Fabric-like rhodium-nickel-tungsten oxide nanosheets for highly-efficient electrocatalytic H₂ generation in an...

Transition-metal based oxides with custom-designed phases are effective oxygen evolution reaction (OER) electrocatalysts. However, their applications in water splitting are limited because of insufficient catalytic performance in hydrogen evolution reaction (HER) in alkaline media. In this work, we engineer fabric-like rhodium-nickel-tungsten oxide nanosheets (Rh₂O₃-NiWO₄) on plasma-treated nickel foam (PNF) with a one-step hydrothermal approach for potential applications as industry-grade HER electrocatalysts. Benefiting from rich active sites exposed on the heterostructure, low hydrogen binding energy on Rh, and enhanced charge delivery rates, Rh₂O₃-NiWO₄/PNF catalyst exhibits superior HER activity than that achieved by a commercially available Pt/C catalyst. This is evidenced by the fact that the overpotentials of Rh₂O₃-NiWO₄/PNF for delivering current densities of 10 (j₁₀) and 1000 (j₁₀₀₀) mA cm^-2 in 1.0 M KOH are merely 19 and 293 mV, respectively. Meanwhile, the small Tafel slope (18 mV dec^-1) of the optimized catalyst manifests the fast HER kinetics. In addition, Rh₂O₃-NiWO₄/PNF exhibits ultra-stable HER performance, and the current density (j₁₀₀) only decrease 7.69 % after 100 h chronoamperometric curves (I-t) test. The present work provides a new approach for designing high-performance, low-cost 2D electrocatalysts for H₂ production and other clean energy-related applications.