Interface-engineered 1T/2H-MoS2 on 3D nickel foam enables accelerated hydrogen evolution kinetics

Abstract

We report a single-step pulsed electrodeposition strategy that grows mixed-phase 1T/2H-MoS 2 conformally on a porous nickel foam (NF) scaffold, yielding a self-supported MoS 2 /NF electrode. In 1.0 M KOH, MoS 2 /NF requires only an overpotential of −52 mV to deliver −10 mA cm −2 and exhibits a Tafel slope of 77 mV·dec −1 , consistent with a Volmer–Heyrovsky pathway, together with the highest double-layer capacitance of 22.8 mF cm −2 , the lowest charge-transfer resistance, a turnover frequency of 0.91 s −1 at − 0.4 V vs. RHE, and a Faradaic efficiency of 60.8 % among the tested non-noble electrodes. Substrate-controlled experiments on bare Ni and ITO isolate the dual contribution of the 3D NF architecture and the mixed-phase MoS 2 . A volcano plot places MoS 2 /NF near the thermoneutral apex (ΔG H* ≈ −0.16 eV), and the electrode retains ∼ 97 % of its activity after 1000 cycles and 30 h of continuous operation, establishing pulsed electrodeposition as a scalable route to durable, self-supported MoS 2 -based HER electrodes.