Synergistic enhancement of hydrogen evolution reaction <i>via</i> N and Ni co-doping in TiO ₂ -modified Pt/C catalysts

Hydrogen production through water electrolysis represents a promising green pathway for future hydrogen generation. The development of catalyst materials capable of lowering the reaction energy barrier is crucial for improving electrolysis efficiency. This study synthesized a series of N and Ni co-doped Pt/TiO₂@C catalysts and systematically investigated the effects of N and Ni incorporation on their structure and electrocatalytic performance. Among them, Pt/TiO₂@1%Ni-N-C exhibited the optimal performance, with an overpotential as low as 84 mV and a Tafel slope of 115 mV dec^-1. Characterization results revealed the uniform distribution of Pt nanoparticles and the presence of an anatase TiO₂ crystalline phase. Increasing the Ni loading significantly enhanced the specific surface area of the catalysts while reducing the average pore size. Furthermore, N doping facilitated the anchoring and stabilization stabilizing of Ni atoms on the support. The strengthened interaction between pyridinic N and Ni atoms promoted the formation of Ni⁺ species, which modulated the electronic structure of surface Ni and served as active sites for HER.