Strategy for controlling the morphology and work function of W2C/WS2 nanoflowers

Abstract

Recently, tungsten disulfide (WS2) and tungsten carbide (W2C) have been demonstrated as promising materials in energy conversion and storage applications. In this study, we describe the successful synthesis of W2C and WS2 alloy nanoflowers (W2C/WS2 NFs) via a simple hydrothermal method. Interestingly, the morphology of the W2C/WS2 alloy NFs and their work function can be precisely controlled by adjusting the precursor, reaction temperature, and reaction time. Specifically, the size of the W2C/WS2 alloy NFs was controlled from 100 nm to 1 mu m by changing the reaction time from 2 to 12 h. The lattice constants of the materials calculated following the peak positions and Bragg's law indicate that the strain remained after the co-formation of W2C and WS2. In addition, the work function of the W2C/WS2 alloy NFs could be tuned from 4.31 to 4.95 eV by modulating the synthetic conditions. Therefore, this work provides a simple approach for the fabrication of W2C/WS2 alloy NFs whose morphology as well as work function can be controlled. (C) 2020 Elsevier B.V. All rights reserved.