سلام حسين علوان

In the current study, a series of reduced graphene oxide coated titanium dioxide nanocomposites (TiO2/rGO) were fabricated via a simple hydrothermal synthetic route using graphite flakes and titanium (IV) oxysulfate - sulfuric acid hydrate as precursors for rGO and TiO2 synthesis, respectively. The TiO2/rGO nanocomposites were fabricated with various weight ratios of rGO (5 %, 10 %, and 15 %) and their photocatalytic activity against Rhodamine B (RhB) dye removal was investigated. The composition, optical activity, morphology, and porosity of the obtained nanomaterials were determined using different techniques, including X-ray diffraction (XRD), Field emission scanning electron microscopy (FE-SEM), Transmission electron microscopy (TEM), Brunauer- Emmett-Teller (BET), UV-Vis diffuse reflectance spectroscopy (DRS) and Raman spectroscopy. Hence the XRD results showed that the TiO2/rGO nanocomposites were successfully fabricated. The TEM images exhibited the efficient distribution of TiO2 NPs on the rGO nanosheets. The significant structural changes in TiO2/rGO nanocomposites were reflected in the Raman spectra, indicating nanocomposite hybridization. The optical bandgap of the as-synthesized nanomaterials was slightly shifted from 3.14 eV (bare TiO2) to 2.75 eV (TiO2/rGO 15 %). Based on the photocatalytic degradation results, the best removal percentage of RhB dye was approached by TiO2/rGO (5 %) at optimum conditions ([RhB]= 15 ppm, pH 9, catalyst dose= 1.2 g/L, and irradiation time= 120 min). The highly efficient TiO2/rGO (5 %) nanocomposite showed enhanced photocatalytic behavior for the degradation of RhB dye, with a maximum removal percentage of (~94.55 %). Various reactive oxygen species (ROS) scavengers were employed to study the mechanism of photocatalytic degradation of RhB dye. The TiO2/ rGO (5 %) nanocomposite showed good cycling stability for five cycles

The presence of dyes in water is the most popular problem recently, so the current study was directed towards the synthesis of an effective material consisting of NiO and MWCNTs. The NiO/F-MWCNTs nanocomposite was synthesized using a simple hydrothermal method after functionalization of MWCNTs using sulfuric acid and nitric acid and utilized as an efficient surface to adsorption of malachite green dye from polluted water. The nanocomposite sample was characterized using several techniques are X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Thermogravimetric analysis (TGA), Field emission scanning electron microscopy (FESEM), High- resolution transmission electron microscopy (HRTEM), Brunauer–Emmett–Teller (BET) surface area analysis, Barrett-Joyner-Halenda (BJH) analysis and Energy dispersive X-ray (EDX). The analytical results showed that the prepared nanocomposite is of good crystalline nature with a particle size of 25.43 nm. A significant specific surface area was 412.08 m2/ g which indicates the effective impact of the nanocomposite in the adsorption of malachite green (MG) dye. On the other hand, the effect of adsorbent dose, temperature, acidic function and contact time on the adsorption efficiency of dye was studied. The kinetics of dye adsorption were also investigated employing two kinetic models, pseudo-first-order model and pseudo-second-order model. Finally, the thermodynamic functions were determined to identify the type of the reaction and the spontaneity of the process

In this paper, green and facile synthesis of sulfur- and nitrogen-codoped carbon nanospheres (CNs) was prepared from the extract of Hibiscus sabdariffa L by a direct hydrothermal method. Finally, sulfur-carbon nanospheres (CNs) were used as the adsorbent to remove Pb+2 ions from aqueous solutions because of the high surface area of S-CNs from CNs and N-CNs. .e synthesized nanospheres were examined by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), field emission scanning electron microscopy, transmission electron microscopy (TEM), and nitrogen adsorption-desorption isotherms. .e results show spherical shapes have a particle size of up to 65nm with a high surface area capable of absorbing lead ions efficiently. Additionally, the factors affecting the process of adsorption that include equilibrium time, temperature, pH solution, ionic intensity, and adsorbent dose were studied. .e equilibrium removal efficiency was studied employing Langmuir, Freundlich, and Temkin isotherm forms. .e kinetic data were analyzed with two different kinetic models, and both apply to the adsorption process depending on the values of correlation coefficients. .e thermodynamic parameters including Gibbs free energy (ΔG°), standard enthalpy change (ΔH°), and standard entropy change (ΔS°) were calculated for the adsorption process