Nickel single atom-decorated carbon nanosheets as multifunctional electrocatalyst supports toward efficient alkaline hydrogen evolution

Tailoring catalysts with balanced adsorption capabilities toward multiple reaction intermediates is highly desirable for complex electrocatalytic reactions, but rather challenging. Here, Ni single atom-decorated carbon nanosheets are developed as multifunctional supports for engineering heterostructured electrocatalysts toward hydrogen evolution in alkaline media. The Ni single atoms (Ni–N4) are actively dedicated to cleaving the H–OH bonds as well as facilitating Had spillover to metallic Pt sites. For the case of supported Pt electrocatalysts, a Pt/PtOx configuration is generated at the heterointerface via Pt–O–C (Ni) interfacial bonding, with oxidized Pt species located at the interface and metallic Pt formed in the near-interface area. Further, the oxidized Pt species are also active for boosting the water dissociation step. These findings not only open up a new avenue toward the development of multifunctional catalyst supports but also demonstrate the importance of regulating interface chemistry of heterostructured electrocatalysts at atomic level. A transition metal functionalization strategy was successfully demonstrated toward the development of multifunctional carbon nanosheets as the electrocatalyst supports for alkaline HER. In the case of functionalization with Ni single atoms, the synergistic effect triggered by Ni functionalization and unique heterointerfaces substantially promote the alkaline HER kinetics. [Display omitted] •A transition metal functionalization strategy is proposed toward the development of multifunctional carbon nanosheets.•Ni single atom-decorated carbon nanosheets are demonstrated to be multifunctional supports for hydrogen evolution in alkaline media.•Pt/PtOx configuration is formed at the heterointerface via Pt–O–C (Ni) interfacial bonding.•Ni–N4, oxidized Pt, and metallic Pt species trigger a synergistic effect toward fast hydrogen evolution kinetics.