Cobalt molybdenum oxide/ sponge-like nitrogen and sulfur co-doped carbon composite as a bifunctional electrocatalyst for overall water splitting in alkaline media

Developing highly efficient, stable, cost-effective, and earth-rich bifunctional electrocatalysts for overall water splitting (OWS) is crucial for achieving large-scale hydrogen (H2) production. Herein, we report a cobalt molybdenum oxide/sponge-like nitrogen and sulfur co-doped carbon composite (CoMoO4/N, S co-doped carbon) as an effective bifunctional electrocatalyst for OWS. The CoMoO4/N, S co-doped carbon composite was prepared by a facile hydrothermal process, which exhibited a superior electrocatalytic activity toward both oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). Remarkably, the CoMoO4/N, S co-doped carbon possessed low overpotentials of 220 and 89 mV for OER and HER at a current density of 10 mA cm- 2, respectively. Besides, the assembled CoMoO4/N, S co-doped carbon || CoMoO4/N, S co-doped carbon only required a cell voltage of 1.54 V to reach a current density of 10 mA cm-2 and also revealed significant durability in alkaline media for over 18 h. The high catalytic activity of the CoMoO4/N, S co-doped carbon is benefited from N and S co-doping into the carbon structure along with the simultaneous presence of metal species in CoMoO4. This ensures several electroactive sites in the CoMoO4/N, S co-doped carbon composite, resulting in an outstanding catalytic activity for OWS. Thus, the successful development of non-precious metal and carbonaceous materials opens up a new opportunity to design cost-effective electrocatalysts for the OWS.