One-step synthesis of the 3D flower-like heterostructure MoS2/CuS nanohybrid for electrocatalytic hydrogen evolution

In this work, a facile one-step hydrothermal method was developed to fabricate three types different of nanomaterials: the two-dimension (2D) of MoS2 nanosheets; 3D spherical CuS nanoparticles; and 3D flower-like heterostructure of MoS2/CuS nanohybrid, respectively. The as-synthesized MoS2, CuS and MoS2/CuS were characterized by transmission electron microscopy (TEM), field emission scanning electron microscopy (SEM) and X-ray diffraction (XRD) etc. The morphology of the MoS2/CuS nanohybrid is different from the MoS2 nanosheets and CuS nanoparticles. The hydrogen evolution reaction (HER) activity of MoS2 nanosheets, CuS nanoparticles and MoS2/CuS nanohybrid, were investigated by the Linear Sweep Voltammetry (LSV) and Tafel slope. The HER activity of MoS2/CuS nanohybrid is better than those of MoS2 nanosheets and CuS nanoparticles, which can be attributed to the good electron-transport ability of CuS and the strong reduction ability of hydrogen ions by MoS2. Thus, MoS2/CuS nanohybrid exhibited excellent activity for HER with a small onset potential of 0.15 V, a low Tafel slope of 63 mV dec−1, and relatively good stability. However, the MoS2 nanosheets and CuS nanoparticles respectively shows a bigger onset potential of 0.25 V and 0.35 V, a higher Tafel slope of 165 and 185 mV dec−1. This 3D flower-like heterostructure of MoS2/CuS nanohybrid catalyst exhibits great potential for renewable energy applications.