Molybdenum carbides embedded on carbon nanotubes for efficient hydrogen evolution reaction

•Mo2C embedded on CNT are successfully prepared via a simple two-step method.•The optimized hydrothermal and post-annealing temperature is investigated in detail.•Electrocatalytic performance of the catalysts is investigated in both acid and alkaline media.•The superior activity is attributed to high electric-conductivity and small sizes.

Molybdenum carbides embedded on carbon nanotubes are prepared via a simple hydrothermal method with subsequent post-treatment at high temperature. In order to optimize the electrocatalytic activity for hydrogen evolution reaction (HER), effects of hydrothermal and post-annealing temperature are systematically investigated. Electrochemical testing results indicated that Mo2C/CNT prepared at a solvothermal temperature of 200 °C and 800 °C post heat-treatment exhibits the best HER activity with an overpotential of 125 mV in acid media and 93 mV in alkaline media at a current density of 10 mA cm− 2. Such enhanced catalytic activity may originate from high electro-conductivity and ECSA value, together with ultra-small particle size, which accelerates the electron transfer rate and provides large surface area and active sites, respectively.

Graphical abstractMolybdenum carbides with small particle size embedded on carbon nanotubes with optimized experimental condition are prepared via simple hydrothermal method with subsequent post-treatment at high temperature which exhibits the excellent HER activity and stability in acid and alkaline media.Download high-res image (175KB)Download full-size image