Boosting Photocatalytic CO2 Reduction on CsPbBr3 Perovskite Nanocrystals by Immobilizing Metal Complexes

Abstract

Converting CO 2 into chemical fuels with a photocatalyst and sunlight is an appealing approach to address climate deterioration and energy crisis. Metal complexes are superb candidates for CO 2 reduction due to their tunable catalytic sites with high activity. The coupling of metal complexes with organic photosensitizers is regarded as a common strategy for establishing photocatalytic systems for visible-light-driven CO 2 reduction. While most of the organic photosensitizers generally contain precious metals and are available through onerous synthetic routes, their large-scale application in the photocatalysis is limited. Halide perovskite nanocrystals (NCs) have been considered as one of the most promising light-harvesting materials to replace the organic photosensitizers due to their tunable light absorption range, low cost, abundant surface sites, and high molar extinction coefficient. Herein, we demonstrate a facile strategy to immobilize [Ni(terpy) 2 ] 2+ (Ni(tpy)) on inorganic ligand-capped CsPbBr 3 NCs and to apply this hybrid as a catalyst for visible-light-driven CO 2 reduction. In this hybrid photocatalytic system, the Ni(tpy) can provide specific catalytic sites and serve as electron sinks to suppress electron–hole recombination in the CsPbBr 3 NCs. The CsPbBr 3 -Ni(tpy) catalytic system achieves a high yield (1724 μmol/g) in the reduction of CO 2 to CO/CH 4, which is approximately 26-fold higher than that achieved with the pristine CsPbBr 3 NCs. This work has developed a method for enhancing the performance of photocatalytic CO 2 reduction by immobilizing metal complexes on perovskite NCs. The methodology we present here provides a new platform for utilizing halide perovskite NCs for photocatalytic applications.