In situ construction of CuBi2O4/Bi4O5Br2 Z-scheme heterojunction with enhanced photocatalytic degradation performance for polyphenolic contaminant in wastewater

Photocatalytic technique is one of the clean and promising routes for wastewater purification. In this work, a different CuBi 2 O 4 /Bi 4 O 5 Br 2 Z-scheme heterojunction were successfully prepared via an in-situ mechanical agitation method. The 10 % CuBi 2 O 4 /Bi 4 O 5 Br 2 (10 % CBO/BOB) heterojunction showed the highest photocatalytic degradation activity for catechin, and ∼99.8 % catechin was degrade within 40 min visible light stimulation, which is (0.0757/min) about 6.2-folds and 8.8-folds to that of Bi 4 O 5 Br 2 (0.0122/min) and CuBi 2 O 4 (0.0086/min), The pH = 7 is the optimal reaction condition for catechin degradation. Besides, The photocatalytic degradation capacity of the 10 % CBO/BOB heterojunction displayed the positive and negative relationship to the dosage of catalyst and initial concentration of catechin, respectively. The enhanced photocatalytic activity of CuBi 2 O 4 /Bi 4 O 5 Br 2 Z-scheme heterojunction can be ascribed to the improvement of the charge separation and light utilization rate. The results of ESR and trapping experiments revealed that the ·O 2 − , h + and ·OH are the primarily reactive substances for catechin degradation. Additionally, the transfer pathway of the photogenerated charges in the CuBi 2 O 4 /Bi 4 O 5 Br 2 Z-scheme heterojunction as revealed by the ESR, Mott-Schottky curve and UV–Vis diffuse reflectance absorption spectroscopy. This work provide a new idea for designing and preparing the novel Bi 4 O 5 Br 2 -based photocatalyst for TCM wastewater purification.