Efficient photocatalytic degradation of tetracycline using Z-scheme GCN/ Bi12O17Br2 composites under visible light: Process and mechanism

In this paper, GCN/Bi12O17Br2 photocatalysts with Z-scheme heterojunction was prepared by in-situ growth of Bi12O17Br2 nanosheets on porous cross-layer graphitic carbon nitride (GCN), which were used for efficient and stable tetracycline (TC) degradation. The construction of Z-scheme heterojunction effectively improved the separation efficiency of photogenerated carriers and promote the formation of & sdot;O 2 and & sdot;OH. In addition, ultrathin porous GCN showed a better morphology and structure, which was conductive to exposing more active sites. The results of experiments showed that TC degradation efficiency of 20-GCN/Bi12O17Br2 photocatalysts with good stability could reach 97% under 80 min illumination. Besides, the mechanism of electron transfer was inferred by XPS, valence band and work function, and degradation products and pathways were deduced based on LC-MS. This work provides an effective method for constructing Z-scheme heterojunction between g-C3N4 and bismuth halide to improve photocatalytic degradation performance.