Strong Dipole Moments\nfrom Ferrocene Methanol Clusters\nBoost Exciton Dissociation in Quantum-Confined Perovskite for CO<sub>2</sub> Photoreduction

Perovskite nanocrystals (PCNs) exhibit a significant\nquantum confinement\neffect that enhances multiexciton generation, making them promising\nfor photocatalytic CO<sub>2</sub> reduction. However, their conversion\nefficiency is hindered by poor exciton dissociation. To address this,\nwe synthesized ferrocene-methanol-functionalized CsPbBr<sub>3</sub> (CPB/FcMeOH) using a ligand engineering approach. By manipulating\nthe electronic coupling between ligands and the PCN surface, facilitated\nby the increased dipole moment from hydrogen bonding in FcMeOH molecules,\nwe effectively controlled exciton dissociation and interfacial charge\ntransfer. Under 5 h of irradiation, the CO yield of CPB/FcMeOH reached\n772.79 μmol g<sup>–1</sup>, 4.95 times higher than pristine\nCPB. This high activity is due to the formation of hydrogen-bonded\nFcMeOH clusters on the CPB surface. The nonpolar disruption and strong\ndipole moment of FcMeOH molecules enhance electronic coupling between\nthe FcMeOH ligands and the CPB surface, reducing the surface barrier\nenergy. Consequently, exciton dissociation and interfacial charge\ntransfer are promoted, efficiently utilizing multiple excitons in\nquantum-confined domains. Transient absorption spectroscopy confirms\nthat CPB/FcMeOH exhibits optimized exciton behavior with fast internal\nrelaxation, trapping, and a short recombination time, allowing photogenerated\ncharges to more rapidly participate in CO<sub>2</sub> reduction.