Facile route for synthesizing WS2/W2C nano hollow flowers and their application for hydrogen evolution reaction

Abstract

Recently, catalysts based on tungsten disulfide nanoflowers (WS2 NFs) and tungsten carbide (W2C) mate-rials have been intensively investigated for hydrogen evolution reaction (HER). In this study, a facile and scalable route was utilized to synthesize a nano hollow flowers catalyst based on heterostructure of WS2 and W2C (WS2/W2C NHFs). Besides that, other structures of tungsten compounds including WS2-WO3 flower particles (FPs) and pure WS2 NFs were also prepared by the similar route with slight modification, to compare the differences in their structures and HER activities. Materials properties were comprehensively studied via X-ray diffraction analysis, field emission scanning microscopy, Raman spectroscopy, X-ray photoelectron spectroscopy, and transmission electron microscopy. Then, the HER catalytic activities of synthesized materials were also carefully studied. The results indicate that WS2/W2C NHFs exhibits the HER activities much better than that of prepared WS2-WO3 FPs and pure WS2 NFs. The HER performance of WS2/ W2C NHFs exhibits a low Tafel slope of about 61 mV.dec1, an overpotential of - 280 mV at - 10 mA.cm-2, high double-layer capacitance (11.9 mF cm-2) and the superstability in acid media. This improvement is attributed to the synergistic effect of the WS2 and W2C heterostructure as well as the special structure of WS2/W2C NHFs catalyst.(c) 2023 Elsevier B.V. All rights reserved.