Enhancing\nthe Photocatalytic\nPerformance of CsPbBr<sub>3</sub> Nanocrystals through Ferrocene-Assisted\nExciton Dissociation\nand Halide Vacancies

Excited-state interactions at the\ninterfaces of nanocrystals\nplay\na crucial role in determining photocatalytic efficiency. CsPbBr<sub>3</sub> nanocrystals (CPB NCs), celebrated for their exceptional\nphotophysical properties, have been explored for organic photocatalysis.\nHowever, their intrinsic limitations, such as charge carrier recombination\nand stability issues, hinder their full potential. Strategies to enhance\nexciton dissociation, such as complexing CPB NCs with charge-shuttling\nmolecules, have shown promise but remain underexplored for fully realizing\ntheir potential in improving the photocatalytic performance. We coupled\nferrocene carboxylic acid (FcA) with CPB to extract the photogenerated\nholes, leveraging them to oxidize (1,2-dibromoethyl)benzene to phenacyl\nbromide. Optimization using pristine CPB NCs achieved a production\nrate of 5 μmol g<sub>cat</sub><sup>–1</sup> h<sup>–1</sup>, which increased to 13.1 μmol g<sub>cat</sub><sup>–1</sup> h<sup>–1</sup> upon FcA incorporation, marking a 2.5-fold\nenhancement. Mechanistic investigations revealed the simultaneous\ninvolvement of electrons and holes, with oxygen acting as a reactant\ncontributing to the oxygenated product. Halide vacancies were identified\nas critical adsorption sites for the substrate, with post-synthetic\ntreatments enhancing these vacancies, resulting in over a 2-fold increase\nin the reaction rate. This work not only establishes an effective\napproach for phenacyl bromide synthesis but also highlights the potential\nof leveraging dissociated charge carriers to enhance photocatalysis\nusing CPB NCs.