Strain-assisted in-situ formed oxygen defective WO3 film for photothermal-synergistic reverse water gas shift reaction and single-particle study

Among the reactions about CO2 conversion, the reverse water gas shift (RWGS) reaction is an efficient method to convert CO2 to CO. Herein, by the assistance of strain and introduction of light and reactant, in-situ formed oxygen defective WO3 film was synthesized, as an effective catalyst for reverse water gas shift reaction with an intense photothermal-synergistic effect. Furthermore, the in-situ single-particle Time-Resolved Photoluminescence (TRPL) and Photoluminescence (PL) spectrum were used to explore the details during the reaction, and prolonged charge carrier lifetime and significantly enhanced Photoluminescence intensities were observed in the in-situ single-particle study. Notably, the production rate of CO for WO3 film is almost 10 times that of powder, which means that WO3 film has an intense photothermal-synergistic effect. As proved by the results of CO2 temperature-programmed desorption (TPD) and CO2 adsorption, the oxygen vacancies are beneficial to the capture and activation of CO2, boosting the process of the reverse water gas shift. Meanwhile, lattice strain arising from the thermal expansion during the reaction could assist the in-situ formation of oxygen defects, enhance charge separation and regulate the electrical structure. All of this contribute to the synergy effect in photothermal reaction. Our work may provide a novel strategy for reasonable design of catalyst and illuminate the behavior of carriers in single-particle level.