Efficient and Selective Photocatalytic Co2 Reduction Over Ga Single Atoms Decorated Quantum Dots Under Visible Light

Abstract

Exploring unique single atoms as catalytic sites is vitally important to improving the activity and selectivity of photocatalytic CO2 reduction but remains challenging. Here, we find that Gallium (Ga) single atoms can serve as effective active sites for boosting the photocatalytic CO2 reduction reaction over CdSe quantum dots (QDs). Specifically, Ga single atoms decorated CdSe QDs exhibit the CO evolution rate of 16.1 μmol h-1 and selectivity of 90.4% with excellent durability over 30 hours, which are much higher than those of bare CdSe QDs. The mechanism investigation indicates that the introduction of Ga single atoms into the lattice of CdSe QDs enables the efficient separation of photogenerated electron-hole pairs and the enhanced adsorption ability toward CO2 molecule, meanwhile the surface Ga catalytic sites can effectively trap electrons to activate CO2 and suppress H2 evolution.

Keywords: Photocatalytic CO2 reduction, Quantum dots, Selectivity, Single atom catalytic sites, Gallium