In situ construction of Z-type defective Al2O3/BiPO4 for efficient photocatalytic degradation of organic dyes

Abstract

In this study, we synthesize an Al2O3/BiPO4 heterojunction via a straightforward in-situ coprecipitation technique. An examination of the catalyst specimen reveals that Al2O3 nanoparticles are uniformly distributed on the surface of the hexagonal BiPO4, achieved through the formation of sturdy chemical bonds. This process leads to the creation of an Al2O3/BiPO4 heterojunction with an elevated concentration of oxygen vacancies. This, in turn, contributes to a notable decrease in the photocatalyst's energy band gap while enhancing the absorption spectrum for visible light. Additionally, the Al2O3/BiPO4 complex showcases a unique internal electric field, giving rise to a direct Z-type heterostructure. This heterostructure can drive the selective migration of photogenerated electrons and holes, achieve effective separation of photogenerated charges under the synergistic effect of oxygen vacancies, and maintain the strong redox abilities of BiPO4 and Al2O3. Consequently, there has been a marked improvement in the efficiency of photocatalytic degradation of organic pollutants in dyes.