Bismuth-based complex oxides for photocatalytic applications in environmental remediation and water splitting: A review

As an emerging group of visible-light-driven photocatalysts, bismuth-based complex oxides have attracted considerable attention owing to their outstanding photo-oxidation ability and high performance in decomposition of organic contaminants and water oxidation via photocatalytic processes. However, the relatively low level of the conduction band limits their further application in photocatalytic hydrogen evolution and overall water splitting processes. In this paper, three representative and most-studied Bi-based complex oxides of BiOX (X = Cl, Br, l)/BiFeO3/Bi2WO6 are discussed mainly for environmental pollutants degradation and oxygen generation from water splitting. We present a comprehensive overview of their fundamental compositions, electronic structures and synthesis strategies. On the basis of analyzing the structural-property-activity relationships, detailed approaches for enhancement of their photocatalytic performance have been addressed and compared including morphology/facets control, heterostructures construction and introduction of oxygen vacancies. In addition, several techniques such as engineering energy band and building a Z-scheme system have been proposed to modulate the energy band positions of the photocatalysts and overcome the bottleneck to realize overall water splitting into H-2 and O-2 simultaneously. Finally, remarks on the current challenges, research directions and future perspectives are presented to provide guidance for designing and configuring highly efficient solar-light-driven photocatalysts in the field of environmental purification and energy conversion. (C) 2021 Published by Elsevier B.V.

Automated summary

Bismuth-based complex oxides have attracted attention as visible-light photocatalysts, but their low conduction band limits their application in hydrogen evolution and water splitting processes. This paper discusses Bi-based complex oxides for pollutants degradation and oxygen generation, presenting synthesis strategies and approaches for enhancing their performance. Techniques such as energy band engineering and Z-scheme systems are proposed to overcome challenges in achieving overall water splitting.