A novel g-CN nanosheet/AgPO/α-BiO ternary dual Z-scheme heterojunction with increased light absorption and expanded specific surface area for efficient photocatalytic removal of TC

A novel ternary dual Z-scheme 2D g-C 3 N 4 nanosheet/Ag 3 PO 4 /α-Bi 2 O 3 (CNN/AP/BO) photocatalyst was successfully synthesized by an in situ deposition and hydrothermal-calcination method. The coupling of AP and BO remarkably enhanced the photocatalytic tetracycline (TC) degradation under visible light illumination, with an optimal removal efficiency of 91.6% (60 min), which can be attributed to the extended visible-light absorption and increased specific surface area owing to the interfacial intimate coupling with well-matched energy band positions between semiconductors. The improved photocatalytic activity resulted from the abundant free radicals by the order of &z.rad;O 2 − > h + > &z.rad;OH based on the electron spin resonance (ESR) and quenching experiment results. In addition, the possible mechanism of TC degradation over the ternary dual Z-scheme heterojunction CNN/AP/BO was proposed. A novel ternary dual Z-scheme photocatalyst g-C 3 N 4 nanosheet/Ag 3 PO 4 /α-Bi 2 O 3 was designed via an in situ deposition and hydrothermal-calcination method with an excellent photocatalytic performance toward TC degradation.