J. Water Environ. Nanotechnol., 4(1): 31-39 Winter 2019 RESEARCH ARTICLE Novel and ecofriendly synthesis of Ag-TiO 2 -G photocatalyst and investgate the efect of graphene in photodegradaton of an organic pollutant in water Farnosh Tavakoli, Alireza Badiei*, Jahan Bakhsh Ghasemi School of Chemistry, College of Science, University of Tehran, Tehran, Iran Received: 2018-08-15 Accepted: 2018-12-04 Published: 2019-02-01 ABSTRACT In this paper, Ag-TiO 2 -Graphene (Ag-TiO 2 -G) photocatalyst is synthesized via an economic and green rout. Pranus Cerasus is applied as a green reducing agent due to the presence of anthocyanin pigment. The anthocyanin molecules are responsible for the red color of the prunus cerasus seeds. The nanocomposites were characterized by XRD, EDS mapping, DRS and TEM. In order to explore the presence of Ag, diferent mass rato of Ag to in Ag-TiO 2 -G composite (5wt%, 10wt%, 15wt%, 20wt%, 25wt%, 30wt%, 35wt%, 40wt%, 45wt%, and 50wt%) were synthesized and their performance on the Acid Orange 7 (AO7) photodegradaton were compared with bare graphene. In additon, for investgaton of the presence of graphene, the Ag- TiO 2 was synthesized and compared with the Ag-TiO 2 -G composite from the photocatalytc performance point of view. Ag nanopartcles and graphene are two crucial factors in AO7 photodegradaton. Finally, we showed that photodegradaton of AO7 with photocatalyst depends on photogenerated holes. Keywords: Ag-TiO 2 -G; AO7; Green Synthesis; Photocatalyst; Pranus Cerasus How to cite this artcle Tavakoli F, Badiei A, Ghasemi BJ. Novel and ecofriendly synthesis of Ag-TiO 2 -G photocatalyst and investgate the efect of graphene in photodegradaton of an organic pollutant in water. J. Water Environ. Nanotechnol., 2019; 4(1): 31-39. DOI: 10.22090/jwent.2019.01.003 ORIGINAL RESEARCH PAPER Tis work is licensed under the Creative Commons Attribution 4.0 International License. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/. * Corresponding Author Email: abadiei@khayam.ut.ac.ir INTRODUCTION Pollution of water has become a dilemma in recent years. So, researchers are interested to fnd a way to eliminate pollution from wastewater and reuse it. For degradation of the organic pollutants, graphene-based photocatalysts are efective agents [1-3]. On the other hands, silver nanoparticles have excellent photocatalytic properties for the elimination of the water pollutants [4, 5]. Te placement of silver nanoparticles on the graphene improves the photocatalytic properties of these nanoparticles due to the superior electron mobility and high specifc surface area of graphene [6-8]. Graphene is a material with extraordinary properties [9, 10]. It should be noted that the nanoparticles are directly decorated on the graphene sheets without any molecular linkers. Terefore, many types of nanoparticles can be deposited on the graphene sheets and create interesting applications such as catalytic, energy storage, photocatalytic, and optoelectronic applications [11]. Tere are various methods for synthesis graphene composites, includes pre-graphitization, post-graphenization and syn-graphenization [12, 13]. Te TiO 2 nanoparticles have been used for photocatalytic elimination of dyes due to their extraordinary optical properties [14-16]. Te photocatalytic degradation mechanism of TiO 2 nanoparticles has been proven [17, 18]. One of the TiO 2 problems is the recombination of electrons and holes [19]. But, graphene can solve this problem of TiO 2 due to its amazing electron mobility and large surface area. On the other hand, graphene can act as an efcient transmitter and acceptor electron to improve photoinduced charge