In this work, ZnFe₂O₄ spinels doped with different Ce contents were synthesized through a sol–gel method and their morphologies, structures, optical and electronic properties, adsorption capacity for CO₂ and activities for CO₂ photoreduction with H₂O vapor were investigated. The results show that the presence of Ce³⁺ in the ZnFe₂O₄ lattice and CeO₂ particles on the surface of ZnFe₂O₄ can enhance photoabsorption in the visible light region, and promote the effective separation of photogenerated electron–hole pairs. CO₂-TPD and in situ FTIR spectroscopy confirmed that monodentate carbonate (m-CO₃²⁻), bidentate carbonate (b-CO₃²⁻) and bidentate bicarbonate (b-HCO₃⁻) were the main surface species for the coadsorption of CO₂ and H₂O on photocatalyst surfaces. The addition of Ce strengthens the chemical interaction between CO₂ and photocatalyst surfaces and obviously increases the adsorption amount of b-HCO₃⁻ and b-CO₃²⁻ species. As a result, all Ce-doped samples exhibit much higher production rates of H₂, CO and CH₄ when compared to undoped ZnFe₂O₄, and ZFC0.2 has the highest photocatalytic activity among all samples, for which H₂, CO and CH₄ production rates of 19.9, 1.7 and 9.9 μmol g_cat⁻¹ h⁻¹ were achieved, about 4.6, 4.3 and 4.2 times that of undoped ZnFe₂O₄, respectively.

中文翻译：

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掺Ce的ZnFe ₂ O ₄在可见光下用H ₂ O蒸气光催化还原CO ₂。

在这项工作中，通过溶胶-凝胶法合成了掺杂不同铈含量的ZnFe ₂ O ₄尖晶石，其形貌，结构，光学和电子性质，对CO _2的吸附能力以及H ₂ O蒸气对CO _2的光还原活性为：调查。结果表明，Ce的存在³⁺在的ZnFe ₂ Ò ₄晶格和的CeO _2个颗粒的ZnFe的表面上₂ ø ₄可以提高在可见光区域的光吸收，促进光生电子-空穴对的有效分离。CO ₂ -TPD和原位FTIR光谱证实了单齿碳酸酯（M-CO ₃ ^2- ），二齿碳酸酯（B-CO ₃ ^2-）和双齿碳酸氢盐（B-HCO ₃ ^{- ）}是用于CO的共吸附的主表面物种₂和H ₂ O于光催化剂表面。在添加Ce的加强CO之间的化学相互作用₂和光催化剂的表面和明显增加B-HCO的吸附量₃ ^-和b-CO ₃ ^2-物种。结果，所有掺Ce的样品都具有更高的H ₂，CO和CH ₄生产率。当与未掺杂的ZnFe ₂ O ₄相比时，ZFC0.2具有最高的光催化活性，在所有样品中，H ₂，CO和CH _4的生产率分别为19.9、1.7和9.9μmolg _cat ^-1 h ^-1，分别约为未掺杂ZnFe ₂ O _4的4.6、4.3和4.2倍。