Amorphous MoO2 with a porous nanostructure as a highly efficient electrocatalyst for overall water splitting

Designing an economical, superior activity, excellent stability, and earth-rich catalysts is of crucial significance in the progress of electrochemical water splitting and still remains huge challenge to overcome. In this work, amorphous MoO2 with a porous nanostructure as a novel bifunctional electrocatalyst has been prepared by the hydrothermal method. This nanostructure has excellent HER/OER properties, in which the amorphous and porous states have a large number of vacancies and active sites exposed to the electrolyte. The as-prepared sample has been researched in detail via X-ray diffraction (XRD) and transmission electron microscopy (TEM). Electrochemical experiments show that when the current density reaches − 10 mA cm−2, the as-prepared samples need an overpotential of only about − 0.930 V (vs. RHE) in 1 M H2SO4 and − 0.777 V (vs. RHE) in 1 M KOH for HER, respectively. Furthermore, MoO2 exhibits an extremely overpotential of 2.414 V (vs. RHE) at 10 mA cm−2 in 1 M KOH for OER. It is believed that the amorphous and porous nanostructure remains a promising and efficient hydrolytic electrocatalyst.