MoS(2) Nanosheet Arrays Rooted on Hollow rGO Spheres as Bifunctional Hydrogen Evolution Catalyst and Supercapacitor Electrode

MoS(2) has attracted attention as a promising hydrogen evolution reaction (HER) catalyst and a supercapacitor electrode material. However, its catalytic activity and capacitive performance are still hindered by its aggregation and poor intrinsic conductivity. Here, hollow rGO sphere-supported ultrathin MoS(2) nanosheet arrays (h-rGO@MoS(2)) are constructed via a dual-template approach and employed as bifunctional HER catalyst and supercapacitor electrode material. Because of the expanded interlayer spacing in MoS(2) nanosheets and more exposed electroactive S–Mo–S edges, the constructed h-rGO@MoS(2) architectures exhibit enhanced HER performance. Furthermore, benefiting from the synergistic effect of the improved conductivity and boosted specific surface areas (144.9 m(2) g(−1), ca. 4.6-times that of pristine MoS(2)), the h-rGO@MoS(2) architecture shows a high specific capacitance (238 F g(−1) at a current density of 0.5 A g(−1)), excellent rate capacitance, and remarkable cycle stability. Our synthesis method may be extended to construct other vertically aligned hollow architectures, which may serve both as efficient HER catalysts and supercapacitor electrodes. [Image: see text] ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s40820-018-0215-3) contains supplementary material, which is available to authorized users.