Evaluation on La2O3 garlanded ceria heterostructured binary metal oxide nanoplates for UV/ visible light induced removal of organic dye from urban wastewater

• Published in: South African journal of chemical engineering 2018-12, Vol.26 (1), p.49-60
• Main Authors: Maria Magdalane, C., Kaviyarasu, K., Matinise, N., Mayedwa, N., Mongwaketsi, N., Letsholathebe, Douglas, Mola, G.T., AbdullahAl-Dhabi, Naif, Arasu, Mariadhas Valan, Henini, M., Kennedy, J., Maaza, M., Jeyaraj, B.
• Format: Article
• Language: English
• Subjects: CeO2:La2O3; Electron microscopy; Heterogeneous catalysts; Photocatalytic activity; RhB dye
• ISSN: 1026-9185
• DOI: 10.1016/j.sajce.2018.09.003

A low energy bandgap between Ce3+ and Ce4+ states in cerium oxides, high oxygen mobility and high oxygen storage capacity are the properties that qualify them to be the most widely used heterogeneous catalysts. This present work is an account of studies that were carried out on the synthesis and catalytic properties of pure CeO2, CeO2/La2O3 based binary metal oxide nanostructures prepared by the hydrothermal method. Our results revealed that the synthesis temperature and pressure during hydrothermal reactions played a critical role in controlling the shape, size, oxygen vacancy, and low temperature reducibility in CeO2 based nanostructures. In addition, OH− ion concentration was found to play an important role in engineering the lattice constants and oxygen vacancy defects. The present report demonstrated that the hydrothermal synthesis is a facile one step approach for the preparation of compositionally homogeneous cerium based binary metal oxide nanostructures, in which CeO2/La2O3 mixed oxides have a superior low-temperature oxygen release capability compared to pure CeO2. We have also demonstrated that the nanomaterials are proved to have higher catalytic performance at low temperatures as compared to pure ceria nanoparticles. [Display omitted] •Bandgap between Ce3+ and Ce4+ states in cerium oxides, high oxygen mobility.•Inter conversion of Ce4+ to Ce3+ ratio enhances the photon-induced dye degradation.•Due to the larger cation, La3+ substituting for Ce4+ in the CeO2 lattice.•Ceria rich nanostructures like Ce2/La1 and Ce1/La1 there is no additional diffraction.•Shift in the peak position the difference in ionic size between Ce4+ and La3+.