Abstract
Cobalt disulfide (CoS(2)) features highly active catalytic sites and is regarded as a promising candidate for electrocatalytic hydrogen evolution. In this study, molybdenum-doped cobalt disulfide (CoS(2):Mo) was synthesized via a facile hydrothermal approach. XRD analysis confirms that the obtained samples crystallize in a cubic pyrite structure, with diffraction peaks consistently shifting towards lower angles. SEM characterization reveals that the samples exhibit microrod-like morphologies with an average size of approximately 1 μm. Integrated analyses from XRD, XPS, and EDS mapping demonstrate that Mo is uniformly distributed across the surface and successfully doped into the CoS(2) lattice. Electrochemical measurements indicate that the CoS(2):Mo sample delivers a low overpotential of 122 mV and a Tafel slope of 128 mV dec(-1) at a current density of 10 mA cm(-2) in alkaline media, significantly surpassing the performance of pure CoS(2) and MoS(2). Moreover, the CoS(2):Mo exhibits an enhanced double-layer capacitance, with a C(dl) value of 2.72 mF cm(-2), superior to that of pure CoS(2) (1.63 mF cm(-2)) and MoS(2) (0.31 mF cm(-2)). Mo doping enhances conductivity and active sites, thereby boosting electrocatalysis. This work presents an effective strategy for the development of cost-efficient and high-performance non-precious metal electrocatalysts.