A hierarchical and branch-like NiCoS/NF material prepared by gradient electrodeposition method for oxygen evolution reaction

Rational fabrication of high performance electrocatalysts materials is of great significance to efficiently accomplish energy conversion. In this work, taking the advantage of the remarkable features of nickel foam, a holey branch-like structure of NiCoS deposition supported on nickel foam (NF) was obtained via altering the current density in the whole electrolytic process for gradient electrodeposition. Benefiting from the three-dimension porous structure of nickel foam skeleton connected by spherical particles of irregular size and the strong synergistic effect among Ni, Co and S elements, NiCoS/NF only needed overpotential of 287 mV, Tafel slope of 64.74 mV dec−1 and an excellent stability of 25 h in 1.0 M KOH at the current density of 10 mA cm−2 and 100 mA cm−2. Importantly, originated from the interconnected nanoparticles, this branchlike structure and the Co-doping-optimized electronic structure are responsible for the rapidly enlarged ECSA value 19,650 cm−2 of deposition and the TOF value 2.2704 s−1. This work will provide a constructive idea for enhancing the efficiency of hydrogen production through water splitting.