In-situ “encapsulation” of Mo:Mo2C with nano-mosaic structure on wood-derived carbon for hydrogen evolution reaction

Coupling metallic and Mo2C phases uniformly on conductive matrix at nanoscale is a promising route to solve the poor electrical conductivity and aggregation problems of nano-Mo2C. In this work, a 3D self-supporting carbonized wood (CW) electrode encapsulation with mosaic structure Mo:Mo2C for hydrogen evolution reaction was fabricated successfully by a facile annealing treatment and a gas-solid reaction. The presence of Mo phase accelerated the transfer rate of electrons and provided heterogeneous interface. The obtained electrode shows abundant catalytic active sites and low electrochemical impedance, thus improving the catalytic process of splitting water for HER. The Mo:Mo2C-775 electrode requires an overpotential of 73.5 mV and 117 mV to achieve the current density of 10 mA cm−2 in 0.5 M H2SO4 and 1.0 M KOH, respectively. Moreover, Mo:Mo2C-775 electrode displayed excellent stability performance, which almost maintained a constant current density for 12 h (at −100 mV vs RHE) in 0.5 M H2SO4 and 1.0 M KOH, respectively. This study provides a new idea for preparation of efficient 3D self-supporting electro-catalyst for HER.