MoS_2-2Se₂ Nanosheets Grown on Hollow Carbon Spheres for Enhanced Electrochemical Activity

Electrochemical catalysts with high conductivity and low reaction potential are respected. In this paper, hollow carbon spheres (HCSs) were homogeneously coated with Se-doped MoS₂ (MoS_2-2Se₂) nanosheets by hydrothermal synthesis. The HCSs reduced the agglomeration of MoS_2-2Se₂ nanosheets and improved their conductivity. Compared with the MoS₂-modified samples, Se doping increased the interlayer spacing which provided more active catalytic sites and improved the charge transfer. Thus, MoS_2-2Se₂-decorated samples revealed enhanced electrocatalytic activity. The composition of MoS_2-2Se₂ nanosheets was adjusted by changing the ratios of sulfur and selenium precursors. In the case of a Se/S molar ratio of 0.1, the composite of HCS decorated with MoS_2-2Se₂ nanosheets (C@MoS_2-2Se₂) revealed the lowest overpotential and the smallest Tafel slope.