Generating Long-Lived Charge Carriers in CdS Quantum Dots by Cu-Doping for Photocatalytic CO₂ Reduction

Abstract

Converting CO 2 into high-value-added chemicals has been recognized as a promising way to tackle the fossil fuel crisis. Quantum dots (QDs) have been extensively studied for photocatalytic CO 2 reduction due to their excellent optoelectronic properties. However, most of the photogenerated charge carriers recombine before they participate in the photocatalytic reaction. It is crucial to regulate the charge carriers to minimize undesired charge recombination, thus, promoting surface photocatalysis. Herein, we report a copperdoped CdS (Cu:CdS) QD photocatalyst for CO 2 reduction. Density functional theory simulations and experimental results demonstrate that Cu dopants create intermediate energy levels in CdS QDs that can extend the lifetime of exciton charge carriers. Furthermore, the long-lived charge carriers can be harnessed for the photocatalytic reaction on Cu:CdS QDs. The resultant Cu:CdS QDs exhibited a significantly enhanced photocatalytic activity toward CO 2 reduction compared to the pristine CdS QDs. This work highlights the importance of charge regulation in photocatalysts and opens new pathways for the exploration of efficient QD photocatalysts.

Passivating Defects and Constructing Catalytic Sites on CsPbBr3 with ZnBr2 for Photocatalytic CO2 Reduction

“…In addition, BF 4 – and PF 6 – have been successfully applied to remove the surface defective layer of CsPbBr 3 , ,, resulting in improved photocatalytic activity for CO 2 reduction. For constructing catalytic sites, one of the most efficient methods is incorporating transition metal salts into the host lattice during their growth. − For instance, recent studies have shown that the surface reaction barriers for CO 2 reduction can be easily regulated by doping Fe 2+ , Ni 2+ , or Mn 2+ . ,, These dopants can potentially introduce new energy levels and tune the charge transfer pathways in perovskites . However, simultaneously reducing perovskite surface defects and constructing catalytic sites for targeting reactions remains challenging.…”