The surface electron density significantly affects the photocatalytic efficiency, especially the photocatalytic CO2 reduction reaction, which involves multi-electron participation in the conversion process. Herein, we propose a conceptually different mechanism for surface electron density modulation based on the model of Au anchored CdS. We firstly manipulate the direction of electron transfer by regulating the vacancy types of CdS. When electrons accumulate on vacancies instead of single Au atoms, the adsorption types of CO2 change from physical adsorption to chemical adsorption. More importantly, the surface electron density is manipulated by controlling the size of Au nanostructures. When Au nanoclusters downsize to single Au atoms, the strong hybridization of Au 5d and S 2p orbits accelerates the photo-electrons transfer onto the surface, resulting in more electrons available for CO2 reduction. As a result, the product generation rate of AuSA/Cd1−xS manifests a remarkable at least 113-fold enhancement compared with pristine Cd1−xS.

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Limited by the chemical inertness of CO 2 and the high dissociation energy of the CO bond, photocatalytic CO 2 conversion is highly challenging. Herein, we prepare ultrathin oxygen-modified h-BN (O/BN) nanosheets containing B−O bonds. On the O/BN surface, CO 2 can be chemically captured and is bonded with the B−O bond, leading to the formation of an O−B−O bond. This new chemical bond acting as an electron-delivery channel strengthens the interaction between CO 2 and the surface. Thus, the reactants can continuously obtain electrons from the surface through this channel. Therefore, the majority of gaseous CO 2 directly converts into carbon active species that are detected by in situ DRIFTS over O/BN. Moreover, the activated energies of CO 2 conversion are significantly reduced with the introduction of the B−O bond evidenced by DFT calculations. As a result, O/BN nanosheets present an enhanced photocatalytic CO 2 conversion performance with the H 2 and CO generation rates of 3.3 and 12.5 μmol g −1 h −1 , respectively. This work could help in realizing the effects of nonmetal chemical bonds in the CO 2 photoreduction reaction for designing efficient photocatalysts.

Photothermal catalysis, which couples both solar and thermal energies, has burgeoned as a promising approach to drive catalytic reactions. However, the utilization of light irradiation to tune the reaction paths to obtain ideal product distribution in photothermal catalysis is still of tremendous challenge. Herein, we successfully regulated the relationship between two core competition reactions through light irradiation during photothermal dry reforming of methane over Ni/Ga2O3, resulting in the promotion of H2 formation and the suppression of the reverse water gas shift reaction. The increase in the H2/CO ratio from 0.55 to 0.94 could be achieved. Furthermore, the combination of density functional calculations and X-ray photoelectron spectroscopy reveals that light irradiation impelled the direction of electron transfer to be reversed from Ga2O3 to Ni to form the Ni0 sites, which provides the generation of abundant hot electrons from the electronic interband transition of Ni to boost the formation and desorption of H2. This work promotes the understanding of nonthermal behaviors of light irradiation in light-driven photochemistry, which is significant for designing catalysts with high efficiency and controllable product distribution.