N-p heterojunction Bi4O5I2/Fe3O4 composites with efficiently magnetic recyclability and enhanced visible-light-driven photocatalytic performance

Abstract In this investigation, a series of n-p heterojunction Bi4O5I2/Fe3O4 binary composites with a strong magnetic feature and satisfactory photocatalytic performance were reported for the first time. As-synthesized binary composites were thoroughly characterized by various analytical techniques. Both components were combined to generate n-p heterojunction structures confirmed by HRTEM observation and electrochemical analyses. These Fe3O4-containing hybrid composites exhibited enhanced photocatalytic removal abilities upon colorless bisphenol A under visible light irradiation, mainly attributing to improved visible light harvesting, and formation of heterojunction structures together with suitable phase composition and enlarged specific surface areas. In addition, the role of Fe3O4 as a p-type semiconductor was also indicated. These binary composites showed favorable reusability and strong magnetic feature for samples separation. Eventually, a preliminary photocatalysis mechanism was proposed basing on active species trapping results. The strengthened catalytic activities, satisfactory reusability, and favorable magnetic merit guaranteed these composites of potential applications in environmental protection and energy conversion fields in near future.