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.

BiOCl has been used in the photoreduction of CO2, but exhibits limited photocatalytic activity. In this study, Bi was in situ reduced and deposited on the surface of (001)-dominated BiOCl nanosheets by NaBH4 to form Bi/BiOCl nanosheets enriched with oxygen vacancies. The as-prepared Bi/BiOCl nanosheets having low thickness (ca. 10 nm) showed much higher concentration of oxygen vacancies compared to Bi/BiOCl nanoplates having high thickness (ca. 100 nm). Subsequently, the photocatalytic activity of the Bi/BiOCl nanosheets enriched with oxygen vacancies for CO2 reduction was dramatically enhanced and much higher than that of BiOCl nanoplates, nanosheets, and Bi/BiOCl nanoplates. It showed that the improved photocatalytic activity in the reduction of CO2 can be attributed to the enhanced separation efficiency of photogenerated electron–hole pairs of the oxygen vacancies on BiOCl nanosheets and Bi metals. This work demonstrated that the in situ reduction of non-noble metals on the surface of BiOCl nanosheets that are enriched with oxygen vacancies is favorable for increasing photocatalytic CO2 reduction.

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