Wafer‐Scale and Low‐Temperature Growth of 1T‐WS₂ Film for Efficient and Stable Hydrogen Evolution Reaction

Abstract

Abstract The metallic 1T phase of WS 2 (1T‐WS 2 ), which boosts the charge transfer between the electron source and active edge sites, can be used as an efficient electrocatalyst for the hydrogen evolution reaction (HER). As the semiconductor 2H phase of WS 2 (2H‐WS 2 ) is inherently stable, methods for synthesizing 1T‐WS 2 are limited and complicated. Herein, a uniform wafer‐scale 1T‐WS 2 film is prepared using a plasma‐enhanced chemical vapor deposition (PE‐CVD) system. The growth temperature is maintained at 150 °C enabling the direct synthesis of 1T‐WS 2 films on both rigid dielectric and flexible polymer substrates. Both the crystallinity and number of layers of the as‐grown 1T‐WS 2 are verified by various spectroscopic and microscopic analyses. A distorted 1T structure with a 2 a 0 × a 0 superlattice is observed using scanning transmission electron microscopy. An electrochemical analysis of the 1T‐WS 2 film demonstrates its similar catalytic activity and high durability as compared to those of previously reported untreated and planar 1T‐WS 2 films synthesized with CVD and hydrothermal methods. The 1T‐WS 2 does not transform to stable 2H‐WS 2 , even after a 700 h exposure to harsh catalytic conditions and 1000 cycles of HERs. This synthetic strategy can provide a facile method to synthesize uniform 1T‐phase 2D materials for electrocatalysis applications.