Particle Size-Dependent Charge Transfer Dynamics for Boosting CO<sub>2</sub> Photoreduction over Ag/TiO<sub>2</sub> Heterojunction
Shicheng Liu, Qulan Zhou, Du Wen, Chenyang Wu, Yuqing Pan, Xiong Liu, Zhong Huang, Na Li
Abstract
Photocatalytic CO 2 reduction (PCO 2 R) represents a critical pathway in renewable energy generation. Silver nanoparticles (Ag NPs) of varying sizes were deposited on TiO 2 surfaces, exhibiting size-dependent catalytic activities and selectivities due to distinct charge transfer dynamics. The integration of the particle size and Ag/TiO 2 Schottky junction density supplied ample active sites for CO 2 reduction. Modifying the size of the Ag NPs significantly enhanced the photocatalytic performance of the Ag/TiO 2 heterojunction. Notably, Ag 0.5% /TiO 2 showed a CO generation rate of 86.8 μmol g –1 h –1, which was 1.79 times higher than that of anatase. More importantly, Ag 3.0% /TiO 2 resulted in the highest selectivity of CH 4 (28.1%). The particle size of Ag NPs influenced the ratio of thermal electron transfer during photoexcitation and the intermediate product pathways in the CO 2 reduction process. This research provides insights and experimental foundations for particle size regulation in designing heterojunction catalysts for PCO 2 R.