Cu is a key element for many photo- and electro-driven catalyst systems, but it readily undergoes natural oxidation in air and electron-mediated support interactions when in contact with reducible oxides. The production of value-added hydrocarbons via photocatalytic CO₂ reduction is promising, but it remains an unresolved challenge due to the hurdles associated with controlling the valence state of the Cu cocatalyst within a heterogeneous composite formed as a result of oxidative stabilization during nucleation process. Herein, we report a local-charge-mediated strategy to synthesize Cu nanoparticles on a TiO₂ photocatalyst, thus inducing a stable intermediate Cu valence state favorable for spontaneous C–C dimerization. Distinctive to fast-driven Cu²⁺-dominant valence state generation upon photoreduction, the negatively charged local electrons within the oxygen-deficient TiO_2–x environment facilitates anoxic stabilization toward the Cu⁺-dominant valence state under dark conditions. Supported by combined structural analysis and theoretical calculations, the optimized Cu/TiO_2–x exhibited a significant photocatalytic ethylene production rate of 1.85 μmol/g·h, making this a potential strategy to utilize interfacial coordination chemistry.

中文翻译：

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TiO2 上电荷介导的稳定低价 Cu 用于光催化 CO2 生产乙烯

Cu 是许多光驱动和电驱动催化剂系统的关键元素，但当与可还原氧化物接触时，它很容易在空气中发生自然氧化和电子介导的载体相互作用。通过光催化CO ₂还原生产增值碳氢化合物是有前景的，但由于在成核过程中氧化稳定形成的异质复合材料中控制Cu助催化剂的价态存在障碍，这仍然是一个未解决的挑战。在此，我们报告了一种局部电荷介导的策略，在 TiO ₂光催化剂上合成 Cu 纳米粒子，从而诱导有利于自发 C-C 二聚的稳定的中间 Cu 价态。与光还原时快速驱动的 Cu ²⁺主导价态生成不同，缺氧 TiO _{2– x}环境中带负电的局部电子有助于在黑暗条件下缺氧稳定到 Cu ⁺主导价态。在结构分析和理论计算相结合的支持下，优化后的Cu/TiO _{2– x}表现出1.85 μmol/g·h的显着光催化乙烯生产率，使其成为利用界面配位化学的潜在策略。