Nanocomposite of CeO 2 and ZnO: An active material for the treatment of contaminated water Japinder Kaur a , Santosh Bhukal a , Kanu Gupta a , Mukesh Tripathy b , Sandeep Bansal c , Sonal Singhal a, * a Department of Chemistry, Panjab University, Chandigarh,160014, India b Icon Analytical Equipment (P) Ltd., New Delhi, India c Department of Science and Technology, New Delhi, India highlights graphical abstract CeO 2 /ZnO nanocomposites were fabricated using hydrothermal method. Photocatalytic efciency of CeO 2 /ZnO nanocomposites was compared with their monocomponent counterparts. Experimental conditions were opti- mized for the degradation of methy- lene blue dye. CeO 2 /ZnO nanocomposite proved to be a better candidate for the photo- catalytic degradation of dye. article info Article history: Received 30 January 2016 Received in revised form 30 March 2016 Accepted 18 April 2016 Available online 23 April 2016 Keywords: Composite materials Nanostructures Electron microscopy Photoluminescence spectroscopy abstract A series of catalytically active CeO 2 /ZnO nanocomposites with different molar ratio (CeO 2 : 1, 2, 3, 4, 5 and 6 mol%) were successfully synthesized by hydrothermal method. The synthesized nanocomposites were critically investigated using Powder X-ray diffraction technique, Transmission electron microscopy, Selected area electron diffraction and UVevis diffused reectance spectra analysis. Powder X-ray diffraction spectra revealed the presence of diffraction peaks of face-centered cubic phase of CeO 2 and hexagonal wurtzite phase of ZnO. Transmission electron microscopic analysis revealed that nano- composites consist of ZnO nanorods and CeO 2 nanoparticles; where, CeO 2 nanoparticles were clinging on the surface of ZnO nanorods. UVevis diffused reectance spectra analysis revealed the good absorption of all the samples towards UV light. The photocatalytic efciency of CeO 2 , ZnO and CeO 2 /ZnO was compared by using methylene blue dye as probe molecule. CeO 2 /ZnO nanocomposites were found to possess superior photocatalytic activity as compared to their monocomponent counterparts. Further- more, CeO 2 /ZnO with 5 mol% CeO 2 presented best photocatalytic performance. Additionally, inuence of different process variables on the rate of degradation of methylene blue was investigated using CeO 2 /ZnO with 5 mol% CeO 2 as catalyst. Maximum degradation of methylene blue was observed in alkaline region at a catalyst dosage of 1.00 g/L. © 2016 Elsevier B.V. All rights reserved. 1. Introduction Rising demands of modern society have resulted in manifold increase in production of dyestuff. However, this increased * Corresponding author. E-mail addresses: sonal1174@gmail.com, sonal@pu.ac.in (S. Singhal). Contents lists available at ScienceDirect Materials Chemistry and Physics journal homepage: www.elsevier.com/locate/matchemphys http://dx.doi.org/10.1016/j.matchemphys.2016.04.063 0254-0584/© 2016 Elsevier B.V. All rights reserved. Materials Chemistry and Physics 177 (2016) 512e520