通过时间分辨激发和发射光谱法证实纳米氧化铈材料对镧系元素氧化物具有卓越的“溶解”能力。

Exceptional capability of nanosized CeO(2) materials to "dissolve" lanthanide oxides established by time-gated excitation and emission spectroscopy.

作者信息

Tiseanu Carmen, Parvulescu Vasile, Avram Daniel, Cojocaru Bogdan, Sanchez-Dominguez Margarita

机构信息

National Institute for Laser, Plasma and Radiation Physics, P.O. Box MG-36, RO 76900, Bucharest-Magurele, Romania.

出版信息

Dalton Trans. 2014 May 28;43(20):7622-30. doi: 10.1039/c3dt53254b.

DOI:10.1039/c3dt53254b

PMID:24699698

Abstract

The atomic scale homogeneity of Ce and Zr oxygen bonds represents the main reason for enhanced total oxygen storage capability of CeO2-ZrO2 (Ce/Zr = 1) as compared to that of CeO2. Here, we demonstrate that the addition of 10% Eu(3+) by wet impregnation on preformed nanosized CeO2-ZrO2 (Ce/Zr = 1) followed by calcination induces a remarkable homogeneity of 10% Eu(3+)-CeO2-ZrO2 solid solution. By use of time-resolved emission and excitation spectroscopies, the improvement of the nanoscale chemical and structural homogeneity of 10% Eu(3+)-CeO2-ZrO2 calcined at 1000 as compared to sample calcined at 750 °C is demonstrated. Based on the comparison of luminescence properties of 10% Eu(3+) impregnated on preformed nanosized CeO2-ZrO2 and CeO2, we also show that the presence of zirconium does not only preserve the ability of cerium oxide to "dissolve" lanthanide oxide, but also determines an important stabilization of defects (oxygen vacancies) generated upon Eu(3+) doping.

摘要

与CeO₂相比，Ce和Zr氧键在原子尺度上的均匀性是CeO₂-ZrO₂（Ce/Zr = 1）总储氧能力增强的主要原因。在此，我们证明通过湿浸渍法在预制的纳米尺寸CeO₂-ZrO₂（Ce/Zr = 1）上添加10%的Eu(3+)，随后进行煅烧，可诱导形成10% Eu(3+)-CeO₂-ZrO₂固溶体的显著均匀性。通过时间分辨发射光谱和激发光谱，证明了与在750℃煅烧的样品相比，在1000℃煅烧的10% Eu(3+)-CeO₂-ZrO₂纳米尺度化学和结构均匀性得到了改善。基于对负载在预制纳米尺寸CeO₂-ZrO₂和CeO₂上的10% Eu(3+)发光性质的比较，我们还表明锆的存在不仅保留了氧化铈“溶解”镧系氧化物的能力，而且还决定了Eu(3+)掺杂时产生的缺陷（氧空位）的重要稳定性。