The photocatalytic water-mediated CO₂ reduction reaction, which holds great promise for the conversion of CO₂ into valuable chemicals, is often hindered by inefficient separation of photogenerated charges and a lack of suitable catalytic sites. Herein, we have developed a glycerol coordination assembly approach to precisely control the distribution of atomically dispersed Cu species by occupying Ti-defects and adjusting the ratio between Cu species and Ti-defects in a hierarchical TiO₂. The optimal sample demonstrates a ∼4-fold improvement in CO₂-to-CO conversion compared to normal TiO₂ nanoparticles. The high activity could be attributed to the Ti defects, which enhance the photogenerated charge separation and simultaneously facilitate the adsorption of water molecules, thereby promoting the water oxidation reaction. Moreover, by means of in situ EPR and FTIR spectra, we have demonstrated that Cu species can effectively capture photogenerated electrons and facilitate the adsorption of CO₂, so as to catalyze the reduction of CO₂. This work provides a strategy for the construction of atomic-level synergistic catalytic sites and the utilization of in situ techniques to reveal the underlying mechanism.

中文翻译：

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原子分散的 Cu 物种和 Ti 缺陷的协同效应促进分级 TiO2 光催化 CO2 还原

光催化水介导的CO _{2还原反应对于将CO 2}转化为有价值的化学品具有广阔的前景，但常常因光生电荷分离效率低和缺乏合适的催化位点而受到阻碍。在此，我们开发了一种甘油配位组装方法，通过占据Ti缺陷并调整分级TiO ₂中Cu物种和Ti缺陷之间的比例来精确控制原子分散的Cu物种的分布。与普通 TiO _{2纳米颗粒相比，最佳样品的 CO 2}至 CO 转化率提高了约 4 倍。高活性可归因于Ti缺陷，它增强了光生电荷分离，同时促进了水分子的吸附，从而促进了水氧化反应。此外，通过原位EPR和FTIR光谱，我们证明Cu物种可以有效捕获光生电子并促进CO ₂的吸附，从而催化CO ₂的还原。这项工作为构建原子级协同催化位点和利用原位技术揭示潜在机制提供了策略。