Application of Carbon-Based Oxygen Evolution Reaction Electrocatalyst in Zinc Electrowinning System

Electrode polarization potential is an important factor of cell voltage during electrowinning, which can affect the total energy consumption of the zinc hydrometallurgy process. In this work, we creatively use a metal-free oxygen evolution catalyst of water electrolysis to the hydrometallurgy system. An amino-rich hierarchical-network carbon(Amino-HNC) electrocatalyst was prepared by a simple two-step method of amino-assisted polymerization and carbonization process. The surface morphology, phase composition, and electrochemical properties were characterized. The results show that Amino-HNC is an electrocatalyst for oxygen evolution reaction with an amino-rich network structure, and the oxygen evolution overpotential in 0.5 mol L-1 H2SO4 electrolyte is 389 mV (@ 10 mA cm(-2)). Meanwhile, the prefabricated catalyst is directly used as an anode in the zinc electrowinning system (50 g L-1 Zn2+ + 150 g L-1 H2SO4) to measure the cell voltage. Compare with the traditional pure lead anode, the cell voltage decreased in a short time during the zinc electrowinning process.