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Facile one-pot synthesis of defect-engineered step-scheme WO3/g-C3N4 heterojunctions for efficient photocatalytic hydrogen production

Authors :
Xiya Du
Xingang Li
Tong Ding
Song Song
Yating Wang
Ye Tian
Wenfeng Jin
Source :
Catalysis Science & Technology. 11:2734-2744
Publication Year :
2021
Publisher :
Royal Society of Chemistry (RSC), 2021.

Abstract

Constructing step-scheme (S-scheme) heterojunctions is one of the efficient strategies to enhance photocatalytic processes, but unfortunately their synthesis requires complex procedures. Here, we develop a facile methodology for one-pot synthesis of defect-engineered S-scheme WO3/g-C3N4 heterojunctions. The as-synthesized sample (15.0WCN) exhibits a remarkable photocatalytic hydrogen generation rate (1034 μmol h−1 g−1), which is 1.7 and 4.5 times higher than that of normal S-scheme WO3/g-C3N4 heterojunctions (15.0W + CN) and pure g-C3N4, respectively. We discover that surface oxygen vacancies can improve the separation efficiency of photogenerated carriers by acting as a mediator between the valence band of g-C3N4 and the conduction band of WO3, while bulk oxygen vacancies mainly enhance visible light absorption through narrowing the band gap in the S-scheme system. In addition, our studies show that surface oxygen vacancies are more effective than bulk ones in S-scheme heterojunctions for photocatalytic hydrogen production. This work affords a new insight into coupling strategies of defect-engineering and S-scheme heterojunctions, which is helpful for designing other efficient photocatalytic systems.

Details

ISSN :
20444761 and 20444753
Volume :
11
Database :
OpenAIRE
Journal :
Catalysis Science & Technology
Accession number :
edsair.doi...........6b0571524e482715a6b222272e872a3b