Advancements in heterojunction, cocatalyst, defect and morphology engineering of semiconductor oxide photocatalysts

Photocatalytic technology has emerged as a crucial avenue for harnessing solar energy, presenting itself as a viable solution to address the current energy crisis and environmental pollution. The past 50 years have witnessed significant progress and breakthroughs in scientific research on photocatalytic technology. This paper provides a comprehensive review of the mechanism of photocatalytic technology and methods to improve the photocatalytic efficiency of semiconductor photocatalysts, such as TiO₂ and ZnO. In this paper, common modification methods are divided into four categories: heterojunction construction, cocatalysts, defects, and morphological engineering. The origin and development of photocatalysts in each category are briefly summarized; moreover, the latest progress in each type of modification is discussed. S-scheme heterojunctions retain the high reduction and oxidation capacity of photogenerated electrons and holes by sacrificing half of the photogenerated carriers, showing excellent performance in photocatalysis and great application potential. The challenges associated with current modification schemes are presented. There is growing interest in quantitative and atomic-level modulation as attractive approaches to tackling these challenges. Regulating the electronic spin state and internal field is important for minimizing photogenerated carrier recombination in photocatalysis. This review will inspire researchers and promote the application of photocatalytic technology.