Visible-light-driven Z-scheme Bi2Sn2O7/CuBi2O4 heterojunction photocatalysts for the degradation of methylene blue and rhodamine B dyes

Degrading the organic compounds using the photocatalysis is a potential technology to control the environmental pollution. Concerned with this problem, a one-step hydrothermal approach was used to synthesise novel (1-x)Bi2Sn2O7-xCuBi(2)O(4) heterojunctions (where x = 0.05, 0.10, 0.15 and 0.20 wt.%). The compounds were investigated using XRD, FESEM, EDX, HRTEM, XPS, FTIR, UV-DRS, BET, EIS and PL techniques. The degradation of methylene blue (MB), rhodamine B (Rh B) and phenol were used to examine the photocatalytic activity (PCA) of Bi2Sn2O7-CuBi2O4 heterojunctions. 0.90Bi(2)Sn(2)O(7)-0.10CuBi(2)O(4) heterojunction exhibited the highest PCA than pure Bi2Sn2O7 and CuBi2O4. The enhanced specific surface area and the improved charge separations were primarily accountable for the enhanced PCA of these heterojunctions. The plausible mechanism of high PCA of these heterojunctions was comprehensively understood through the precisely computed energy band potentials and the performed free-radical trapping experiments. The trapping investigations showed that h(+ )and O-2(<middle dot>-) play important roles, with O-2(<middle dot>-) being the most prominent species. After four cycles, the heterojunction still effectively degraded the contaminants.