▎ 摘 要
2D graphene is conductor and not a semiconductor. 2D transition-metal dichalcogenides (TMD) is a semiconductor and not a conductor. Preparing 2D composite material that simultaneously possesses both advantages of graphene and TMD has proven to be challenging. In this work, both 2D-WS2/2D-GO and 2D-MoS2/2D-GO composites with few layer thickness are synthesized. The electronic structure indicates a high content of Mo4+ 3d5/2 and W(4+)4f7/2 with lower binding energy in the 2D composite, which is ascribed to partial loss of surface sulfur atoms in 2D composites and the newly formed heteroatomic bond of C-W-S and C-Mo-S. The Schottky junction between 2D-GO and 2D-TMD (2D G-T junction) is established and exhibits obvious photoelectric responses. Superior electrocatalytic properties of the two 2D-composites are attributable to the 2D Schottky Junction between 2D-TMDs and 2D-GO. Interlayer electronic coupling in 2D Schottky Junction (2D G-T junction) activates inert sites on the 2D surface of 2D-TMDs or GO. The power conversion efficiency of dye-sensitized solar cells (DSCs) based on 2D-WS2/2D-GO is 9.54% under standard solar illumination intensity (AM1.5, 100 mW cm(-2)). The value is one of the highest reported efficiencies for DSCs based on Pt-free counter electrodes. Finally, 2D-WS2/2D-GO composites exhibit excellent stability as counter electrode of DSCs.