Synergistic photocatalytic degradation of TC-HCl by MIL-53(Fe)/CoWO4 composite and PMS under visible light

A series of novel MIL-53(Fe)/CoWO 4 composites were synthesized by combining MIL-53(Fe) and CoWO 4 nanoparticles via solvothermal method. The structural characterizations showed that CoWO 4 nanoparticles were uniformly distributed on the surface of hexagonal bipyramid MIL-53(Fe). Combining XPS and Mott-Schottky plots, a Z-scheme heterojunction was formed between MIL-53(Fe) and CoWO 4 , resulting in a significant improvement in the electron-hole pair separation efficiency. UV–vis diffused reflectance spectra indicated that the optical arrange of MIL-53(Fe)/CoWO 4 composites were expanded to visible light. The photocatalytic degradation experiments under visible light irradiation showed that MIL/CWO-60 synergistically with PMS degraded 90.5 % of TC-HCl within 50 min. The XRD spectra of used and unused composites were identical, indicating good stability in four consecutive cycles. Electron paramagnetic resonance (EPR) and free radicals trapping experiment revealed that active species included O 2− , SO 4 − , h + , OH and 1 O 2 , and mechanism of the synergistic degradation of TC-HCl by MIL-53(Fe)/CoWO 4 composites and PMS was proposed.