A facile electroless preparation of Cu, Sn and Sb oxides coated Ti electrode for electrocatalytic degradation of organic pollutants

Guowei Sun; Chan Wang; Wenxiu Gu; Qijun Song

doi:10.1016/j.scitotenv.2020.144908

A facile electroless preparation of Cu, Sn and Sb oxides coated Ti electrode for electrocatalytic degradation of organic pollutants

Sci Total Environ. 2021 Jun 10:772:144908. doi: 10.1016/j.scitotenv.2020.144908. Epub 2021 Feb 2.

Authors

Guowei Sun¹, Chan Wang¹, Wenxiu Gu¹, Qijun Song²

Affiliations

¹ International Research Center for Photoresponsive Molecules and Materials, School of Chemical and Material Engineering, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu Province 214122, PR China.
² International Research Center for Photoresponsive Molecules and Materials, School of Chemical and Material Engineering, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu Province 214122, PR China. Electronic address: qsong@jiangnan.edu.cn.

PMID: 33578158
DOI: 10.1016/j.scitotenv.2020.144908

Abstract

Electrocatalytic degradation of organic pollutants is an encouraging technology for wastewater treatment. To achieve practical application, electrode plate with cost effective fabrication, high catalytic efficiency and long service life is urgently required. This work prepared a CuO-SnO₂-SbO_X electrode on Ti substrate, which is achieved by ultrasonic assisted deposition of Cu layer, followed by electroless deposition of SnSb layer and finalized by calcination at 500 °C. The obtained electrode (Ti/CuO-SnO₂-SbO_X) exhibited high catalytic degradation activity and a high oxygen evolution potential (OEP) of 2.13 V, which is 0.4 V greater than that of the widely recognized Ti/SnO₂-SbO_X electrode. The oxygen evolution reaction (OER) models of active oxygen intermediate adsorption was optimized by density functional theory (DFT) calculations. The results revealed that (1) the ΔG of the OER rate-determining step was raised to 2.30 eV after Cu doping on 101 plane; (2) binding energies of the optimized surface with reactive oxygen species (ROS) were substantially decreased. Furthermore, the as-prepared electrode has a high yield of hydroxyl radical generation as evidenced by terephthalic acid detection. The potential for hydroxyl radical generation was measured to be 1.8 V at pH = 12 and 2.6 V at pH = 2.The catalytic degradation rate of methylene blue (MB) follows pseudo first order reaction kinetics, and the reaction constant K value reached 0.02964 -k/min^-1, twice as much as that obtained from electrodeposition electrode (Ti/Cu/SnO₂-SbO_X). A degradation rate of 94.6% was achieved for MB in 100 min in the first run, and the value remained over 85% in the subsequent 10 runs. At the same conditions, the degradation rate of p-nitrophenol was over 90% in 100 min and complete mineralization was achieved in 4 h.

Keywords: Chemical deposition; Copper doping; DFT simulation; Electrocatalytic oxidation.