Dual S‐Scheme Ta3N5/Bi2O2CO3/Ta2O5 With Hierarchical Pore Structures for Enhanced Photodegradation of Dye‐Performance and Mechanism

Abstract

AbstractA dual S‐scheme heterojunction of Ta3N5/Bi2O2CO3/Ta2O5 was synthesized with enhanced photoactivity for MB degradation. The Ta3N5 modification introduces hierarchical pore structures in composite, which is conducive to dye absorption and degradation. Ta3N5 also enhances the light harvesting capability and improves the carrier separation and transfer efficiency of composite due to its superior photoelectrical properties. A S‐scheme heterojunction was proved to be formed between Ta3N5 and Bi2O2CO3, which not only accelerates the carrier separation and transfer efficiency, but also preserves electrons and holes with superior redox capability in composite. Thus, the formation of ⋅O2− and ⋅OH with superior oxidation capability were significantly enhanced in Ta3N5/Bi2O2CO3 composite. MB (20 mg/L) degradation efficiency was enhanced from 55 % of Ta3N5 and Bi2O2CO3 in 3 hours to almost 95 % of Ta3N5/Bi2O2CO3 composite. Because Ta3N5 was partly oxidized to Ta2O5 during preparation, a dual S‐scheme heterojunction of Ta3N5/Bi2O2CO3/Ta2O5 was proposed, which provided an exemplary way of fabricating dual S‐scheme heterojunction involving Ta3N5 and Ta2O5.