ray diffraction(X...Bi_2WO_6 was modified by two-dimensional g-C_3N_4(2D g-C_3N_4)via a hydrothermal method.The structure,morphology,optical and electronic properties were investigated by multiple techniques,including X-ray diffraction(XRD),X-ray photoelectron spectroscopy spectra(XPS),Fourier transform infrared spectroscopy(FT-IR),scanning electron microscopy(SEM),transmission electron microscopy(TEM),Ultravioletvisible diffuse reflection spectroscopy(DRS),photocurrent and electrochemical impedance spectroscopy(EIS),electron spin resonance(ESR),respectively.Rhodamine B(Rh B)was used as the target organic pollutant to research the photocatalytic performance of as-prepared composites.The Bi_2WO_6/2D g-C_3N_4exhibited a remarkable improvement compared with the pure Bi_2WO_6.The enhanced photocatalytic activity was because the photogenerated electrons and holes can quickly separate by Z-Scheme passageway in composites.The photocatalytic mechanism was also researched in detail through ESR analysis.展开更多
Bismuth tungstate(Bi2 WO6) has many intriguing properties and has been the focus of studies in a variety of fields, especially photocatalysis. However, its application in gas-sensing has been seldom reported.Here, we ...Bismuth tungstate(Bi2 WO6) has many intriguing properties and has been the focus of studies in a variety of fields, especially photocatalysis. However, its application in gas-sensing has been seldom reported.Here, we successfully synthesized assembled hierarchical Bi2 WO6 which consists of ultrathin nanosheets with crystalline-amorphous composite phase by a one-step hydrothermal method. X-ray diffraction(XRD), X-ray photoemission spectroscopy(XPS), field-emission scanning electron microscopy(FESEM),and high-resolution transmission electron microscopy(HRTEM) techniques were employed to characterize its composition, morphology, and microstructure. By taking advantage of its unique microstructure,phase composition, and large surface area, we show that the resulting Bi2 WO6 is capable of detecting ethanol gas with quick response(7 s) and recovery dynamic(14 s), extremely high sensitivity(Ra/Rg= 60.8@50 ppm ethanol) and selectivity. Additionally, it has excellent reproducibility and long-term stability(more than 50 d). The Bi2 WO6 outperform the existing Bi2 WO6-based and most of the other state-of-the-art sensing platforms. We not only provided one new member to the field of gas sensor,but also offered several strategies to reconstruct nanomaterials.展开更多
Hierarchical Ag/Bi2WO6 nanomaterials were prepared by a facile one-step hydrothermal method in mixed acetic acid and ethylene glycol (EG) medium. EG is employed as mild reducing agent for the formation of metallic Ag ...Hierarchical Ag/Bi2WO6 nanomaterials were prepared by a facile one-step hydrothermal method in mixed acetic acid and ethylene glycol (EG) medium. EG is employed as mild reducing agent for the formation of metallic Ag from Ag+ precursors. In situ energy dispersive X-ray diffraction (EDXRD) monitoring showed that the hydrothermal formation kinetics of Bi2WO6 in the presence of EG was significantly slowed down due to its very high viscosity. The photocatalytic activities of Ag/Bi2WO6 composites were evaluated by the photodegradation of methylene blue (MB) under visible light irradiation. The photocatalytic activity of Bi2WO6 is strongly influenced by the Ag loading. The enhanced catalytic activity of the composites is based on the cooperative effects of plasmon absorption band and separation of photogenerated electron-hole pairs.展开更多
Bi2WO6 was modified with MnOx via a photodeposition method. Multiple techniques including XRD, SEM, TEM, UV-Vis and XPS were applied to investigate the structures, morphologies and optical characteristics of the as-pr...Bi2WO6 was modified with MnOx via a photodeposition method. Multiple techniques including XRD, SEM, TEM, UV-Vis and XPS were applied to investigate the structures, morphologies and optical characteristics of the as-prepared sample. The nanostructured composites were formed with MnOx loaded on the surface of flower-like Bi2WO6, where MnOx exists as a mixed-valence manganese of Mn3＋ and Mn4＋ as verified by XPS. The photocatalytic activity of the MnOx/Bi2WO6 composites was evaluated by using rhodamine B （RhB） as a target organic pollutant under visible light irradiation. The as-prepared MnOx/Bi2WO6 composites exhibited much higher photo- catalytic activities than pure Bi2WO6. The enhanced activities were attributed to the interfacial transfer of photo- generated holes from Bi2WO6 to MnOx, leading to effective way to improve photocatalytic efficiency, which may be extended to a strategy for other semiconductor. Based on the experimental results, a possible mechanism of MnOx for the enhancement of visible light performance was proposed.展开更多
文摘Bismuth tungstate(Bi_(2)WO_(6))has become a research hotspot due to its potential in photocatalytic energy conversion and environmental purification.Nevertheless,the limited light absorption and fast recombination of photogenerated carriers hinder the further improvement of the photocatalytic performance of Bi_(2)WO_(6).Herein,we provide a systematic review for the recent advances on Bi_(2)WO_(6)‐based photocatalysts.It starts with the crystal structure,optical properties and photocatalytic fundamentals of Bi_(2)WO_(6).Then,we focus on the modification strategies of Bi_(2)WO_(6)based on morphology control,atomic modulation and composite fabrication for diverse photocatalytic applications,such as organic synthesis,water splitting,CO2 reduction,water treatment,air purification,bacterial inactivation,etc.Finally,some current challenges and future development prospects are proposed.We expect that this review can provide a useful reference and guidance for the development of efficient Bi_(2)WO_(6)photocatalysts.
文摘Although the traditional Fenton reaction is considered an effective strategy for solving problems caused by environmental pollution,construction of an efficient photocatalytic system by coordinating the Fenton reaction is challenging.In this study,2D/2D step-schemeα-Fe2O3/Bi2WO6(FO/BWO)heterostructure photo-Fenton catalysts were successfully fabricated by a facile hydrothermal method.The as-prepared materials were characterized by XRD,FT-IR,TEM,XPS,UV-vis DRS,PL,I-t,EIS,and BET analyses.Under visible light irradiation,FO/BWO exhibited remarkably high and stable photo-Fenton catalytic activity for the degradation of methyl blue(MB)at low concentrations of H2O2.It was noted that FO/BWO(0.5)displayed a significantly enhanced photo-Fenton catalytic activity,which was 11.06 and 3.29 times those of FO nanosheets and BWO nanosheets,respectively.The notably improved photo-Fenton catalytic activity of FO/BWO was mainly due to the combination of H2O2 and FO under light illumination and the presence of the 2D/2D S-scheme heterostructure,with the large contact surface,abundant active sites,and efficient separation rate of photogenerated carriers playing contributory roles.Additionally,a possible catalytic mechanism for the FO/BWO composite was preliminarily proposed via active species trapping experiments.In summary,this study provided new insights into the synthesis of an effectively heterogeneous 2D/2D S-scheme photo-Fenton catalyst for degradation of organic pollutants in wastewater.
基金supported by the National Natural Science Foundation of China (No.51473152, No.51573174, and No.51773189)Science Challenge Project (No.TZ2018004)the Fundamental Research Funds for the Central Universities (WK3450000001 and WK3450000004)
文摘The development of Bi2WO6-based materials has become one of research hotspots due to the increasing demands on high-efficient photocatalyst responding to visible light.In this work,the effect of high energy radiation(γ-ray)on the structure and the photocatalytic activity of Bi2WO6 nanocrystals was first studied.No morphological change of Bi2WO6 nanocrystals was observed by SEM underγ-ray radiation.However,the XRD spectra of the irradiated Bi2WO6 nanocrystals showed the characteristic 2θof(113)plane shifts slightly from 28.37o to 28.45o with the increase of the absorbed dose,confirming the change in the crystal structure of Bi2WO6.The XPS results proved the crystal structure change was originated from the generation of oxygen vacancy defects under high-dose radiation.The photocatalytic activity of Bi2WO6 on the decomposition of methylene blue(MB)in water under visible light increases gradually with the increase of absorbed dose.Moreover,the improved photocatalytic performance of the irradiated Bi2WO6 nanocrystals remained after three cycles of photocatalysis,indicating a good stability of the created oxygen vacancy defects.This work gives a new simple way to improve photocatalytic performance of Bi2WO6 through creating oxygen vacancy defects in the crystal structure by-ray radiation.
基金supported by National Nature Science Foundation of China (21476097, 21776118)Six talent peaks project in Jiangsu Province (2014-JNHB-014)Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘Bi_2WO_6 was modified by two-dimensional g-C_3N_4(2D g-C_3N_4)via a hydrothermal method.The structure,morphology,optical and electronic properties were investigated by multiple techniques,including X-ray diffraction(XRD),X-ray photoelectron spectroscopy spectra(XPS),Fourier transform infrared spectroscopy(FT-IR),scanning electron microscopy(SEM),transmission electron microscopy(TEM),Ultravioletvisible diffuse reflection spectroscopy(DRS),photocurrent and electrochemical impedance spectroscopy(EIS),electron spin resonance(ESR),respectively.Rhodamine B(Rh B)was used as the target organic pollutant to research the photocatalytic performance of as-prepared composites.The Bi_2WO_6/2D g-C_3N_4exhibited a remarkable improvement compared with the pure Bi_2WO_6.The enhanced photocatalytic activity was because the photogenerated electrons and holes can quickly separate by Z-Scheme passageway in composites.The photocatalytic mechanism was also researched in detail through ESR analysis.
基金supported by the National Key R&D Program of China (2017YFA0208300 and 2017YFA0700104)the National Natural Science Foundation of China (61671284, U1704255, and 21671180)the support of the Shanghai Municipal Education Commission (Peak Discipline Construction Program)
文摘Bismuth tungstate(Bi2 WO6) has many intriguing properties and has been the focus of studies in a variety of fields, especially photocatalysis. However, its application in gas-sensing has been seldom reported.Here, we successfully synthesized assembled hierarchical Bi2 WO6 which consists of ultrathin nanosheets with crystalline-amorphous composite phase by a one-step hydrothermal method. X-ray diffraction(XRD), X-ray photoemission spectroscopy(XPS), field-emission scanning electron microscopy(FESEM),and high-resolution transmission electron microscopy(HRTEM) techniques were employed to characterize its composition, morphology, and microstructure. By taking advantage of its unique microstructure,phase composition, and large surface area, we show that the resulting Bi2 WO6 is capable of detecting ethanol gas with quick response(7 s) and recovery dynamic(14 s), extremely high sensitivity(Ra/Rg= 60.8@50 ppm ethanol) and selectivity. Additionally, it has excellent reproducibility and long-term stability(more than 50 d). The Bi2 WO6 outperform the existing Bi2 WO6-based and most of the other state-of-the-art sensing platforms. We not only provided one new member to the field of gas sensor,but also offered several strategies to reconstruct nanomaterials.
基金supported by the National Natural Science Foundation of China (51102245 and U1232119)the Innovative Research Team of Southwest Petroleum University (2012XJZT002)the Swiss National Science Foundation (SNSF Professorship PP0P2-133483/1)
文摘Hierarchical Ag/Bi2WO6 nanomaterials were prepared by a facile one-step hydrothermal method in mixed acetic acid and ethylene glycol (EG) medium. EG is employed as mild reducing agent for the formation of metallic Ag from Ag+ precursors. In situ energy dispersive X-ray diffraction (EDXRD) monitoring showed that the hydrothermal formation kinetics of Bi2WO6 in the presence of EG was significantly slowed down due to its very high viscosity. The photocatalytic activities of Ag/Bi2WO6 composites were evaluated by the photodegradation of methylene blue (MB) under visible light irradiation. The photocatalytic activity of Bi2WO6 is strongly influenced by the Ag loading. The enhanced catalytic activity of the composites is based on the cooperative effects of plasmon absorption band and separation of photogenerated electron-hole pairs.
文摘Bi2WO6 was modified with MnOx via a photodeposition method. Multiple techniques including XRD, SEM, TEM, UV-Vis and XPS were applied to investigate the structures, morphologies and optical characteristics of the as-prepared sample. The nanostructured composites were formed with MnOx loaded on the surface of flower-like Bi2WO6, where MnOx exists as a mixed-valence manganese of Mn3＋ and Mn4＋ as verified by XPS. The photocatalytic activity of the MnOx/Bi2WO6 composites was evaluated by using rhodamine B （RhB） as a target organic pollutant under visible light irradiation. The as-prepared MnOx/Bi2WO6 composites exhibited much higher photo- catalytic activities than pure Bi2WO6. The enhanced activities were attributed to the interfacial transfer of photo- generated holes from Bi2WO6 to MnOx, leading to effective way to improve photocatalytic efficiency, which may be extended to a strategy for other semiconductor. Based on the experimental results, a possible mechanism of MnOx for the enhancement of visible light performance was proposed.
