Photocatalytic CO2 conversion into valuable solar fuels is highly appealing, but lack of directional charge-transfer channel and insufficient active sites resulted in limited CO2 reduction efficiency and selectivity for most photocatalytic systems. Herein, we designed and fabricated rare-earth La single-atoms on carbon nitride with La–N charge-transfer bridge as the active center for photocatalytic CO2 reaction. The formation of La single-atoms was certified by spherical aberration-corrected HAADF-STEM, STEM-EELS, EXAFS, and theoretical calculations. The electronic structure of the La–N bridge enables a high CO-yielding rate of 92 μmol·g–1·h–1 and CO selectivity of 80.3%, which is superior to most g-C3N4-based photocatalytic CO2 reductions. The CO production rate remained nearly constant under light irradiation for five cycles of 20 h, indicating its stability. The closely combined experimental and DFT calculations clearly elucidated that the variety of electronic states induced by 4f and 5d orbitals of the La single atom and the p–d orbital hybridization of La–N atoms enabled the formation of charge-transfer channel. The La–N charge bridges are found to function as the key active center for CO2 activation, rapid COOH* formation, and CO desorption. The present work would provide a mechanistic understanding into the utilization of rare-earth single-atoms in photocatalysis for solar energy conversion.

Sluggish charge kinetics and low CO 2 affinity seriously limit the photocatalytic CO 2 reduction reaction. Herein, the simultaneous promotion of charge transfer and CO 2 activation over two-dimensional (2D) WO 3 nanosheets is achieved by coupling surface C-doping and oxygen vacancy. The surface-doped C atoms reconstruct the atomic surface of WO 3 by extracting oxygen lattice to generate the intimate oxygen vacancy (C−OV coordination) as the active center, which facilitates the CO 2 adsorption/activation, thus inducing the formation *CO 2 species. As a charge delivery channel, an exclusive W−O−C covalent bond formed by C−OV coordination could enhance the electron transfer. As a result, the as-designed catalyst exhibits 85.8% selectivity for CO 2 photoreduction to CO under the gas−solid phase reaction, with a yield rate of 23.2 μmol g −1 h −1 and a stable long-term reactivity over 24 h. Moreover, the in situ DRIFTS and DFT results reveal that this specific C−OV coordination enables the spontaneous CO 2 activation and proton-coupled electron transfer to guarantee the sustained formation of *COOH and, thus, smooth the photocatalytic CO 2 reduction reaction. This work develops a feasible strategy for electronic structure modification of photocatalysts with doping-induced oxygen vacancy to boost CO 2 activation and photoreduction.

Various technologies have been developed towards the air pollution control to mitigate adverse impact of pollutants on human health and ecological environment. Photocatalysis is a promising technology because it can...

The mechanisms of enhanced photocatalysis efficiency and suppression of toxic intermediate production during photocatalytic NO oxidation on B-doped g-C3N4 were revealed.