MoS2-2xSe2x 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 (MoS2-2xSe2x) nanosheets by hydrothermal synthesis. The HCSs reduced the agglomeration of MoS2-2xSe2x 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, MoS2-2xSe2x-decorated samples revealed enhanced electrocatalytic activity. The composition of MoS2-2xSe2x 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 MoS2-2xSe2x nanosheets (C@MoS2-2xSe2x) revealed the lowest overpotential and the smallest Tafel slope.