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 CuBi₂O₄@Cu₂WS₄ 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 photothermal effect, S-Cu–O bonding and the internal electric field promoted the transport of photogenerated carriers. Visible light irradiation enables a degradation rate of 81.8 % for TC and 67.6 % for LVF in the photothermal-PDS system using Cu₂WS₄/CuBi₂O₄, 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 Ecological Structure Activity Relationships (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.