Title : ZnWO4-ZnIn2S4 S-scheme heterojunction for enhanced photocatalytic H2 evolution

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Title of Paper:ZnWO4-ZnIn2S4 S-scheme heterojunction for enhanced photocatalytic H2 evolution

Journal:Journal of Materials Science & Technology

Place of Publication:Elsevier

Key Words:Photocatalysts; H2 evolution; S-scheme heterojunction; Internal electric field; ZnWO4-ZnIn2S4 nanosheets

Abstract:The recombination of photogenerated electrons and holes is a crucial factor limiting photocatalytic H2 evolution. The S-scheme ZnWO4-ZnIn2S4 heterojunction with 2D coupling interfaces was successfully synthesized using a simple solvothermal method. An effective S-scheme interfacial charge migration route at the S-scheme heterogeneous interface was determined by energy band structure analyses (such as UPS, Mott-Schottky and XPS plots), which facilitates the separation of photoexcited carriers. It is worth noting that the optimal ZnWO4-ZnIn2S4 composite has an H2 evolution activity of 4925.3 μmol g−1 h−1 with favourable photostability and stability. Meanwhile, the ZnWO4-ZnIn2S4 heterojunction exhibits the maximum optical response value (2.8 mA cm−2) in the initial stage, effectively promoting the separation and migration of photogenerated carriers. The establishment of the built-in electric field direction at the interface can effectively promote the space charge separation between the ZnWO4 and ZnIn2S4 nanosheets, which is favorable to the photocatalytic H2 evolution. This work provides valuable guidance for designing S-scheme heterojunction photocatalysts composed of two n-type semiconductors for energy and environmental applications.

All the Authors:Peng Zhang

First Author:Meng Dai

Indexed by:Journal paper

Correspondence Author:Zuoli He,Xin Li,Shuguang Wang

Volume:122

Page Number:231-242

Number of Words:6000

Translation or Not:no

Date of Publication:2022-03-01