α(β)-PbO2 doped with Co3O4 and CNT porous composite materials with enhanced electrocatalytic activity for zinc electrowinning

Xuanbing Wang; Ruidong Xu; Suyang Feng; Bohao Yu; Buming Chen

doi:10.1039/c9ra08032e

α(β)-PbO₂ doped with Co₃O₄ and CNT porous composite materials with enhanced electrocatalytic activity for zinc electrowinning

RSC Adv. 2020 Jan 7;10(3):1351-1360. doi: 10.1039/c9ra08032e.

Authors

Xuanbing Wang^{1

2}, Ruidong Xu^{1

2}, Suyang Feng^{1

2}, Bohao Yu², Buming Chen²

Affiliations

¹ State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization, Kunming University of Science and Technology Kunming 650093 China rdxupaper@aliyun.com +86 871 65161278 +86 871 65160072.
² Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology Kunming 650093 China.

Abstract

The high energy consumption during zinc electrowinning is mainly caused by the high overpotential of the oxygen evolution for Pb-Ag alloys with strong polarization. The preparation of new active energy-saving materials has become a very active research field, depending on the synergistic effects of active particles and active oxides. In this research, a composite material, α(β)-PbO₂, doped with Co₃O₄ and CNTs on the porous Ti substrate was prepared via one-step electrochemical deposition and the corresponding electrochemical performance was investigated in simulated zinc electrowinning solution. The composite material showed a porous structure, finer grain size and larger electrochemical surface area (ECSA), which indicated excellent electrocatalytic activity. Compared with the Pb-0.76 wt% Ag alloy, the overpotential of oxygen evolution for the 3D-Ti/PbO₂/Co₃O₄-CNTs composite material was decreased by about 452 mV under the current density of 500 A m^-2 in the simulated zinc electrowinning solution. The decrease in the overpotential of oxygen evolution was mainly ascribed to the higher ECSA and lower charger transfer resistance. Moreover, it showed the lowest self-corrosion current density of 1.156 × 10^-4 A cm^-2 and may be an ideal material for use in zinc electrowinning.