Silk derived electrospun carbon nanofibers loaded with CoS nanoparticles as efficient hydrogen evolution reaction catalysts in acidic and alkaline media

The design of a stable and efficient hydrogen evolution catalyst across the entire pH range is of significant importance for the development of hydrogen production technology by electrocatalytic water splitting. This study chose biomass silk fibroin protein as the electrospinning raw material, synthesizing a hybrid membrane of CoS@carbon nanofibers (CNF) with a layered core–shell structure through simple carbonization and hydrothermal treatment. The CoS nanoparticles can grow uniformly and densely on the CNF. By varying the concentrations of hexahydrate cobalt nitrate (Co(NO3)2·6H2O) and thiourea (CH4N2S), the morphology of the synthesized CoS nanoparticles on CNF can be controlled. Different microscopic morphologies lead to differences in the activity of the hydrogen evolution reaction (HER), attributed to variations in the exposed active sites for different morphologies. Compared to pure CNF, the CoS-2@CNF hybrid membrane exhibits excellent HER activity in both acidic and alkaline electrolytes. This highlights the synergistic catalytic effect between CNF and CoS particles. This work provides guidance for the rational design of bio-based catalysts with excellent performance.