One-Step Electrosynthesis of Bifunctional NiCu Nanosheets on Iron Foam for Remarkably Enhanced Alkaline Water Splitting

Abstract

Electrocatalytic water splitting for hydrogen production driven by renewable electricity offers a promising way of achieving energy sustainability, but the design of highly efficient and cost-effective electrocatalysts is regarded as a bottleneck. Herein, a bifunctional microflowers NiCu is successfully deposited on an iron foam (IF) electrode via one-step electrolysis of spend cupronickel (SCN). Unexpectedly, the designed IF-supported NiCu (NiCu/IF) electrocatalysts exhibit excellent catalytic performance for oxygen evolution reactions (OER) and hydrogen evolution reactions (HER) in 1 M KOH. Only 98 and 267 mV are required to drive a current density of 10 mA cm−2 for HER and OER, respectively. Importantly, the self-supported NiCu/IF electrode requires a low cell voltage of 1.57 V to achieve 10 mA cm−2 of alkaline overall water splitting with extremely high stability. With the introduction of a glycerol oxidation reaction (GOR), the HER performance is further remarkably enhanced with an extremely low cell voltage of 1.29 V at 10 mA cem−2, highlighting an attractive energy-efficient hydrogen production coupled with biomass conversion process. This study reports a novel synthesis strategy for low-cost and high-performance Ni-based nanostructure catalysts using SCN as precursors, which is of vital significance for green hydrogen production and waste recycling.