A Facile Synthesis Strategy of Supported g‑C<sub>3</sub>N<sub>4</sub> and Molybdenum Disulfide over Co<sub>3</sub>O<sub>4</sub> Spinal Composite Nanostructure: An Excellent Catalyst\nfor HER

To ensure the sustainability of energy, dihydrogen (H<sub>2</sub>) constitutes the best alternative to fossil fuels for a fully renewable\nand clean energy carrier with the highest energy density. The effective\nand abundant electrocatalysis of water is crucial for achieving large-scale\npractical hydrogen evolution. This study introduces a simple and efficient\nmethod for synthesizing a Co<sub>3</sub>O<sub>4</sub>/MoS<sub>2</sub>@g-C<sub>3</sub>N<sub>4</sub> (CMCN) heterostructure catalyst. The\nCMCN composite material has effective hydrogen evolution reaction\n(HER) kinetic activity across several experimental configurations,\nindicating its desirability. The CMCN composite demonstrates exceptional\nperformance in the hydrogen evolution reaction (HER) in 0.5 M H<sub>2</sub>SO<sub>4</sub>, with a minimal overpotential of 122 mV at\na current density of −10 mA cm<sup>-2</sup> and a narrow Tafel\nslope of 49 mVdec<sup>-1</sup>, surpassing pristine Co<sub>3</sub>O<sub>4</sub>, MoS<sub>2</sub>, g-C<sub>3</sub>N<sub>4</sub>, and\nCo<sub>3</sub>O<sub>4</sub>/MoS<sub>2</sub> (CM) composite. The heterostructure\ndesign promotes efficient charge transfer and optimizes the hydrogen\nadsorption/desorption processes. Interestingly, composite catalysts’\nhigh current density and high mass activity ensure exceptional catalyst\nperformance, along with low overpotential, minimal charge transfer,\nand a low Tafel value. This adaptable technique also makes it possible\nto design and create previously unheard-of inexpensive mixed metal\nelectrocatalysts.