Co–MoCx supported on N-doped CNTs for efficient hydrogen evolution reaction under alkaline medium conditions

The water splitting reaction has the potential to be a sustainable and environmentally friendly way of producing hydrogen as a fuel source, which is an important step in reducing our reliance on fossil fuels and mitigating climate change. Currently, most commonly used catalysts for water splitting are based on precious metals such as platinum and iridium, which are expensive and scarce. Therefore, finding new catalysts that are low-cost, abundant and efficient is of great importance for making water splitting economically viable on a large scale. It was found that pairing up Co nanoparticles (NPs) with MoCx boosted the hydrogen evolution reaction (HER) activity by more than 2-fold (η10 = 130 mV, Tafel slope = 156.08 mV dec−1), compared with the pure Co NPs supported on N-doped carbon (η10 = 337 mV) under alkaline medium conditions. Its activity is comparable to those of Pt single-atom catalysts (SACs) supported on a mesoporous carbon matrix. The good activity may be due to the modification of the D-band of Co by Mo doping and the relatively high electrochemically active surface area (ECSA) of 477.25 cm2, which is comparable to those of Ru SAC materials.