Molecular Terpyridine-Lanthanide Complexes Modified Carbon Nitride for Enhanced Photocatalytic CO2 Reduction.

Molecule/semiconductor hybrid catalysts, which combine molecular metal complexes with semiconductors, have shown outstanding performances in photocatalytic CO2 reduction. In this work, we report two hybrid catalysts for the selective photoreduction of CO2 to CO. One is composed of carbon nitride and a terpyridine-Lu complex (denoted as LutpyCN), and the other is composed of carbon nitride and a terpyridine-Ce complex (denoted as CetpyCN). Compared with pristine carbon nitride, the hybrid catalysts LutpyCN and CetpyCN display a noteworthy increase in CO generation, boosting the yield by approximately 176 times and 106 times, respectively. Mechanistic studies demonstrate that such significant enhancement in photocatalysis is primarily due to more efficient separation of photogenerated carriers for hybrid catalysts after modifying CN with molecular terpyridine-lanthanide species.

A Small Organic Molecular Catalyst with Efficient Electron Accumulation for Near-unity CO2 Photoreduction.

Molecular catalysis is of great interest to CO2 photoreduction. Various transition metal complexes have been developed as efficient molecular catalysts. However, it remains a challenge to catalyze CO2 reduction by a small organic molecular photocatalyst, as the accumulation of multiple electrons in a small organic molecule is normally difficult for CO2 reduction. We report herein a small organic molecular catalyst can be used for selective reduction of CO2 to CO under visible light irradiation. The turnover number (TON) of CO formation is found to be 400±26 with near 100% selectivity in DMF/H2 O medium. UV-Vis absorption spectroscopy, density functional theory (DFT) calculations, and spectroelectrochemical studies demonstrate that the organic molecular catalyst is capable of accumulating electrons through a 2e- reduced product which shows good stability and is responsible for interacting with CO2 . These findings elucidate an accessible way to develop purely organic molecular catalysts for CO2 reduction by strengthening the electron accumulation.

Exploiting consecutive photoinduced electron transfer (ConPET) in CO2 photoreduction.

The consecutive photoinduced electron transfer (ConPET) process of 1,2,3,5-Tetrakis(carbazol-9-yl)-4,6-dicyanobenzene (4CzIPN) in CO2 photoreduction to achieve powerful reducing species has been disclosed by activating a bis(terpyridine)ruthenium(II) complex bearing a high overpotential for selective light-driven reduction of CO2 to CO in homogeneous solution.