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.