Nickel supported on Nitrogen-doped biomass carbon fiber fabricated via in-situ template technology for pH-universal electrocatalytic hydrogen evolution

Developing alternatives to noble metal electrocatalysts for hydrogen production via water splitting is a challenging task. Herein, a novel electrocatalyst with Ni nanoparticles disperesed on N-doped biomass carbon fibers (NBCFs) was prepared through a simple in-situ growth process using Ni-ethanediamine complex (NiC) as the structure-directing agent. The in-situ template effect of the NiC facilitated the formation of Ni-N bonds between the Ni nanoparticles and NBCFs, which not only prevented the aggregation and corrosion of the Ni nanoparticles, but also accelerated the electron transfer in the electrochemical reaction, thus improving the hydrogen evolution reaction (HER) activity of the electrocatalyst. As expected, the optimal Ni/NBCF-1-H₂ electrocatalyst exhibited better HER activity over the entire pH range than the control Ni/NBCF-1-N₂ and Ni/NBCF-1-NaBH₄ samples. The HER overpotentials of the Ni/NBCF-1-H₂ electrocatalyst were as low as 47, 56, and 100 mV in alkaline (pH = 13.8), acidic (pH = 0.3), and neutral (pH = 7.3) electrolytes, respectively at the current density of 10 mA cm⁻². Meanwhile, the Ni/NBCF-1-H₂ sample could run continuously for 100 h, exhibiting outstanding stability. This work provides a feasible method for developing efficient and cheap electrocatalysts derived from biomass carbon materials using the in-situ template technology.