▎ 摘　　要

Hydrogen energy has become one of the most potential sources for replacing fossil fuels due to its environmental friendliness and high energy conversion rate. Electrolyzed water is a hydrogen evolution process with high efficiency, no by-products, and high hydrogen purity. Here, we propose to use ZIF-67 as the precursor to prepare three-dimensional multilayer rGO supported CoS2 quantum dots (CoS2QDs@rGO) through a two-step hydrothermal method and one-step calcinations method. The as-prepared electrocatalyst with maximum exposure of edge active sites is highly efficient for hydrogen evolution reaction (HER), delivering an extremely small Tafel slope of 78 mV dec-1, and prominent durability. Density functional theory (DFT) calculations reveal that decoration of CoS2QDs not only obviously changes Gibbs free energy of hydrogen adsorption (Delta GH*), but also offers more active sites for HER, conspicuous promoting the catalytic activity of as-obtained electrode materials. It can be expected that our CoS2 quantum dots mounted on three-dimensional multilayer rGO with ZIF-67 as the precursor, will provide a novel, high-yield and effective catalytic material for energy conversion applications.