Rhenium induced electronic structure modulation of Ni3S2/N-doped graphene for efficient trifunctional electrocatalysis

Herein, we develop a free-standing trifunctional and durable electrocatalyst integrating the Re-doped Ni3S2 nanoarray on N-doped graphene (NG) modified nickel foam substrate (Re–Ni3S2/NG/NF). Particularly, Re-doping is proven to modify the local electronic structure, increase the electroactive surface area, and optimize the adsorption energies of Ni3S2, greatly enhancing trifunctional activities. Accordingly, the water electrolyzer based on the symmetric Re–Ni3S2/NG/NF electrodes achieves a small cell voltage of 1.58 V at 10 mA cm−2 and high Faradaic efficiency of ∼97%, exceeding Pt/C + IrO2 counterpart. Moreover, the rechargeable Zn–air battery with the Re–Ni3S2/NG/NF leads to achieve a high power density of 99 mW cm−2 and round-trip efficiency of 71.2% with a long term stability of 5000 cycles. Taking full potential of Re–Ni3S2/NG/NF electrocatalysts used as “all-in-one” electrode, a real-life operation of self-powered water splitting system is demonstrated for practical applications into highly efficient and multifunctional renewable energy systems.