Inerbaev Talgat M, Karakoti Ajay S, Kuchibhatla Satyanarayana V N T, Kumar Amit, Masunov Artëm E, Seal Sudipta
Gumilyov Eurasian National University, Astana, 010008, Republic of Kazakhstan.
Phys Chem Chem Phys. 2015 Mar 7;17(9):6217-21. doi: 10.1039/c4cp04961f.
Experimental and theoretical investigations were performed to investigate the effect of water on optical properties of nanoceria as a function of Ce(3+) concentration. Theoretical studies based on density functional plane-wave calculations reveal that the indirect optical transitions in bare ceria nanoparticles are red-shifted with an increase in the concentration of Ce(3+). However, ceria nanoparticles model with adsorbed water molecules show a blue shift in the indirect optical spectra under identical conditions. Direct optical transitions are almost independent of Ce(3+) concentration but show a pronounced blue shift in the aqueous environment relative to the bare nanoparticles. The theoretical study is consistent with our experimental observation in difference of shift behaviour in bare and aqueous suspended ceria nanoparticles. This change from red- to blue-shift in indirect optical transitions is associated with the polarization effect of water molecules on f-electron states.
开展了实验和理论研究，以探究水对纳米氧化铈光学性质的影响，该影响是铈（III）浓度的函数。基于密度泛函平面波计算的理论研究表明，裸露的氧化铈纳米颗粒中的间接光学跃迁会随着Ce(3+)浓度的增加而发生红移。然而，吸附了水分子的氧化铈纳米颗粒模型在相同条件下的间接光谱中显示出蓝移。直接光学跃迁几乎与Ce(3+)浓度无关，但相对于裸露的纳米颗粒，在水环境中显示出明显的蓝移。理论研究与我们关于裸露的和水悬浮的氧化铈纳米颗粒位移行为差异的实验观察结果一致。间接光学跃迁中这种从红移到蓝移的变化与水分子对f电子态的极化效应有关。
