2D/2D p‐n Heterojunctions of CaSb₂O₆/g‐C₃N₄ for Visible Light‐Driven Photocatalytic Degradation of Tetracycline

Abstract

Despite many attempts to build g‐C 3 N 4 based heterojunctions there are currently no systematic guidelines for designing such composites. Herein, we rationally designed and synthesized a novel CaSb 2 O 6 /g‐C 3 N 4 2D/2D heterojunction with ideal lattice matching. The as‐synthesized heterojunctions had superior visible light‐driven photodegradation toward tetracycline solution compared with those of pristine g‐C 3 N 4 and CaSb 2 O 6 . The corresponding maximum apparent kinetic rate constant was 0.01388 min –1 , which was approximately 2.4 and 53 times greater than those of g‐C 3 N 4 and CaSb 2 O 6 , respectively. Additionally, photoelectrochemical measurements indicated that the enhanced photocatalytic performance was attributed to generation of an internal electric field by the intimate contact p‐n heterojunction. The main reactive species were · OH, · O 2 – and h – are the dominate reactive species in the photocatalytic process. This study will inspire efforts to build 2D/2D heterojunction photocatalysts with efficient carrier separation and higher photocatalytic performance through structural chemistry or solid state chemistry analysis.