Porous β-Mo2C nanoparticle clusters supported on walnut shell powders derived carbon matrix for hydrogen evolution reaction.

Herein, we choose the waste walnut shell as the carbon source, and ammonium heptamolybdate as the molybdenum source to prepare the β-Mo2C catalyst supported on carbon matrix (Mo2C@C) by the calcination method for hydrogen evolution reaction (HER). The open pores in the porous Mo2C nanoparticle clusters can facilitate electrolyte permeation and hydrogen molecules release as well as the carbon matrix can enhance the conductivity. As a result, the optimal Mo2C exhibits an efficient HER performance, with an overpotential of 140 mV at 10 mA cm-2 and a Tafel slope of 63 mV dec-1 as well as excellent electrochemical stability. The strategy changing waste walnut shell into the effective catalysts sets an example for the searching and designing rational energy materials.