Contents lists available at ScienceDirect Materials Science & Engineering B journal homepage: www.elsevier.com/locate/mseb Electrochemical property, antioxidant activities, water treatment and solar cell applications of titanium dioxide – zinc oxide hybrid nanocomposite based on graphene oxide nanosheet Nagi M. El-Shafai a,c, ⁎ , Mustafa Shukry b , Ibrahim M. El-Mehasseb c , Mahmoud Abdelfatah d , Mohamed S. Ramadan e , Abdelhamid El-Shaer d , Maged El-Kemary a a Institute of Nanoscience and Nanotechnology, Kafrelsheikh University, Kafr El-Sheikh 33516, Egypt b Department of Physiology, Faculty of Veterinary Medicine, Kafrelsheikh University, Egypt c Chemistry Department, Faculty of Science, Kafrelsheikh University, 33516, Egypt d Physics Department, Faculty of Science, KafrelSheikh University, 33516, Egypt e Chemistry Department, Faculty of Science, Alexandria University, Egypt ARTICLE INFO Keywords: Graphene oxide Nanoflower Antioxidant Electrochemical Solar cell Photocatalytic ABSTRACT Antioxidant activity has been detected with the HT22 mouse Hippocampal Neuronal cell line. The photocatalytic properties, electrochemical properties and solar cell applications tests of fabricated (Titanium dioxide (TiO 2 ) nanoparticles-Zinc oxide (ZnO) nanoparticle) hybrid nanocomposite based on Graphene oxide nanosheet (GO) have been studied with different techniques. The electrochemical properties revealed by cyclic voltammetry analysis and the photocatalytic study have been evidenced by the interaction of synthesized nanoflower com- posite (GO@TiO 2 ·ZnO) with mixed dyes (MB and RhB) and, also, with mixed pesticides (Tobaz and Metalxel). Absorbance intensities of examined organic pollution compounds were considerably quenched, this degradation was recorded by using the steady-state UV–Vis spectrophotometer under visible light source. Effect of fabricated GO@TiO 2 ·ZnO hybrid nanocomposite on the HT22 mouse Hippocampal Neuronal cell line was measured and the reducing power activity showed the potential antioxidant property of the fabricate nanocomposite. The results showed that the fabricated hybrid nanoflower composite on graphene oxide (GO) surface has high photocatalytic efficiency for degradation of mixed organic compounds, this composite has been kept the viability of HT22 cells line. The electron-hole pair recombination was evidenced by photoluminescence (PL) analysis, where the fab- ricated nanocomposite has high electron transfer, so, the tests of solar cell applications have been revealed and confirmed that the fabricated hybrid nanocomposite has activity towards solar cell applications. 1. Introduction Water treatment is one of the important fields in the last years due to the requirements for all human activities and water pollution is the biggest problem in life due to several sources of pollution, such as or- ganic dyes and pesticides [1]. There several methods for combating the pollutions of water such as adsorption, membrane separation used for removing pesticides from the aquatic environment [2,3]. While the photocatalytic degradation process by nanoparticles is an effective technology for converting pesticides and organic pollutants into en- vironmentally friendly compounds [4,5]. Titanium dioxide nano- particles one of the important nano-photocatalyst that used for re- moving organic and inorganic compounds, due to its wide energy gap, chemical and thermal stability, low cost, unique optical and electronic properties, ease of fabrication, and high surface area [4,5]. The com- bination of titanium dioxide nanoparticle with carbon nanostructures, such as carbon nanotube and graphene compounds has attention in nowadays years, graphene oxide with titanium dioxide (GO@TiO 2 ) nanocomposite has been used for enhanced the photocatalytic perfor- mance [6–9]. carbon nanostructure such as graphene oxide can work as an acceptor and transporter of the photogenerated electrons of semi- conductor nanoparticles (NPs), This combination is excellent mobility of charge carriers, specific surface area, unique optical and electronic properties. Highly toxic and widely insecticides, such as Tobaz and Metalxel were used for the protection of crops, where their mixture with soil and water [10] increase the concentration of these insecticides that make it more dangerous. Topaz and Metalaxyl are anti-fungal for vegetable crops, such as potatoes [11]. HT-22 is an immortalized mouse https://doi.org/10.1016/j.mseb.2020.114596 Received 23 March 2020; Received in revised form 7 May 2020; Accepted 31 May 2020 ⁎ Corresponding author. E-mail address: nagimohamed2016@gmail.com (N.M. El-Shafai). Materials Science & Engineering B 259 (2020) 114596 0921-5107/ © 2020 Elsevier B.V. All rights reserved. T