Synthesis of monodisperse water-stable surface Pb-rich CsPbCl3 nanocrystals for efficient photocatalytic CO2 reduction

Abstract

Surface Pb-rich lead halide (CsPbCl₃) perovskite nanocrystals (NCs) with high stability and monodispersity in water have been synthesized using a general and convenient liquid–solid interpenetration (LSI) method. In this process, water molecules permeate into the solid CsPbCl₃ NC layers and slowly dissolve the Cs⁺ and Cl⁻ ions on the surface of CsPbCl₃ NCs. The Cs⁺ and Cl⁻ ions in water inhibit the decomposition rate of CsPbCl₃ NCs, inducing surface Pb-rich layers. The surface Pb-rich structure increases the photoluminescence (PL) lifetimes and improves the photocatalytic performances of lead halide perovskite NCs. Under simulated solar irradiation, the largest rate of CO₂ photoreduction from surface Pb-rich Ni-doped CsPbCl₃ NCs reaches up to 169.37 μmol g⁻¹ h⁻¹. This study provides an effective general strategy to design stable lead halide perovskite quantum dots (QDs) for their wide applications.