Interfacial Electronic Rearrangement and Synergistic Catalysis for Alkaline Water Splitting in Carbon-Encapsulated Ni (111)/Ni3C (113) Heterostructures

Abstract

The realization of efficient water electrolysis is still blocked by the requirement for a high and stable driving potential above thermodynamic requirements. An Ni-based electrocatalyst, is a promising alternative for noble-metal-free electrocatalysts but tuning its surface electronic structure and exposing more active sites are the critical challenges to improving its intrinsic catalytic activity. Here, we tackle the challenge by tuning surface electronic structures synergistically with interfacial chemistry and crystal facet engineering, successfully designing and synthesizing the carbon-encapsulated Ni (111)/Ni3C (113) heterojunction electrocatalyst, demonstrating superior hydrogen evolution reaction (HER) activities, good stabilities with a small overpotential of −29 mV at 10 mA/cm2, and a low Tafel slope of 59.96 mV/dec in alkaline surroundings, approximating a commercial Pt/C catalyst and outperforming other reported Ni-based catalysts. The heterostructure electrocatalyst operates at 1.55 V and 1.26 V to reach 10 and 1 mA cm−2 in two-electrode measurements for overall alkaline water splitting, corresponding to 79% and 98% electricity-to-fuel conversion efficiency with respect to the lower heating value of hydrogen.

Surface distortion of FeRu nanoparticles improves the hydrogen evolution reaction performance in alkaline media

“…19,33,34 Since catalytic reactions properly occur at the lower coordination atomic sites, such as edges, corners, and kinky sites, the formation of surface vacancies would inevitably present such active sites. 35–42 For instance, Yu and co-workers reported that the strain- and defect-engineered Ni-MoS 2 monolayer exhibits a superior HER performance by promoting the rate-determining water dissociation step. 39…”

“…19,33,34 Since catalytic reactions properly occur at the lower coordination atomic sites, such as edges, corners, and kinky sites, the formation of surface vacancies would inevitably present such active sites. [35][36][37][38][39][40][41][42] For instance, Yu and co-workers reported that the strain-and defect-engineered Ni-MoS 2 monolayer exhibits a superior HER performance by promoting the rate-determining water dissociation step. 39 Inspired by the aforementioned concepts, we designed Rubased alloy nanoparticles (NPs) with a distorted surface structure in order to boost the HER kinetics in alkaline media.…”