Synthesis of flower-like MoSe2@MoS2 nanocomposites as the high efficient water splitting electrocatalyst

Here we report a highly active catalyst for hydrogen evolution reaction (HER) that is constructed by in situ growth of MoS2 on the surface of MoSe2 nanosheets (MoSe2@MoS2). Compared with either single MoS2 or MoSe2, the MoSe2@MoS2 electrocatalyst exhibits better electrocatalytic activity with a small Tafel slope (60 mV dec−1) and a low onset overpotential (−161 mV). The good HER activity is attributed to its core-shell nanostructure, which can not only efficaciously suppress the aggregation of MoS2 nanosheets, but also generate more active sites and produce a synergistic effect of the two components in the HER. This approach provides an effective pathway to improve HER activity of MoS2 or MoSe2 catalysts and can be used for other two-dimensional semiconductor electrocatalyst.