Unravelling the Role of Strong Metal–Support Interactions in Boosting the Activity toward Hydrogen Evolution Reaction on Ir Nanoparticle/N-Doped Carbon Nanosheet Catalysts

Pt-based catalysts are commercial electrocatalysts for the hydrogen evolution reaction (HER), but their shortcomings of expensive and imperfect efficiency hinder their large-scale application. Here, we report an Ir-based HER catalyst supported by N-doped carbon nanosheets (Ir-NCNSs). The NCNSs, with a high surface area and unique atomic composition, enable Ir nanoparticles (NPs) to disperse at 2–3 nm and strongly coordinate to the Ir through Ir–N bonds, which exposes many active sites and strengthens their durability. The catalyst displays a low overpotential and a small Tafel slope of 46.3 mV at 10 mA cm–2 and 52 mV dec–1 in 0.5 M H2SO4, respectively. When used in 1.0 M KOH, Ir-NCNSs also show excellent electrocatalytic activity with a low overpotential of 125 mV at 10 mA cm–2. The calculated results further suggest that Ir NPs and NCNSs have excellent selectivity for strong metal–support interactions, corresponding to a significant and stable HER characteristic. Our findings provide insight into the design of high-efficiency Ir-based HER catalysts.