Influence of graphene oxide on photocatalytic enhancement of cerium dioxide

• Main Authors: Duangdao Channei, Auppatham Nakaruk, Sukon Phanichphant
• Format: Journal
• Published: 2018
• Subjects: Materials Science; Agricultural and Biological Sciences; Arts and Humanities
• Online Access: https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85026348642&origin=inward; http://cmuir.cmu.ac.th/jspui/handle/6653943832/46819
• Institution: Chiang Mai University

© 2017 Graphene oxide (GO) was prepared by oxidizing purified natural flake graphite via modified Hummers method. The suspension of GO particles and cerium-based precursors were treated hydrothermally in order to prepare CeO 2 /GO composites. The disappearance of the [0 0 1] GO diffraction peak was observable in the XRD pattern for CeO 2 /GO composites because the crystal growth of CeO 2 between the interlayer of GO destroyed the regular layer stacking of GO phase. However XPS spectra of O 1 s core level and oxygen vacancies defect in CeO 2 caused the decrease in degree of crystallinity. Composite of CeO 2 with GO not only prevented the formation of extrinsic vacancies in the oxygen sub-lattice, but also prevented the switching from the major photoactive species Ce 4+ to Ce 3+ .The photocatalytic activity measurements demonstrated that the CeO 2 /GO composites exhibited much higher photocatalytic activity than CeO 2 for degradation of methylene blue (MB) under visible light irradiation. The enhancement of photocatalytic activity could be attributed to the excellently elevated absorption ability for the MB dye through π–π conjugation. As reported in PL results, the effective inhibition of the recombination of photogenerated electron–hole pairs due to the charge interaction between CeO 2 and GO.