Facile fabrication of Ag/GO/Ti electrode by one-step electrodeposition for the enhanced cathodic reduction of nitrate pollution

Abstract In this work, a composite Ti electrode electrodeposited with graphene oxide (GO) and metal Ag (Ag/GO/Ti) was fabricated by one-step electrodeposition and used as a cathode for nitrate reduction from wastewater. Characterization results showed that GO was successfully deposited on the Ti plate and the size of Ag particles on Ag/GO/Ti was reduced and became more uniform than Ag/Ti. For Ag/GO/Ti electrode, GO middle layer acted a pivotal part in the homogeneous formation of the Ag, and significantly improved the electrocatalytic activity and chemical stability. Based upon the NO3−-N removal efficiency and the selectivity of the N2, optimum reaction condition was achieved with Ag/GO/Ti at an initial NO3−-N concentration of 20 mg/L, current density of 10 mA/cm2, initial pH of 7, initial chloride ion concentration of 400 mg/L, initial NH4+-N concentration of 80 mg/L and using 0.05 mol/L Na2SO4 as electrolyte. About 81.5 % NO3−-N could be converted to N2 through a cathodic reduction and an anodic oxidation cycle.