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

ABSTRACT

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.