Kumar Raj, Gupta Vipin Kumar, Khosya Mohit, Singh Sangeeta, Kumar Upendra
Advanced Functional Materials Laboratory, Department of Applied Sciences, Indian Institute of Information Technology Allahabad, Jhalwa, Prayagraj, 211015, India.
Department of Physics, Indian Institute of Technology Delhi, Hauz Khas, New Delhi, 110016, India.
Sci Rep. 2025 Jun 2;15(1):19269. doi: 10.1038/s41598-025-04843-2.
A comprehensive comparative study was conducted on synthesized (CS) and commercially procured (CP) cerium oxide (CeO₂) samples, and evaluating their computational, structural, microstructural, biocompatibility, and electrical properties. First-principles computational studies revealed that CS exhibited greater volume optimization than CP, although both samples demonstrated a band gap of 2.4–2.5 eV, consistent with the semiconducting nature of CeO₂. The density of states analysis indicated a strong hybridization between Ce-4f and O-2p orbitals, with CS, displaying enhanced electronic density near the Fermi level. X-ray diffraction studies followed by Rietveld refinement confirmed the fluorite structure. Microstructural analysis showed dense, agglomerated morphologies in both samples. However, CS exhibited a higher oxygen content than CP, implying variation in defect concentrations. FTIR confirmed phase purity with characteristic Ce–O vibrations at 435 and 1631 cm¹, while Raman spectroscopy supported this by revealing the F₂g mode (~ 465 cm¹) typical of fluorite-structured CeO₂. Electrical impedance spectroscopy revealed higher ionic conductivity in CS, with a lower grain boundary blocking factor (αgb = 0.42) compared to CP (αgb = 0.62), likely due to differences in defect density and microstructure. Biocompatibility tests showed that CeO₂-300 (CS) had the highest inhibitory efficacy (IC₅₀ ≈ 65.94 µg/ml), followed by CeO₂-800 (≈ 74.1 µg/ml) and CeO₂-Pure (CP) (≈ 86.88 µg/ml), indicating the influence of synthesis on biological response. These results highlight the critical impact of synthesis methods on the biocompatibility and electrical performance of CeO₂ materials useful as solid electrolyte in IT-SOFCs application.
对合成的（CS）和商业采购的（CP）氧化铈（CeO₂）样品进行了全面的比较研究，并评估了它们的计算、结构、微观结构、生物相容性和电学性质。第一性原理计算研究表明，尽管两个样品的带隙均为2.4 - 2.5 eV，与CeO₂的半导体性质一致，但CS表现出比CP更大的体积优化。态密度分析表明Ce-4f和O-2p轨道之间有强烈的杂化，CS在费米能级附近显示出增强的电子密度。X射线衍射研究及随后的Rietveld精修证实了萤石结构。微观结构分析表明两个样品均呈现致密、团聚的形态。然而，CS的氧含量高于CP，这意味着缺陷浓度存在差异。傅里叶变换红外光谱（FTIR）通过在435和1631 cm⁻¹处的特征Ce - O振动证实了相纯度，而拉曼光谱通过揭示萤石结构CeO₂典型的F₂g模式（~ 465 cm⁻¹）支持了这一点。电阻抗谱显示CS具有更高的离子电导率，与CP（αgb = 0.62）相比，其晶界阻挡因子较低（αgb = 0.42），这可能是由于缺陷密度和微观结构的差异所致。生物相容性测试表明，CeO₂ - 300（CS）具有最高的抑制效果（IC₅₀≈65.94 μg/ml），其次是CeO₂ - 800（≈74.1 μg/ml）和CeO₂ - Pure（CP）（≈86.88 μg/ml），这表明合成对生物反应有影响。这些结果突出了合成方法对用作IT - SOFCs应用中固体电解质的CeO₂材料的生物相容性和电学性能的关键影响。
