Role of oxygen vacancies in Co/Ni Substituted CeO2: A comparative study. Issue 3 (15th February 2019)

• Record Type: Journal Article
• Authors: Tiwari, Saurabh; Khatun, Nasima; Patra, N.; Yadav, A.K.; Bhattacharya, Dibyendu; Jha, S.N.; Tseng, C.M.; Liu, S.W.; Biring, Sajal; Sen, Somaditya
• Is Part Of: Ceramics international. Volume 45:Issue 3(2019)
• Page Start: 3823
• Page End: 3832
• Publication Date: 2019-02-15
• Subjects: Cerium oxide -- Strain -- Bandgap -- Urbach energy, Oxygen vacancies; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2018.11.053
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: Single phase Co/Ni substituted CeO2 nanoparticles reveal the importance of oxygen vacancies on the electronic properties of the materials. The effect of Co/Ni substitution on the structural, optical, and photoluminescence properties of CeO2 have been studied systematically. Lattice shrinks and hence strain increase owing to incorporation of Co/Ni in CeO2 . Optical absorption analysis shows a red shift in band-gap with Co/Ni substitution. Photoluminescence studies reveals increase in defect concentration which causes quenching of PL emission. Vibration modes at ~460 cm −1 in Raman spectra indicates incorporation of Co/Ni in CeO2 lattice whereas a broad peak appearing at ~ 540–640 cm −1 with substitution depicts the defects related to the increase in oxygen vacancy. X-ray absorption (XAS) studies show that Co/Ni substitution maintains local structure while Ce 4+ → Ce 3+ concentration increases to preserve the charge neutrality in lattice.