*Corresponding author: Avvaru Praveen Kumar, Email: drkumar.kr@gmail.com Asian Journal of Nanoscience and Materials, 2018, 1(4), 271-281. Removal of Pb (II) from aqueous solution by gel combustion derived nano Co3O4- ZnO Iran Sheikhshoaie a, *, Azimeh Rezazadeh a, b , Samaneh Ramezanpour a, b a Department of Chemistry, Shahid Bahonar University of Kerman, Kerman, 76175, Iran b Young Research Society, Shahid Bahonar University of Kerman, Kerman, Iran. Received: 10 April 2018, Revised: 11 August 2018 and Accepted: 19 August 2018. ABSTRACT: Nano Co3O4/ZnO have been successfully synthesized by a simple and green gel combustion method followed by calcination at 600 o C. Sugar was used as fuel for combustion in this work. The nano Co3O4–ZnO were characterized by X-ray diffraction (XRD), Energy Dispersive X- Ray analysis (EDAX) and Scanning electron microscopy (SEM). Co3O4–ZnO was applied as an adsorbent to remove lead from aqueous solution. EDAX strongly proved the adsorption of lead on the surface of Co3O4-ZnO adsorbent. By increasing the amount of ZnO on the structure of the Co3O4-ZnO samples, the adsorption of Pb 2+ on the surface increased too. The SEM images also help the confirmation of lead adsorption on the surface of as synthesized samples. The concentrations of remained Pb 2+ ions were also measured by atomic absorption spectroscopy (AAS) and reported in the terms of removal efficiency. KEYWORDS: Gel combustion; Adsorption; Lead removal; Nanosized Co3O4/ZnO. GRAPHICAL ABSTRACT: In this study, we demonstrated the synthesis and characterization of a new composite Co3O4/ZnO nanostructure by a Gel combustion method. The results show this compound exhibits an enhanced high adsorption capacity to the Pb(II) ions. 1. Introduction By increasing heavy metals in the environment, heavy metals pollution has become a critical issue and attracted considerable attentions because of both acute and chronic toxicity [1]. Heavy metals have released to the environment by industrial manufacture such as pesticides, fertilizers, dyes, drugs, battery, tannery, fossil fuel, ceramic and glass industries printing [2,3]. Lead (Pb 2+ ), as a heavy FULL PAPER