Cs-Cu-Cl perovskite quantum dots for photocatalytic H2 evolution with super-high stability

Metal halide perovskites with broad optical absorption and long carrier lifetime are considered as ideal photocatalysts. However, their poor stability in water greatly impedes their application in photocatalytic H 2 evolution because they lose their crystalline structure in water. Herein, we proclaim a new class of photocatalysts: all-inorganic Cs-Cu-Cl perovskite quantum dots (QDs). It exhibits a high photocatalytic hydrogen production rate of ∼ 3.1 mmol/g/h without any cocatalyst under AM 1.5-G solar irradiation (100 mW/cm 2 ). Especially, it remains the high activity for up to 330 h without apparent deterioration of the hydrogen production rate. Density functional theory (DFT) calculations reveal that the Cu site works as the electron and proton absorption sites as the H 2 production active center. To our best knowledge, there is no report of metal halide perovskites as water-stable photocatalysts. This work opens an innovative way for guiding the exploration of metal halide perovskites photocatalysts for stable photocatalytic H 2 evolution.