Solar‐driven photothermal CO 2 methanation represents a promising strategy for carbon emission reduction. In this study, a series of LaB 0.6 B′ 0.4 O (3‐ σ ) perovskite catalysts were synthesized via a citrate sol–gel method, and the influence of calcination temperature on their structure and catalytic performance was systematically studied. Characterization techniques, including XRD, BET, XPS, UV–Vis, and TAS, demonstrated that calcination temperature effectively modulates the crystallite size, specific surface area, and defect distribution of the catalysts, thus affecting their charge carrier dynamics and catalytic behavior. All catalysts showed optimal CO 2 methanation performance when calcined at 600°C, among which the LCM catalyst achieved the highest CH 4 yield of 5729.77 μmol·g −1 . Further analysis revealed that a suitable calcination temperature promotes the formation of abundant surface defects, which enhance the adsorption and activation of CO 2 and H 2 O and improve the separation efficiency of photogenerated charge carriers. In contrast, excessively high calcination temperatures introduce deep‐level traps that impede charge carrier migration and lower catalytic activity. This study highlights the essential role of calcination temperature in regulating the properties of perovskite catalysts and offers theoretical insights for the design of efficient photothermal CO 2 conversion materials.
Chen et al. (Sun,) studied this question.