Mesoporous hollow hematite Fe₂O₃ fibers were successfully synthesized through centrifugal spinning and applied in photocatalytic H₂ production and CO₂ reduction. Fabrication of hollow hematite fibers includes two innovative synthetic steps, i) centrifugal spinning of precursor fibers using polyvinylpyrrolidone (PVP) as a polymeric part and two different Fe precursors (iron nitrate and iron chloride), ii) annealing of these fibers with different temperatures profiles (250 °C and 600 °C) with optimized heating rates and durations. The prepared samples (FN250, FN600, FC250, and FC600) were thoroughly characterized using SEM, XRD, XPS, and Raman spectroscopy, and the obtained results were correlated with the photocatalytic performance during H₂ production and CO₂ reduction. The FC250 and FC600 samples, which showed a higher concentration of oxygen defects, exhibited superior photocatalytic efficiency compared to the Fe₂O₃ standard. The enhanced performance is attributed to the increased light absorption, improved charge separation, and surface reactivity due to oxygen-related defects. These results highlight the potential of non-stoichiometric Fe₂O₃ nanofibers for environmental remediation and energy conversion applications.

中文翻译：

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离心纺制赤铁矿 Fe2O3 中空纤维：用于 H2 生成和 CO2 还原的高效光催化剂


通过离心纺丝成功合成介孔空心赤铁矿 Fe₂O₃ 纤维，并应用于光催化 H₂ 生产和 CO₂ 还原。空心赤铁矿纤维的制造包括两个创新的合成步骤，i） 使用聚乙烯吡咯烷酮 （PVP） 作为聚合物部分和两种不同的铁前驱体（硝酸铁和氯化铁）对前驱体纤维进行离心纺丝，ii） 在不同的温度曲线（250 °C 和 600 °C）下对这些纤维进行退火，并优化加热速率和持续时间。使用 SEM、XRD、XPS 和拉曼光谱对制备的样品 （FN250、FN600、FC250 和 FC600） 进行了全面表征，所得结果与 H₂ 产生和 CO₂ 还原过程中的光催化性能相关。FC250 和 FC600 样品显示出更高浓度的氧缺陷，与 Fe₂O₃ 标准品相比，表现出优异的光催化效率。性能的增强归因于光吸收的增加、电荷分离的改善以及由于氧相关缺陷引起的表面反应性。这些结果突出了非化学计量 Fe₂O₃ 纳米纤维在环境修复和能源转换应用中的潜力。