Search

Porous carbon doped with transition metal oxides is rapidly becoming a key research topic in capacitive deionization desalination. This work reports a simple method for the synthesis of rGO doped with different ratios of nickel and cobalt oxides, i.e., 0, 10, 15, 25, 50, 75, and 100 wt%. The nanocomposite material was prepared via a modified Hammer`s method, followed by a hydrothermal doping process. The prepared samples were characterized using the X-Ray diffractometer (XRD), scanning electron microscope, energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), and Fourier transform infrared spectroscopy. TEM images revealed the arbitrary distribution of nickel and cobalt oxides in the rGO layer with an average particle size of 13 nm. The performance of the prepared materials was investigated ex situ, i.e., using a typical three-electrode cell. Also, it was verified in situ during the cell operation, i.e., using a two-electrode cell. Results showed that the performance of rGO was improved in the presence of Co3O4 and NiO nanoparticles as they form ternary Co3O4/NiO/rGO composites. Both XRD and EDX analyses confirmed the presence of Ni and Co in oxide form and attached to the rGO. The three-electrode cell measurements were from − 0.6 to 0.6 V in 1 M aqueous NaCl. The electrochemical measurements demonstrated that the rGO-25Ni, rGO-25Co, and rGO-15(50Ni-50Co) electrodes exhibited the best capacitive performance. Those samples achieved specific capacitances as high as 357 F g−1, 368.7 F g−1, and 461.5 F g−1, respectively. Such values are higher than those of electrodes based on rGO (82.77 F g−1), nickel oxide (2.98 F g−1), and cobalt oxide (3.8 F g−1). Better performance has been achieved using an equal ratio of bimetallic oxide loaded into the rGO than the single oxides or other ratios.

Transition metal oxide (TMO) nanoparticles are particularly important in capacitive deionization desalination due to their wide areas of application. The performance of rGO decorated with TiO2 nanoparticles has been investigated. Hammer method synthesizes the electrodes, followed by a hydrothermal treatment. The morphological properties of the rGO and rGO-15TiO2 were characterized by FE-SEM and TEM measurements. The TEM images indicated the random distribution of titanium oxides in the rGO layer, while SEM images showed that the TiO2 homogeneously covered and distributed on rGO sheets for rGO-15TiO2. The performance of the prepared nanocomposite electrode's electrochemical conduct was assessed by cyclic voltammetry (CV) ex-situ. In the three-electrode system, was observed from -0.6 to 0.6 V in 1 M aqueous NaCl. The results illustrated that rGO-15(TiO2) electrode showed the best performance in the CDI, achieving the highest specific capacitance of 473.9/g at 25mV/sec. The results indicating that rGO-15TiO2 is a novel electrode material for CDI.

Nanospheres with different particles size and nanorodes of copolymer of anthranilic acid with o-aminophenol poly(AA-co-o-AP) were synthesized by redox polymerization initiated by FeSO4.7H2O as redox initiator and ammonium peroxydisulfate (APS) as oxidant in different concentrations of aqueous solutions of hydrochloric acid. The influence of synthetic parameters such as acid concentration and the presence of redox initiator were investigated. The morphology and particles size were studied by transmission electron microscope (TEM) and scanning electron microscope (SEM). The results showed that the morphology and average particle size of polymeric nano particles according to SEM and TEM analyses were different based upon the conditions of the copolymerization. The physico-chemical characterization of the prepared nanoparticles was carried out by Fourier transform infrared spectroscopy (FT-IR), X-ray powder diffraction (XRD) and Thermogravimetric(TGA). Which FT-IR confirmed the structure of poly(AA-co-o-AP) nanoparticles in emeraldine form. The molecular weight was determined by gel permeation chromatography (GPC). The surface area of nanocopolymer particles was determined also by Brunauer-Emmett-Teller (BET). The competition of the prepared nano-sized copolymers particles towards the adsorption of copper ions from aqueous solutions was investigated. The results showed that the adsorption capacity was based on particle size of nanocopolymers and their surface area. The adsorption capacity increased with decreasing the particle size. On the other hand the adsorption capacity increased with increasing the surface area and the molecular weight of the prepared nano-sized copolymers of poly(AA-co-o-AP).

Nanorodes, nanosheets, nanospheres and nano-amorphous shape with different particles size of copolymer of anthranilic acid with o-phenylenediamine poly(AA-co-o-PD) were synthesized by redox polymerization initiated by FeSO4.7H2O as redox initiator and ammonium peroxydisulfate (APS) as oxidant in different concentrations of aqueous solutions of hydrochloric acid. The influence of synthetic parameters such as acid concentration and the presence of redox initiator were investigated. The morphology and particles size were studied by transmission electron microscope (TEM) and scanning electron microscope (SEM). The results showed that the morphology and average particle size of polymeric nano particles according to SEM and TEM analyses were different based upon the conditions of the copolymerization. The physico-chemical characterization of the prepared nanoparticles was carried out by Fourier transform infrared spectroscopy (FT-IR), X-ray powder diffraction (XRD). Which FT-IR confirmed the structure of poly(AA-co-o-PD) nanoparticles in emeraldine form. The molecular weight was determined by gel permeation chromatography (GPC). The surface area of nanocopolymer particles was determined also by Brunauer-Emmett-Teller (BET). The competition of the prepared nano-sized copolymers particles towards the adsorption of copper ions from aqueous solutions was investigated. The results showed that the adsorption capacity was based on particle size of nanocopolymers and their surface area. The adsorption capacity increased with decreasing the particle size. On the other hand the adsorption capacity increased with increasing the surface area of the prepared nano-sized copolymers of poly(AA-co-o-PD).

The prepared glass samples within the composition (85-x) TeO2-xB2O3-5Bi2O3-5SrCl2-5LiF (TBBSL) with x = 0, 10, 20, 30, 40, 50 and 60 mol% were synthesized. The X-ray diffraction patterns (XRD) showed the amorphous nature of the system. The density (ρ), molar volume (vm) and oxygen packing density (OPD) have been measured and calculated. The Fourier Transform Infrared (FTIR) of TBBSL glasses showed the presence of TeO3, TeO4, BO3, BO4, LiF, SrO and BiO6. Also, FTIR spectra identified that the substitution of B2O3 with TeO2 in glass system led to convert the TeO4 to TeO3 and the formation of bridging structure Te-O-B with increasing the B2O3 mol%, consequently the BO4 units convert to BO3 and so the number of non-bridging oxygen (NBO) increases. The optical band gaps (Eopt), the Urbach energy (ΔE) and refractive index (n) have been calculated from optical absorption spectra. Thermal characterization was determined by using Differential Scanning Calorimetry (DSC) at different heating rates 10, 15, 20, 25 °C/min. The prepared glasses showed high thermal stability. High reflective index and higher thermal stability made the synthesized glass system is a suitable candidate for the large bulk glass and optical fiber production. Keywords: Oxyhalide tellurite glasses, FTIR, Uv–vis spectroscopy, Thermal analysis

The complexes derived from reaction of copper(II) salts (Cl−, Br−, CH3COO− and SO 4 −2 ) 2-(3-Amino-4,6-dimethyl-1H-pyrazolo[3,4-b]pyridin-1-yl)acetohydrazide were prepared and characterized. Different standardized instruments were used for obtaining the required data (spectral method UV–Vis., IR, 1H-NMR, mass spectra) magnetic susceptibility and thermogravimetric analysis TGA were performed. The electronic spectral data and magnetic moment values proved that all the copper complexes have octahedral geometry. CuO nanoparticles with 15.5 nm of particle size have been synthesized via solid state thermal decomposition using these copper (II) complexes as new precursors. Surface morphology of the synthesized CuO nanoaprticles were investigated by Ultraviolet visible light spectroscopy (UV–Vis), X-ray diffraction, X-ray photoelectron spectroscopy, and scanning electron microscopy. The photocatalytic activity of CuO nanoparticles was assessed toward photocatalytic degradation of MB dye and the results exhibited 97 % efficiency with degradation rate of 0.018 min−1.

Capacitive deionization (CDI) technology has received great attention in water desalination. In this study, the performance of reduced graphene oxide (rGO) decorated with TiO2 nanoparticles (NPs) was investigated. Electrodes were synthesized via a modified Hummers’ method followed by a hydrothermal treatment step. Different TiO2 percentage (0, 10, 15, 25, 50, 75, and 100 wt% with respect to rGO) were investigated. The morphology, surface area, wettability, crystal structure and chemical composition of the as-prepared materials were characterized. Transmission electron microscopy (TEM) images indicated the homogeneous distribution of TiO2 on the rGO sheets with an average particle size of 9.3 nm. The performance of the prepared rGO-xTiO2 nanocomposite electrodes in terms of electrochemical behavior was evaluated by cyclic voltammetry (CV) experiments. The results illustrated that among all the prepared rGO-xTiO2 electrodes, the rGO-15TiO2 electrode showed the best performance in CDI, because of the significant improvement in its hydrophilicity and surface area. The rGO-15TiO2 electrode achieved the highest specific capacitance of 635.1 F/g, corresponding to 7 and 19 times greater than those of the rGO- (87.77 F/g) and TiO2-based (7.039 F/g) electrodes, respectively. These results indicate excellent potential for the application of this electrode in CDI and energy storage.

Capacitive deionization (CDI) desalination has attracted much attention due to innovations in electrode manufacturing. Hybrid electrodes exhibit a relatively high capacity for salt ion removal, a fast rate of ion adsorption, and good permanence. In this study, a combination of reduced graphene oxide (rGO), Co, and titanium oxide nanoparticles (10 rGO-1Co-xTiO2, x = 1∼9) was used to create a nanocomposite that was investigated as a possible electrode candidate for CDI. The crystalline structure, surface morphology and chemical bonding of the prepared nanocomposite samples have been examined by XRD, TEM, FE-SEM, and FT-IR. Electrochemical measurements were carried out to estimate the capacitive behavior of the different electrodes. The analysis of Co/rGO-xTi confirmed the incorporation of Co and Ti oxides into the rGO nanosheets. The cyclic Voltammetry results showed that Co/rGO-Ti7 had the best performance in terms of capacitance (720 F/g) and salt removal, reaching 12.48 mg/g, indicating its potential use as an electrode in CDI systems. The high performance was related to the synergistic effect of both Ti and Co oxides intercalated inside the rGO support.

Cost-effective, scalable and efficient electroactive material for ion-selective electrode was developed. Facile nanocomposite composed from montmorillonite clay layers and polyaniline nanofibers (PANI-NFs) was facilely prepared at ambient condition. The polyaniline nanofibers were polymerized on the surface of montmorillonite clay. Then the prepared nanocomposite was used as efficient electroactive modifier for developing new sensitive and selective modified carbon paste electrodes (CPE) for potentiometric determination of Clomipramine hydrochloride (CLO-HCl) in pure and pharmaceutical formulations. Effects of experimental parameters such as paste composition, response time, selectivity, pH and temperature on the potential response of CLO-HCl electrode were investigated. The paste incorporating 5 (electrode I) and 10 (electrode II) mg of developed nanocomposite (MT-PANI-NF) showed the best experimental performance, exhibiting the best Nernstian slope values of 60.30 ± 0.28 and 60.00 ± 0.22 mV decade−1 over a considerable spacious concentration range from 1.0 × 10−5 to 1.0 × 10−2 mol L−1 over pH range from 3.5 to 7.5. Additionally, a fast dynamic response time of 9 and 7 s for electrode I and II, respectively, was achieved. The proposed sensors displayed good discriminating capability toward CLO-HCl with regard to a number of interfering materials. The interaction between MT-PANI-NF nanocomposite and CLO-HCl drug at the electrode surface was studied through scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX). The results were obtained using those electrodes were in a good agreement with those which were obtained using the official method. The method was validated according to IUPAC recommendation parameters.