Oxygen Vacancy and Metallic Silver Site Coinjection Associates Photocatalytic CO<sub>2</sub> Reduction upon Mesoporous NH<sub>2</sub>–TiO<sub>2</sub> Nanoparticles Assembly
Jinyan Xiong, Xueteng Zhu, Zhangjing Chen, Yinan Ren, Weiming Wang, Chao Han, Weijie Li, Shaozhong Li, Gang Cheng
Abstract
Solar‐driven CO 2 conversion is a promising approach to tackle the issues of increasing greenhouse gases and energy shortage. Herein, a defective amine/silver species‐modified mesoporous TiO 2 (NH 2 –TiO 2− x –Ag) nanoparticle assembly for photocatalytic CO 2 reduction is reported. In particular, simultaneous oxygen vacancy incorporation and silver species anchoring in the formation of NH 2 –TiO 2 derived from amine‐modified protonated titanate during polyol‐mediated solvothermal treatment are achieved. Indeed, the NH 2 –TiO 2− x –Ag with different amounts of Ag species can enhance photocatalytic CO 2 reduction into CH 4 and CO. The NH 2 –TiO 2− x –Ag‐0.05 sample has the highest CH 4 and CO yields with rates of 6.11 and 0.91 μmol g −1 h −1 , respectively, which are about 10.7 and 7 times higher than that of pristine NH 2 –TiO 2 . These findings demonstrate that the synergic impact of oxygen vacancies and metallic silver sites embedded into NH 2 –TiO 2 can prevent poor light harvesting, fast recombination of photogenerated electrons and holes, and inadequate surface‐active sites.