Photothermal-assisted photocatalytic peroxydisulfate activation based on core-shell CuBi2O4@Cu2WS4 modulated by interfacial bonding and internal electric field

Abstract

The photothermal effect, interfacial bond and  internal electric field can effectively regulate the charge transfer of the heterojunction, improving the photocatalytic activity of the catalyst. Herein, we prepared the 1D/2D core-shell Cu2WS4/CuBi2O4 (CWS/CBO) heterojunction with the photothermal effect of “1+1>2”, which can effectively degrade tetracycline (TC) and levofloxacin (LVF) through the photothermal synergistic peroxydisulfate (PDS) activation process. Density functional theory (DFT) calculation femtosecond transient (fs-TAS) spectral and temperature control experiment analysis showed that the migration of photo-generated carriers was promoted through the photothermal effect, S-Cu-O bonding and the internal electric field. Under visible light irradiation, the degradation rate of TC in photothermal-PDS system by CWS/CBO can reach 81.8% and the degradation rate of LVF is 67.6% at 25℃, which is 43.8% and 26.9% higher than that at 10℃, respectively. In addition, the vulnerable sites of TC molecules were determined by calculating the Fukui index. The ecological risk of TC degradation products was predicted based on the ECOSAR model, and the bean sprout cultivation experiment further verified the lower environmental risk of TC degradation products. This study provides a novel and feasible strategy for designing and developing photocatalysts for photothermal synergy PDS advanced oxidation process and organic pollutant degradation.

Keywords: photothermal, Cu2WS4, CuBi2O4, core-shell structure, interfacial chemical bond, peroxydisulfate