Bi-axial grown amorphous MoSx bridged with oxygen on r-GO as a superior stable and efficient nonprecious catalyst for hydrogen evolution

Amorphous molybdenum sulfide (MoS x ) is covalently anchored to reduced graphene oxide (r-GO) via a simple one-pot reaction, thereby inducing the reduction of GO and simultaneous doping of heteroatoms on the GO. The oxygen atoms form a bridged between MoS x and GO and play a crucial role in the fine dispersion of the MoS x particles, control of planar MoS x growth, and increase of exposed active sulfur sites. This bridging leads to highly efficient (−157 mV overpotential and 41 mV/decade Tafel slope) and stable (95% versus initial activity after 1000 cycles) electrocatalyst for hydrogen evolution.