Abstract Highly efficient photocatalytic reduction of CO2 is essential for solving the greenhouse effect and energy crisis. In this paper, the Sm-TiO2 nanocomposites were successfully prepared via sol-gel method. The CO2 photoreduction activities of synthesized samples were tested under irradiation for 6 h and the results indicate that the 0.5% Sm-TiO2 catalyst has superior performance and stability. The CO and CH4 yields of 0.5% Sm-TiO2 catalyst are 55.47 and 3.82 μmol/g·cat respectively, which are 5.02 and 2.67 times the yield of TiO2. The possible mechanism of Sm doped TiO2 was investigated through comprehensive characterization and photoelectrochemical analysis. After the Sm doping, the photo-generated electrons in TiO2 could migrate to Sm 4f, and some of them can be captured by reducing Sm3+ to Sm2+, which can lower the recombination rate of electron and hole pairs. Therefore, the enhanced photocatalytic performance could be ascribed to large specific surface area, fast separation rate of electron–hole pairs and high visible light response. This report provides some meaningful attempts in researching the CO2 photocatalytic reduction.

中文翻译：

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在 Sm 掺杂的 TiO2 纳米颗粒上光催化还原 CO2

摘要 高效光催化还原二氧化碳对于解决温室效应和能源危机至关重要。本文采用溶胶-凝胶法成功制备了Sm-TiO2纳米复合材料。合成样品的 CO2 光还原活性在辐照 6 h 下进行测试，结果表明 0.5% Sm-TiO2 催化剂具有优异的性能和稳定性。0.5% Sm-TiO2催化剂的CO和CH4产率分别为55.47和3.82 μmol/g·cat，分别是TiO2产率的5.02和2.67倍。通过综合表征和光电化学分析研究了 Sm 掺杂 TiO2 的可能机制。Sm掺杂后，TiO2中的光生电子可以迁移到Sm 4f，其中一些可以通过将Sm3+还原为Sm2+而被捕获，可以降低电子和空穴对的复合率。因此，增强的光催化性能可归因于大的比表面积、快速的电子-空穴对分离速度和高的可见光响应。本报告为研究 CO2 光催化还原提供了一些有意义的尝试。