Lower oxygen vacancy concentration in BiPO4 with unexpected higher photocatalytic activity

Defect engineering has been demonstrated to be an appealing strategy to boost the photocatalytic ac-tivity of materials. However, can higher defect concentration bring about higher photocatalytic activity? This is an open question. In this work, BiPO4 photocatalysts with controllable oxygen vacancy concen-trations were successfully synthesized. The photocatalytic activity of the obtained BiPO4 photocatalysts was determined by the removal of ciprofloxacin and 4-chlorophenol, as well as CO2 photoreduction. The BiPO4 materials with lower oxygen vacancy concentration could display unexpected higher photocatalytic efficiency. Through the investigation of different factors which may affect the photocatalytic performance, such as crystal structure, morphology, specific surface area, defect, and energy band structure, it can be found that the energy band structure difference was responsible for the enhanced photocatalytic activity. (c) 2023 Published by Elsevier B.V. on behalf of Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences.