Photocatalytic CO₂ reduction in presence of H₂O provides an ideal way to alleviate the greenhouse effect and obtain valuable chemicals. Constructing active sites on the surface of photocatalysts significantly affects the activity and selectivity of photocatalytic CO₂ reduction, which involves a multi-electron reduction process. Herein, we anchor Ag and Pd particles on the surface of layered perovskite SrBi₂Ta₂O₉ to build CO and CH₄ evolution sites, respectively, via a photodeposition method. Ag and Pd not only attract and accumulate the photoinduced electrons originating from SrBi₂Ta₂O₉ due to the formed Schottky junction between them, but also activate CO₂ molecules, thereby resulting in higher CO₂ reduction activity. On the surface of Ag, intermediate species CO* desorb and form CO directly, whereas, on the surface of Pd, intermediate species CO* is further hydrogenated to form CH₄, thus resulting in different selectivity. This work offers a new avenue for developing photocatalysts with high activity and selectivity for CO₂ reduction.

_{在H 2} O存在下光催化CO ₂还原提供了减轻温室效应和获得有价值化学品的理想途径。在光催化剂表面构建活性位点显着影响光催化CO ₂还原的活性和选择性，这涉及多电子还原过程。在此，我们通过光沉积方法将 Ag 和 Pd 颗粒锚定在层状钙钛矿 SrBi ₂ Ta ₂ O ₉的表面，分别构建 CO 和 CH _{4演化位点。Ag和Pd不仅吸引和积累源自SrBi 2} Ta ₂的光生电子O ₉由于它们之间形成了肖特基结，而且还激活了CO ₂分子，从而导致更高的CO ₂还原活性。在Ag表面，中间体CO*直接脱附形成CO，而在Pd表面，中间体CO*进一步氢化形成CH ₄，从而导致不同的选择性。_{这项工作为开发具有高活性和选择性的 CO 2}还原光催化剂提供了一条新途径。