Chemical-vapor-deposition-grown 2D transition metal dichalcogenides: A generalist model for engineering electrocatalytic hydrogen evolution

Two-dimensional (2D) transition metal dichalcogenides (TMDs) have proved to possess exceptional catalytic performance for hydrogen evolution and are considered to be an appropriate substitute for commercial Pt-based catalysts. Experimentally, chemical vapor deposition (CVD) is an extremely important technique for acquiring controllable and high-purity TMDs for electrocatalysis and modern electronic devices. Recently, researchers have made significant achievements in synthesizing TMDs used for electrocatalytic hydrogen evolution by CVD ranging from dynamic mechanism exploration to performance optimization. In this review, we present the recent progress based on electrocatalytic hydrogen evolution implemented by CVDgrowth TMDs nanosheets and unveil the structural-activity correlation. Firstly, in synthesis, diverse factors covering precursor, substrate, temperature settings, and atmosphere will affect the quality and surface morphology of TMDs. Then, we present the current research status of the CVD-grown 2D TMDs for engineering electrocatalytic hydrogen evolution, including intrinsic performance exploring, morphology engineering, composition adjusting, phase engineering, and vertically-oriented structure constructing. Finally, the future prospects and challenges of CVD in 2D TMDs electrocatalysis are provided.