Facile synthesis of W2C@WS2 alloy nanoflowers and their hydrogen generation performance

Abstract Two–dimensional transition metal dichalcogenides such as MoS2 and WS2 nanosheets, nanoflowers, and nanoparticles have been investigated as potential materials for the hydrogen evolution reaction (HER). Besides 2D–TMDs, MXene materials, which are transition metal carbides/nitrides, are promising candidates for energy storage and conversion applications. In this work, alloys of tungsten carbides and tungsten disulfides have been fabricated through a facile hydrothermal method without using any complex structure of carbon or polymer source for carbonization. The fabricated alloys were characterized by X-ray diffraction analysis, field emission scanning microscopy, atomic force microscopy, Raman spectra, and X-ray photoelectron spectroscopy. The results indicated both W2C and WS2 have hexagonal structure in the alloy compound. W2C@WS2 nanomaterials exhibit abundant flower-shaped active sites ranging from 200 to 400 nm in size. The catalytic behavior of these alloys in the HER was studied through a three-electrode system. The results indicated that the catalytic performance was better than those of previous research and that the flower-shaped nanomaterials were superior to nanosheets, with a high double-layer capacitance of 12 mF cm−2. This work, thus, introduced a simple approach to the synthesis of transition metal carbide/chalcogenide composites and demonstrated that these materials are promising in energy generation and storage applications.