Fabrication of Pt nanoparticles on nitrogen-doped carbon/Ni nanofibers for improved hydrogen evolution activity.

Among various methods for acquiring hydrogen fuel, electrocatalytic water splitting is considered to be as one of the most efficient and promising approaches. Pt is regarded as the best electrocatalyst for the hydrogen evolution reaction (HER) during water splitting process, however, the scarcity and costliness of Pt restrict the large-scale practical application. On the other hand, transition metal Ni is abundant in earth and exhibits favorable HER catalytic activity theoretically. In this work, we have demonstrated a facile electrospinning combined with calcination and chemical reduction processes to fabricate Pt nanoparticles loaded on nitrogen-doped carbon/Ni nanofibers (Ni-NCNFs-Pt) as efficient HER electrocatalysts. The as-prepared Ni-NCNFs-Pt not only reduced the usage of noble metal Pt but also revealed an excellent electrochemical activity at all values of pH, including the smaller overpotentials of 47, 22 and 84 mV (at j = 10 mA cm-2) in 0.5 M H2SO4, 1 M KOH and 0.1 M phosphate buffer solution, respectively. In addition, Ni-NCNFs-Pt nanocatalyst displayed an extraordinary low Tafel slope and long durability over a wide range of pH. The remarkable HER performance could be ascribed to the increased electrochemical active surface area through the introduction of Ni nanoparticles, synergistic interactions between Ni and Pt nanoparticles and the introduction of the conductive nitrogen-doped carbon nanofibers (NCNFs) substrate which facilitated the fast electron transport. This investigation provides a potential route to construct efficient and low cost HER electrocatalysts with promising practical applications in renewable energy conversion and storage devices.