One-Pot Synthesis Of Nio/Nicr2o4 Nanostructure As An Efficient Catalyst For Urea Electro-Oxidation In Alkaline Media

The development of exceptionally active and stable electrocatalysts for the urea oxidation reaction (UOR) is a current research topic of interest. In this work, NiO/NiCr2O4 nanocomposites with different CrNi ratios (denoted as NiO/NiCr2O4-m, m = 1, 2, 3) were synthesized by a facile one-pot hydrothermal mothed without any template followed by a thermal treatment in N-2 at 600 degrees C. The NiO/NiCr2O4-2 catalyst exhibited a large electrochemical surface area, which provided numerous accessible active sites and electronic transmission channels for the UOR. At a low catalyst loading of 50 mu g cm(-2), NiO/NiCr2O4-2 electrode delivered a current density of 994 mA cm(-2) mg(-1) (49.7 mA cm(-2)) in an electrolyte of 1.0 M KOH with 0.33 M urea at the potential of +0.5 V vs Ag/AgCl. The catalyst showed excellent redox characteristics and better stability compared to catalysts with other ratios of NiO/NiCr2O4, pure NiO and NiCr2O4 prepared similarly. Benefiting from the synergistic effect of NiO and NiCr2O4, multicomponent catalysts, particularly NiO/NiCr2O4-2, have demonstrated excellent electrocatalytic activities and are considered as promising candidates for direct urea fuel cells. (C) 2020 The Electrochemical Society ("ECS"). Published on behalf of ECS by IOP Publishing Limited.