Self-reconfiguration of catalyst surface to CoNiOOH for efficient overall water splitting

Abstract

Rational doping of heteroatoms is expected to exhibit durable and efficient performance in alkaline electrocatalytic hydrolysis reactions. In this study, a highly stable catalyst with a sandwich structure was successfully prepared by doping a low amount of ruthenium (Ru) nanoparticles on the surface of nickel foam (NF) and further covered with CoMoO₄. Thereafter, activated Co(Ni)OOH-MoO₃-Ru₂₀/NF-C/A electrodes are prepared via electrochemical self-assembly. The resulting electrode exhibited excellent electrochemical performance in a bifunctional catalytic system, and a continuous hydrolysis reaction for 100 h was achieved at constant current densities of 10 mA cm^-2 and 100 mA cm^-2 with operating voltages of 1.538 and 1.82 V, respectively, showing good catalytic activity and total hydrolytic stability. Moreover, the prepared electrodes show similar activity and stability even when operated in seawater. This study reveals the dynamic evolution law of the active sites of the electrocatalyst during the self-reconfiguration process and its performance regulation mechanism, which provides an important theoretical basis for the development of efficient and stable electrocatalytic systems.