Abstract

Developing an efficient photocatalyst to reduce CO₂ to methanol is still a major challenge. In this paper, the Fe³⁺-doped TiO₂ aerogels were prepared by sol–gel process. Implantation of Fe³⁺ into TiO₂ lattice can not only narrow the band gap of electron transfer, but also suppress the recombination of photogenerated electron–hole pairs. However, when the doping content of Fe³⁺ was increased to 5 mol %, partial Fe³⁺ ions may enter into the lattice gap and decrease the stability of the excited electrons. The UV–Vis diffuse reflectance spectra, photoluminescence (PL) spectra, and UV-excited photoelectron spectroscopy (UPS) were used to study the effect of the Fe³⁺ doping amount on the photoelectric properties of the aerogels. The photocatalytic conversion of CO₂ to methanol was used to evaluate their catalytic performances upon illumination by a 300 W Xe lamp.

The corresponding band alignments indicated that the Fe³⁺-doped TiO₂ aerogels may photocatalytically reduce CO₂ to methanol.

中文翻译：

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Fe 3+掺杂的TiO 2气凝胶的制备及其光催化还原CO 2转化为甲醇的能力

摘要

开发有效的光催化剂以将CO ₂还原为甲醇仍然是主要挑战。本文采用溶胶-凝胶法制备了Fe ³⁺掺杂的TiO ₂气凝胶。将Fe ³⁺注入TiO ₂晶格中不仅可以缩小电子转移的带隙，而且可以抑制光生电子-空穴对的复合。然而，当Fe ³⁺的掺杂含量增加到5 mol％时，部分Fe ³⁺离子可能会进入晶格间隙并降低激发电子的稳定性。UV-Vis漫反射光谱，光致发光（PL）光谱和UV激发光电子能谱（UPS）用于研究Fe ³⁺掺杂量对气凝胶光电性能的影响。CO ₂转化为甲醇的光催化转化用于评估其在300 W Xe灯照明下的催化性能。

相应的能带取向表明，Fe ³⁺掺杂的TiO ₂气凝胶可以将CO ₂光催化还原为甲醇。