An exploration of the electrocatalytic activity of urea-activated cobalt oxalate for kinetic promotion of the oxygen evolution reaction

Abstract

The search for an effective oxygen evolution reaction (OER) catalyst using a sustainable and simple preparative method is still ongoing. High stability and low overpotential with better kinetics are the primary features to consider while constructing an effective catalyst. Here, we have developed an effective route to synthesize urea-activated cobalt oxalate (UCoOx) via a precipitation method at 50 °C, which needs 321 mV to attain 10 mA cm⁻² with a small Tafel slope of 78 mV dec⁻¹. Further, it exhibited 80 h of chronopotentiometric stability with 95% Faradaic efficiency in 1 M KOH. The small amount of urea component reduced the overpotential by 68 mV compared to CoOx and also increased charge transfer migration by lowering the resistance by 2.5 Ω. The geometric and intrinsic activities of UCoOx revealed a paradigm shift in catalytic efficiency. A solar-driven electrolyzer confirmed the practical application of UCoOx/NF (1.57 V) for the industrial production of H₂. As a result, the cost-effective UCoOx performance presents a promising way to increase the performance of cobalt-based catalysts in renewable energy resources.