Self-derivation High-Mechanical-Strength Polymetallic Phosphides Microsheets Heterostructures for Industrial-scale High Current Density Water Splitting

Abstract

Developing nanoarray microstructure catalysts to amplify catalytic active sites had been a prevalent strategy to achieve effective water electrolysis. However, the stability of electrodes was severely affected by the bubble bombardment at industrial condition. To address this issue, we synthesized the Fe-CoNiP/NCF (Fe-CNP/NCF) bifunctional catalyst with heterogeneous microsheet arrays on nickel cobalt foam (NCF) using Fe3+ as inducer through cation exchange and low-temperature phosphorization methods. The optimized Fe-CNP/NCF catalyst exhibited outstanding HER (η1000=195 mV) and OER (η1000=278 mV) activities, benefiting from the integration of abundant active sites on the hierarchical microsheets, where the doping of Fe promoted the formation of active species for OER. Particularly, accelerated mechanical strength tests demonstrated that the self-derivation multidimensional catalyst possessed high mechanical robustness, ensuring the electrode resistance to withstand bubble impact under high current densities. As a proof of concept, in industrial environment (6 M KOH, 80°C), the dual-electrolyzer assembled with Fe-CNP/NCF sustained electrolysis for 200 hours at a current density of 0.5 A cm-2, with a minimal voltage loss rate of merely 1.5×10-4 V h-1, demonstrating prolonged catalytic durability and structural integrity. This work provided new insights and approaches for developing high mechanical strength nanoscale catalysts for large-scale industrial water electrolysis.