Ru-induced electronic structure modulation of NiSnSe@GO boosted oxygen and hydrogen evolution reaction under alkaline...

The development of efficient bi-functional electro-catalysts for overall water splitting is crucial for sustainable hydrogen production. In this study, Ru-induced electronic structure modulation is employed to enhance the bi-functional performance of a NiSnSe@graphene oxide (GO) nanocomposite. Ru-NiSnSe@GO catalysts with varying Ru dopant concentrations (0.1%, 0.5%, and 1%) were synthesized via a hydrothermal route, followed by electrode fabrication through drop-casting the catalyst ink onto nickel foam. Structural and interfacial coupling were verified by SEM/EDS and elemental mapping (homogeneous distribution of Ni, Sn, Se with dispersed Ru on GO sheets), while XRD peak shifts to higher 2θ and Raman band shifts (including G-band red-shift from 1572 to 1565 cm^-1 at higher Ru loading) evidenced lattice contraction and enhanced charge transfer between the selenide phase and GO. Electrochemical evaluation in alkaline media demonstrated a clear dopant-dependent improvement, with the 1% Ru-NiSnSe@GO exhibiting the best activity with an OER overpotential of 290 mV at 50 mA cm^-2 with a reduced Tafel slope of 95 mV dec^-1, and an HER overpotential of 210 mV at 10 mA cm^-2 with a Tafel slope of 153 mV dec^-1. The optimized catalyst also showed increased electrochemically active surface area (C _dl = 0.850 mF; ECSA = 21.25 cm²) and markedly lower charge-transfer resistance (R _ct ≈ 3.2 Ω), supporting faster interfacial kinetics. Overall, synergistic integration of Ru doping with a GO-supported NiSnSe framework provides a practical strategy to boost alkaline OER/HER performance through concurrent active-site enrichment, electronic modulation, and improved conductivity.