The public discussion of the doctoral student (Ibrahim Hammadi Farhan) in the Department of Chemistry - College of Science - University of Anbar took place on Tuesday 6/6/2022 in Jaber Bin Hayyan Hall in the College of Science for his tagged thesis: -

(Synthesis of Composed Graphene Oxide/Metals Nanoparticle by Plasma Technology and Utilize as Sensors)

The study aims to  Due to the widespread relevance of graphene oxide (GO) and the chemical stability, conductivity, electrical, and thermal characteristics that this molecule exhibits. It has entered many fields, including industrial, biological, medical, agricultural and other fields. In addition to the ease of preparation and production in good quantities, this compound has entered many areas of research and development. Graphene oxide is preparing from graphite by Hummers method. GO is identifying by FTIR spectroscopy, where it gave the characteristic peak of 3400 cm-1 for the (C-OH) group, as well as the 1723 cm-1 for the (COOH) group, which are evidence of the transformation of graphite into graphene oxide. In addition, FESEM diagnosis, which gave a clear picture of graphene oxide, which shows the shape of its nanosheets. As well as the diagnosis of XRD, which gave a clear peak opposite the angle 2( = 11, which confirms the formation of graphene oxide. After that, (Cr, Co, Fe, and Mn) metal nanoparticles were prepared from their chloride salts using the plasma method, and through color changes, it is that these metals transformed into nanoparticles. In addition, the UV-Vsi diagnosis revealed peaks for those nanoparticles that were similar to measurements published in many studies, with particle wavelengths of Cr= 375nm, Co=341nm, Fe=496nm, and Mn=520nm. In addition to the FESEM diagnosis of these metallic nanoparticles, which between the diameters of the particles were within the nanoscale range (1-100nm), as well as the XRD diagnosis, which gave clear peaks for these metal nanoparticles compared to the published research. The graphene oxide nanocomposites and metal nanoparticles were prepared at a concentration of 100ppm of graphene oxide with 100ppm of metallic nanoparticles when the nanocomposites were composed of graphene oxide and only one metal. If the nanocomposite contains two nanometals, the concentration of each of them is 50ppm with 100ppm of graphene oxide. The nanocomposites were placed on a stirrer for 48 hours. The necessary samples were taken for diagnosing XRD, FESEM, and other samples were taken for carrying out applications as gas sensors for H2S, NO2. Through the values ??of resistance, sensitivity %, response time, and recovery time, the best nanocomposite can be determined and selected according to the above mentioned values.