Electrodeposited Ni–Fe alloy as a cost-effective material for harnessing hydrogen via the oxygen evolution and urea oxidation reactions

Abstract

Electrochemical energy conversion for hydrogen production is a crucial method to address the global energy demand. Here, a cost-effective approach for the preparation of a transition metal-based alloy electrode through electrodeposition with composition-modulated binary alloy electrodes is achieved using various electrolyte concentrations. An alloy electrode formed from the synergistic combination of Ni–Fe acted as a dual-path energy conversion anode in two different energy conversion systems, the oxygen evolution reaction (OER) and urea oxidation reaction (UOR). Under the optimal conditions, the Ni₅–Fe₃ alloy electrode consumes 1.48 V and 1.45 V vs. RHE for the OER and UOR, respectively. Evidential information from solar-powered water and urea oxidation with a low cell voltage (1.52 V) supports the feasibility of the prepared electrode materials. A lab scale direct oxidation of human urine has also been conducted and the obtained results are a promising cornerstone for waste-to-energy achievement.