Photocatalytic conversion of CO₂ into carbonaceous feedstock chemicals is a promising strategy to mitigate greenhouse gas emissions and simultaneously store solar energy in chemical form. Photocatalysts for this transformation are typically based on precious metals and operate in nonaqueous solvents to suppress competing H₂ generation. In this work, we demonstrate selective visible-light-driven CO₂ reduction in water using a synthetic photocatalyst system that is entirely free of precious metals. We present a series of self-assembled nickel terpyridine complexes as electrocatalysts for the reduction of CO₂ to CO in organic media. Immobilization on CdS quantum dots allows these catalysts to be active in purely aqueous solution and photocatalytically reduce CO₂ with >90% selectivity under UV-filtered simulated solar light irradiation (AM 1.5G, 100 mW cm^–2, λ > 400 nm, pH 6.7, 25 °C). Correlation between catalyst immobilization efficiency and product selectivity shows that anchoring the molecular catalyst on the semiconductor surface is key in controlling the selectivity for CO₂ reduction over H₂ evolution in aqueous solution.

中文翻译：

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通过在CdS纳米晶体上固定分子镍催化剂在水中选择性光催化CO ₂还原

将CO ₂光催化转化为含碳原料化学物质是减少温室气体排放并同时以化学形式储存太阳能的一种有前途的策略。用于该转化的光催化剂通常基于贵金属，并在非水溶剂中运行以抑制竞争的H ₂生成。在这项工作中，我们演示了使用完全不含贵金属的合成光催化剂系统选择性地减少可见光驱动的水中的CO ₂还原。我们提出了一系列自组装的镍吡啶吡啶配合物作为减少CO _2的电催化剂有机介质中转化为一氧化碳。固定在CdS量子点上可使这些催化剂在纯水溶液中具有活性，并在经紫外线过滤的模拟太阳光辐射下（AM 1.5G，100 mW cm ^–2，λ> 400 nm，pH）以> 90％的选择性光催化还原CO ₂ 6.7，25°C）。催化剂固定化效率与产物选择性之间的相关性表明，将分子催化剂锚定在半导体表面上是控制水溶液中H ₂析出时CO ₂还原选择性的关键。