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

Abstract A dual S‐scheme heterojunction of Ta 3 N 5 /Bi 2 O 2 CO 3 /Ta 2 O 5 was synthesized with enhanced photoactivity for MB degradation. The Ta 3 N 5 modification introduces hierarchical pore structures in composite, which is conducive to dye absorption and degradation. Ta 3 N 5 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 Ta 3 N 5 and Bi 2 O 2 CO 3 , 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 ⋅O 2 − and ⋅OH with superior oxidation capability were significantly enhanced in Ta 3 N 5 /Bi 2 O 2 CO 3 composite. MB (20 mg/L) degradation efficiency was enhanced from 55 % of Ta 3 N 5 and Bi 2 O 2 CO 3 in 3 hours to almost 95 % of Ta 3 N 5 /Bi 2 O 2 CO 3 composite. Because Ta 3 N 5 was partly oxidized to Ta 2 O 5 during preparation, a dual S‐scheme heterojunction of Ta 3 N 5 /Bi 2 O 2 CO 3 /Ta 2 O 5 was proposed, which provided an exemplary way of fabricating dual S‐scheme heterojunction involving Ta 3 N 5 and Ta 2 O 5 .