 Metal calcogenide nanomaterials have shown great promise in catalyzing the water-splitting reaction, which can be used to generate clean and renewable energy sources. Various techniques have been developed to optimize the morphologies and structures of these materials, leading to improved catalytic activity. However, there remain several challenges that need to be addressed before this technology can be fully realized. This article was authored by Gain, Jing Jing, Hong Hong Lin, and others.