Photocatalytic CO2reduction by highly dispersed Cu sites on TiO2

Two nanocomposite photocatalysts were synthesized by forming highly dispersed Cu sites on TiO2 surfaces. The synthesized materials were characterized with microscopy, UV-visible, and infrared spectroscopy, and tested in photocatalytic CO2 reduction. Computational modeling was conducted to elucidate the role of single Cu sites in promoting CO2 reduction on TiO2. The nanocomposites demonstrated significantly higher activity than bare TiO2 in photocatalysis, and the activity was found to be related to the chemical state of surface Cu+ species. According to our modeling studies, the highly dispersed Cu sites likely contributed to the improved photocatalysis by stabilizing surface adsorption of CO2 on TiO2. Our experimental and modeling studies further confirmed the direct involvement of surface Cu sites in CO generation via CO2 reduction.