Cu₂O, a photoactive p‐type semiconductor based on earth‐abundant elements, shows promising features for photoelectrochemical CO₂ reduction reaction (PEC CO2RR). However, despite the broad light absorption and appropriate conduction band edge energy, it promptly undergoes photocorrosion in PEC CO2RR conditions. Herein, we evaluate an amine‐functionalized polysiloxane (AF−PSi) as both protective layer and PEC CO2RR promoter via amine‐CO₂ adduct formation. Electrochemistry experiments and X‐ray diffraction showed that photostability is significantly enhanced with AF−PSi overlayer. Electrolyses experiments under visible light irradiation indicated selective production of formate with faradaic efficiency of 61 % at low overpotential. Detailed in situ FTIR studies revealed that amine groups bind to CO₂ to form carbamate species and that this process is favoured by cathodic polarization, confirming the dual role of AF−PSi layer.

中文翻译：

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氨基聚硅氧烷作为Cu2O光电覆层：光腐蚀抑制剂和低过高的CO2形成甲酸选择性促进剂

Cu ₂ O是一种基于稀土元素的光敏p型半导体，具有光电化学CO ₂还原反应（PEC CO2RR）的广阔前景。但是，尽管吸收了宽广的光并具有适当的导带边缘能，它在PEC CO2RR条件下仍会迅速发生光腐蚀。在本文中，我们评估了胺官能化的聚硅氧烷（AF-PSi）作为保护层和PEC CO2RR促进剂的作用，是通过胺-CO ₂加合物的形成。电化学实验和X射线衍射表明，AF-PSi覆盖层显着增强了光稳定性。在可见光照射下的电解实验表明，在低过电势下选择性产生甲酸盐，法拉第效率为61％。原位详细FTIR研究表明，胺基团与CO ₂结合形成氨基甲酸酯类，并且该过程受到阴极极化的支持，这证实了AF-PSi层的双重作用。