CeO2–TiO2 mixed oxide thin films with enhanced photocatalytic degradation of organic pollutants

• Published in: Journal of sol-gel science and technology Vol. 82; no. 3; pp. 772 - 782
• Main Authors: Moongraksathum, Benjawan, Chen, Yu-Wen
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.06.2017; Springer Nature B.V
• Subjects: Absorption spectra; Aqueous solutions; Atomic beam spectroscopy; Atomic force microscopy; Catalytic activity; Ceramics; Cerium oxides; Chemistry and Materials Science; Colloiding; Composites; Glass; Heterojunctions; Inorganic Chemistry; Light irradiation; Materials Science; Methylene blue; Microscopy; Mixed oxides; Nanocrystals; Nanotechnology; Natural Materials; Optical and Electronic Materials; Original Paper: Sol-gel and hybrid materials for catalytic; Photocatalysis; Photodegradation; photoelectrochemical and sensor applications; Photoelectrons; Pollutants; Sol-gel processes; Sols; Spectrum analysis; Thin films; Titanium dioxide; Titanium oxides; Transmission electron microscopy; X-ray diffraction; Coating; Binary oxide; Titania; Ceria; Peroxo sol–gel; Methylene blue
• ISSN: 0928-0707; 1573-4846
• DOI: 10.1007/s10971-017-4355-6

A series of CeO 2 –TiO 2 mixed oxides were prepared by the peroxo sol–gel method. X-ray diffraction, transmission electron microscopy, ultraviolet–visible spectroscopy, atomic force microscopy, and X-ray photoelectron spectroscopy were used to investigate the characteristics of CeO 2 –TiO 2 sols and thin films in order to determine the influence of adding CeO 2 to TiO 2 on the photocatalytic degradation of methylene blue aqueous solution under both ultraviolet and visible light irradiation. The pH values of the as-prepared CeO 2 –TiO 2 sols were neutral; the as-prepared sols contained nanocrystals in colloidal suspensions, and there was no subsequent calcination process. It was observed that the highest photocatalytic degradation activities with respect to methylene blue under both UV and visible light irradiation were exhibited for an optimum CeO 2 –TiO 2 weight ratio of 0.05. The high photocatalytic activity was because of changes in the spectral absorption of material, which was attributed to the heterojunction formed by TiO 2 and CeO 2 networks via Ti–O–Ce bonds after addition of CeO 2 . Thus, the presence of CeO 2 in TiO 2 significantly enhanced the photocatalytic activity. Graphical Abstract