AgBr/TiO2/g-C3N4 ternary composites with dual Z-scheme heterojunction for efficient removal of organic dye

TiO2 nanosheets with exposed (001) facets synthesized via the hydrothermal method were coupled with g-C3N4 via ball milling. Based on TiO2/g-C3N4 (TC) heterojunction, AgBr/TiO2/g-C3N4 (ATC) ternary composites were obtained through an in-situ deposition-precipitation method. The ATC catalyst demonstrated excellent photocatalytic activity compared to individual components. The degradation efficiency of Rhodamine B (RhB) over ATC catalyst with AgBr content of 60 wt% reached 99.7 % within 30 min. The composites exhibited outstanding photocatalytic efficiency resulting from the heterojunction among AgBr, TiO2, and g-C3N4 which significantly decreased the electron-hole pair recombination rate. The trapping experiments indicated that superoxide radicals and holes were the primary active species involved in RhB removal. The charge transfer mechanism was analyzed in accordance with the energy band structure, revealing a double Z-scheme heterojunction.