Hollow-structured TiO₂ is promising for photocatalytic CO₂ reduction due to its high surface area and light absorption. This study aims to enhance its photocatalytic activity through the engineering of Cu and CuAg alloy cocatalysts. Hollow TiO₂ was synthesized by a hard template method, followed by Cu loading and CuAg alloy formation via a chemical replacement reaction. The optimal 7% Cu loading achieved the highest CH₄ yield of 2.47 μmol g^-1 h^-1 among the TiO₂-Cu composites. Introducing Ag further enhanced the performance, with the Cu:Ag= 9:1 alloy boosting the CH₄ yield to 6.72 μmol g^-1 h^-1, approximately 14 times that of pure TiO₂. Characterization techniques such as XRD, SEM, and XPS were also employed to analyze the phase composition, microstructure, and photoelectrochemical properties of the synthesized materials. The experimental findings indicate that the introduction of the CuAg alloy significantly promotes charge separation and transfer efficiency, and increases the effective active sites on the TiO₂ surface, thereby greatly enhancing the efficiency of the photocatalytic reaction. These findings offer insights into the design of efficient photocatalytic materials for sustainable energy applications.

中文翻译：

---

助催化剂工程促进光催化还原空心 TiO2 纳米球：从 Cu 纳米颗粒到 CuAg 物种


空心结构的 TiO₂ 由于其高表面积和光吸收性，有望通过光催化还原 CO₂。本研究旨在通过 Cu 和 CuAg 合金助催化剂的工程来提高其光催化活性。采用硬质模板法合成空心 TiO₂，然后通过化学置换反应制备 Cu 负载和 CuAg 合金。在 TiO_2-Cu 复合材料中，最佳的 7% Cu 负载实现了最高的 CH₄ 产率，为 2.47 μmol ^{g-1 h-1}。引入 Ag 进一步增强了性能，Cu：Ag= 9：1 合金将 CH₄ 的产率提高到 6.72 μmol ^{g-1 h-1}，大约是纯 TiO₂ 的 14 倍。还采用了 XRD 、 SEM 和 XPS 等表征技术来分析合成材料的物相组成、微观结构和光电化学性质。实验结果表明，CuAg 合金的引入显著提高了电荷分离和转移效率，并增加了 TiO₂ 表面的有效活性位点，从而大大提高了光催化反应的效率。这些发现为可持续能源应用设计高效的光催化材料提供了见解。