Enhanced driving force and charge separation efficiency in disordered SnNb x O y : Boosting photocatalytic activity toward water reduction

Huang, Shushu; Lang, Junyu; Du, Chunfang; Bian, Fenggang; Su, Yiguo; Wang, Xiaojing

doi:10.1016/j.cej.2016.10.061

Cited by 24 publications

(24 citation statements)

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“…3), and the valence band of SnNb 2 O 6 was 1.435 eV. This result was closed to previous reported results of the conduction band (− 0.68 eV) and valence band (1.42 eV) edge potentials of SnNb 2 O 6 [43]. …”

Section: Resultscontrasting

confidence: 49%

“…3a) [42]. The band gap energy E g of the semiconductors (SnNb 2 O 6 and Sn 2 Nb 2 O 7 ) with an indirect electronic transition can be determined by the following equation: αhν = A (hν− E g ) 1/2 , where α, ν, E g , and A are the absorption coefficient, incident light frequency, band gap, and constant, respectively [25, 43]. As illustrated in Fig.…”

Section: Resultsmentioning

confidence: 99%

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Steering Charge Kinetics of Tin Niobate Photocatalysts: Key Roles of Phase Structure and Electronic Structure

et al. 2018

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Tin niobate photocatalysts with the phase structures of froodite (SnNb2O6) and pyrochlore (Sn2Nb2O7) were obtained by a facile solvothermal method in order to explore the impact of phase structure and electronic structure on the charge kinetics and photocatalytic performance. By employing tin niobate as a model compound, the effects of phase structure over electronic structure, photocatalytic activity toward methyl orange solution and hydrogen evolution were systematically investigated. It is found that the variation of phase structure from SnNb2O6 to Sn2Nb2O7 accompanied with modulation of particle size and band edge potentials that has great consequences on photocatalytic performance. In combination with the electrochemical impedance spectroscopy (EIS), transient photocurrent responses, transient absorption spectroscopy (TAS), and the analysis of the charge-carrier dynamics suggested that variation of electronic structure has great impacts on the charge separation and transfer rate of tin niobate photocatalysts and the subsequent photocatalytic performance. Moreover, the results of the X-ray photoelectron spectroscopy (XPS) indicated that the existent of Sn4+ species in Sn2Nb2O7 could result in a decrease in photocatalytic activity. Photocatalytic test demonstrated that the SnNb2O6 (froodite) catalyst possesses a higher photocatalytic activity toward MO degradation and H2 evolution compared with the sample of Sn2Nb2O7 (pyrochlore). On the basis of spin resonance measurement and trapping experiment, it is expected that photogenerated holes, O2−•, and OH• active species dominate the photodegradation of methyl orange.Electronic supplementary materialThe online version of this article (10.1186/s11671-018-2578-2) contains supplementary material, which is available to authorized users.

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Section: Resultscontrasting

confidence: 49%

Section: Resultsmentioning

confidence: 99%

Steering Charge Kinetics of Tin Niobate Photocatalysts: Key Roles of Phase Structure and Electronic Structure

et al. 2018

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“…Columbites are also founded in the literature with further applications in photocatalytic research. The effect of structural distortion of SnNb x O y in comparison with the crystalline SnNb 2 O 6 regarding the photocatalytic activity was investigated by Huang et al [48]. The crystalline sample exhibits a band gap energy of 2.10 eV, while the band gap energies for disordered and amorphous samples were 2.33 eV and 2.43 eV, respectively.…”

Section: Niobium Layered Compoundsmentioning

confidence: 99%

Recent Advances in Niobium-Based Materials for Photocatalytic Solar Fuel Production

et al. 2020

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The search for renewable and clean energy sources is a key aspect for sustainable development as energy consumption has continuously increased over the years concomitantly with environmental concerns caused by the use of fossil fuels. Semiconductor materials have great potential for acting as photocatalysts for solar fuel production, a potential energy source able to solve both energy and environmental concerns. Among the studied semiconductor materials, those based on niobium pentacation are still shallowly explored, although the number of publications and patents on Nb(V)-based photocatalysts has increased in the last years. A large variety of Nb(V)-based materials exhibit suitable electronic/morphological properties for light-driving reactions. Not only the extensive group of Nb2O5 polymorphs is explored, but also many types of layered niobates, mixed oxides, and Nb(V)-doped semiconductors. Therefore, the aim of this manuscript is to provide a review of the latest developments of niobium based photocatalysts for energy conversion into fuels, more specifically, CO2 reduction to hydrocarbons or H2 evolution from water. Additionally, the main strategies for improving the photocatalytic performance of niobium-based materials are discussed.

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“…The UV‐vis spectra (Figure d) showed that BS7 and Bi 2 O 3 both had a strong absorption in visible region, whereas SnO 2 exhibited unobservable visible light absorption (Figure d). On account of Bi 2 Sn 2 O 7 to show an indirect electronic transition (Figure S4), the E g (band gap energy) can be estimated by the following equation: αhν = A ( hν ‐ E g ) 1/2 , in which α , ν , E g , and A are the absorption coefficient, incident light frequency, band gap, and constant, respectively . As illustrated in the inset of Figure d, the band gap energies as well as the visible light absorption feature (Figure S5) of all as‐prepared samples were nearly identical with the variation of Sn(II) content, which can be identified by the comparison of DFT calculated band structure of Bi 2 Sn 2 O 7 and Sn(II)‐Bi 2 Sn 2 O 7 (Figures S6 and S7), proving that the content of Sn(II) in Bi 2 Sn 2 O 7 had minor impact on the visible light absorption capability.…”

Section: Resultsmentioning

confidence: 71%

Oxygen‐Vacancy‐Mediated Photocatalysis over Bi₂Sn₂O₇: Exceptional Catalytic Activity and Selectivity

Huang

Kou

et al. 2019

ChemCatChem

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A series of Bi2Sn2O7 photocatalysts was developed with the aim to regulate defect chemistry as well as electronic structure by modulating the charge states of tin species for boosting photocatalytic selective oxidation of alcohols performance. Defective centers, such as oxygen vacancies (OVs), were beneficial to enhancing the adsorption and activation of molecular oxygen. Meanwhile, the valence band edge potential of Bi2Sn2O7 with higher OVs content exhibited a distinct downshift, improving the thermodynamical driving force of photooxidation. Additionally, OVs contributed to promoting the separation efficiency of photogenerated carriers, which can be confirmed by the surface photovoltage measurement. By optimizing the electronic structure as well as defect chemistry, the optimal benzyl alcohol conversion efficiency was 76.0 % with selectivity toward benzaldehyde being about 100 %. It's found that photogenerated holes and .O2− active species played critical role in photocatalytic aerobic oxidation. This work may provide a novel insight to clarify the role of defect chemistry during the selective benzyl alcohol oxidation over Bi2Sn2O7 photocatalyst.

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Enhanced driving force and charge separation efficiency in disordered SnNb x O y : Boosting photocatalytic activity toward water reduction

Cited by 24 publications

References 60 publications

Steering Charge Kinetics of Tin Niobate Photocatalysts: Key Roles of Phase Structure and Electronic Structure

Steering Charge Kinetics of Tin Niobate Photocatalysts: Key Roles of Phase Structure and Electronic Structure

Recent Advances in Niobium-Based Materials for Photocatalytic Solar Fuel Production

Oxygen‐Vacancy‐Mediated Photocatalysis over Bi₂Sn₂O₇: Exceptional Catalytic Activity and Selectivity

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Enhanced driving force and charge separation efficiency in disordered SnNb x O y : Boosting photocatalytic activity toward water reduction

Cited by 24 publications

References 60 publications

Steering Charge Kinetics of Tin Niobate Photocatalysts: Key Roles of Phase Structure and Electronic Structure

Steering Charge Kinetics of Tin Niobate Photocatalysts: Key Roles of Phase Structure and Electronic Structure

Recent Advances in Niobium-Based Materials for Photocatalytic Solar Fuel Production

Oxygen‐Vacancy‐Mediated Photocatalysis over Bi2Sn2O7: Exceptional Catalytic Activity and Selectivity

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Oxygen‐Vacancy‐Mediated Photocatalysis over Bi₂Sn₂O₇: Exceptional Catalytic Activity and Selectivity