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 H2 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/cm2). 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 H2 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 H2 evolution.