In recent years, metal–semiconductor heterojunctions have been intensively researched in the field of photocatalysis due to the effective spatial separation of photo-induced electron-hole pairs. Here, the dual-functional copper (Cu⁰/Cu²⁺)-modified SrTiO_3-δ nanosheets (Cu/STCO) are successfully synthesized by a two-step route. First, Cu²⁺-doped SrTiO_3-δ (STCO) nanosheets are synthesized by a hydrothermal method and then Cu⁰ nanoparticles (NPs) are in situ formed from the STCO under H₂ atmosphere at 500 °C. The optimized ratio 6 %-Cu/STCO photocatalyst exhibits the best photothermal catalytic performance for CO₂ reduction reaction (CO₂RR) and H₂ evolution performance. The detailed characterization demonstrate that the Cu²⁺ dopant extend the light absorption range and the in situ generated Cu⁰ NPs effectively improve the separation ability of photogenerated charge carriers by forming the Schottky contact with STCO. The excited localized surface plasmon resonance (LSPR) effect of metallic Cu⁰ in Cu/STCO shows a considerable catalysis performance even under 600 nm monochromatic light irradiation. The density functional theory (DFT) calculations suggest that the Cu/STCO diminishes the barrier of the rate-determining steps of the CO₂RR and H₂ evolution thus perform the outstanding catalysis ability in two filed. This work presents the synergistic effect of Cu⁰ and Cu²⁺ on enhancing the photothermal catalytic performance for CO₂RR and H₂ evolution and offers a novel strategy to synthesize the metal–semiconductor nanostructures for efficient harnessing of solar energy into fuel.

近年来，由于光生电子-空穴对的有效空间分离，金属-半导体异质结在光催化领域得到了深入研究。在这里，双功能铜（Cu ⁰ /Cu ²⁺）修饰的SrTiO _3-δ纳米片（Cu/STCO）通过两步法成功合成。首先，通过水热法合成Cu ²⁺掺杂的SrTiO _3-δ (STCO)纳米片，然后在500℃的H ₂气氛下由STCO原位形成Cu ^{0纳米颗粒(NPs)。}优化后的 6%-Cu/STCO 光催化剂对 CO _{2表现出最佳的光热催化性能}还原反应（CO ₂ RR）和H ₂释放性能。详细表征表明，Cu ²⁺掺杂剂扩展了光吸收范围，并且原位产生的Cu ⁰ NPs通过与STCO形成肖特基接触，有效地提高了光生电荷载流子的分离能力。即使在600 nm单色光照射下，金属Cu ⁰在Cu/STCO中的激发局部表面等离子体共振（LSPR）效应也显示出相当大的催化性能。密度泛函理论 (DFT) 计算表明，Cu/STCO 降低了 CO ₂ RR 和 H _{2的速率决定步骤的势垒}进化因此在两个领域表现出出色的催化能力。这项工作展示了Cu ⁰和Cu ²⁺对提高CO ₂ RR 和H ₂释放的光热催化性能的协同作用，并提供了一种合成金属-半导体纳米结构的新策略，以有效地将太阳能转化为燃料。