Visible-light-driven peroxymonosulfate activation by robust TiO2-base nanoparticles for efficient removal of sulfamethoxazole

Jianghong Li; Xueding Jiang; Haishan Guan; Zhang Liu; Jiesen Li; Zhifeng Lin; Fuhua Li; Weicheng Xu

doi:10.1016/j.envpol.2023.122150

Visible-light-driven peroxymonosulfate activation by robust TiO₂-base nanoparticles for efficient removal of sulfamethoxazole

Environ Pollut. 2023 Oct 1:334:122150. doi: 10.1016/j.envpol.2023.122150. Epub 2023 Jul 8.

Authors

Jianghong Li¹, Xueding Jiang², Haishan Guan², Zhang Liu³, Jiesen Li², Zhifeng Lin², Fuhua Li², Weicheng Xu⁴

Affiliations

¹ School of Transportation and Civil Engineering, Foshan University, Foshan, 528000, China.
² School of Environmental and Chemical Engineering, Foshan University, Foshan, 528000, China.
³ Division of Environment and Sustainability, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China.
⁴ School of Environmental and Chemical Engineering, Foshan University, Foshan, 528000, China. Electronic address: weichengxu@fosu.edu.cn.

PMID: 37429490
DOI: 10.1016/j.envpol.2023.122150

Abstract

In this study, a novel bimetallic Co-Mo-TiO₂ nanomaterial was fabricated through a simple two-step method, and applied as photocatalyst to activate peroxymonosulfate (PMS) with high efficiency for sulfamethoxazole (SMX) removal under visible light. Nearly 100% of SMX was degraded within 30 min in Vis/Co-Mo-TiO₂/PMS system, and its kinetic reaction rate constant (0.099 min^-1) was 24.8 times higher compare with the Vis/TiO₂/PMS system (0.014 min^-1). Moreover, the quenching experiments and the electronic spin resonance analysis results confirmed that both ¹O₂ and SO₄^•- were the dominant active species in the optimal system, and the redox cycles of Co³⁺/Co²⁺ and Mo⁶⁺/Mo⁴⁺ promoted the generation of the radicals during the PMS activation process. Additionally, the Vis/Co-Mo-TiO₂/PMS system exhibited a wide working pH range, superior catalytic performance toward different pollutants and excellent stability with 92.8% SMX removal capacity retention after three consecutive cycles. The result of density functional theory (DFT) suggested that Co-Mo-TiO₂ exhibited a high affinity for PMS adsorption, as indicated by the length O-O bond from PMS and the E_ads of the catalysts. Finally, the possible degradation pathway of SMX in optimal system was proposed through intermediate identification and DFT calculation, and a toxicity assessment of the by-products was also conducted.

Keywords: Bimetallic; PMS activation; Sulfamethoxazole; Synergistic effect; TiO(2).

MeSH terms

Light
Nanoparticles*
Peroxides / chemistry
Sulfamethoxazole* / chemistry

Substances

titanium dioxide
peroxymonosulfate
Sulfamethoxazole
Peroxides