Structural and Electromechanical Behavior Evaluation of Polymer-Copper Nanocomposites

Gulfam Nasar,Muhammad Azhar Khan,Muhammad Farooq Warsi,Muhammad Shahid,Uzma Khalil,Muhammad Saleem Khan 한국고분자학회 2016 Macromolecular Research Vol.24 No.4

Copper nanoparticles were prepared by chemical reduction of copper nitrate by sodium borohydride as a reducing agent in de-ionized water/acetonitrile mixture. The prepared nanoparticles were incorporated in poly(vinyl alcohol) (PVA) by physical dispersion method to obtain PVA/copper nanocomposites. Various compositions of nanocomposites were obtained by changing the w/w ratio of nanoparticles with the polymeric material. The prepared nanocomposites cast into films of uniform thickness. The composite films were subjected to the electrical, mechanical and surface morphology characterization. AC Impedance was figured out by AC Impedance analyser. The results illustrated that copper nanoparticles impart electrical conductivity in poly(vinyl alcohol). Moreover, electrical conductivity of the composites exhibited an increase with an increase of w/w% of the copper nanoparticles in poly(vinyl alcohol). Tensile properties were studied in terms of tensile strength, elongation at break and Young’s modulus. Elongation at break and Young’s modulus values demonstrated an increase while tensile strength displayed a decrease at higher concentration of the copper nanoparticles in the composites. AFM results unfolded the surface morphology of the composites illustrating a smooth surface with evenly distributed copper nanoparticles in the polymer matrix. The dimensions of the uneven surface is attributed to the copper nanoparticles were estimated to be of a range less than 100 nm. The prepared nanocomposites are suggested as potential candidates in charge storing devices.

Zinc oxide-tungsten oxide (ZnO-WO3) composite for solar light-assisted degradation of organic dyes

Aziz Fatima,Warsi Al-Zoha,Somaily Hamoud H.,Din Muhammad Imran,Sabeeh Humera,Warsi Muhammad Farooq,Shakir Imran 한국화학공학회 2023 Korean Journal of Chemical Engineering Vol.40 No.6

Photocatalytic degradation of dyes is one of the most effective methods that can be utilized for a pollution-free environment. For this purpose, Tungsten oxide (WO3), zinc oxide (ZnO) and their composite WO3/ZnO were synthesized using facile route. X-rays diffraction (XRD), Fourier transform infra-red spectroscopy (FTIR) and scanning electron microscopy (SEM) confirmed their structural, spectral and morphological features, respectively. These techniques confirmed the formation of desired products. The as-prepared samples were utilized as photocatalysts for the evaluation of the photocatalytic removal of methylene blue and rhodamine B under solar light irradiation. The obtained results showed that the synergistic effect of tungsten oxide and zinc oxide is responsible for the increased charge separation and reduction in recombination chances of charge carriers that enhance the remarkable photocatalytic performance. For methylene blue and rhodamine-b, the percentage degradation was 94% and 85.7%, respectively. Different scavenger studies showed that holes are the major active species responsible for the removal of methylene blue. The EIS and Mott-Schottky plots confirmed the p-type and n-type character of WO3 and ZnO, respectively. Briefly, the as-synthesized nanocomposite showed enhanced photocatalytic behavior for the degradation of various dyes as compared to pristine metal oxides.

Photocatalytic degradation of crystal violet and benzimidazole using Ag-CoFe2O4 and its composite with graphitic carbon nitride

Amna Irshad,Muhammad Hassaan Arshed,H. H. Somaily,Humera Sabeeh,Noor‑ul‑Ain,Imtisal Ayman,Muhammad Farooq Warsi,Imran Shakir 한국고분자학회 2023 Macromolecular Research Vol.31 No.2

The classical co-precipitation technique was carried out for the preparation of cobalt ferrite (CFN), and Ag-doped cobalt ferrite (AgCFN). Composite with graphitic carbon nitride (AgCFN@gCN) was prepared by employing the ultrasonication method. Photocatalytic degradation activity of synthesized materials was evaluated using crystal violet (coloured compound) and benzimidazole (colourless compound) under sunlight. Various physiochemical methods such as UV–Visible, XRD, SEM, and FT-IR spectroscopy were employed for the characterization of prepared samples. XRD was used for structural characterization. The prepared nanomaterials were sized up to be < 09 nm. FT-IR spectroscopy was exploited for the functional group characterization. Surface morphology was perceived through Scanning Electron Microscope. Optical analysis was carried out using a UV–Visible spectrophotometer. The photodegradation efficiencies for crystal violet and benzimidazole were ascertained to be in the order of CFN < AgCFN < AgCFN@gCN, under sunlight. Among the synthesized photocatalysts, AgCFN@gCN was discovered to have the highest photocatalytic degradation efficiency of 52.72% and 84.21% for benzimidazole and crystal violet, respectively. The higher catalytic activity of AgCFN@gCN can be associated with its high surface area and the presence of active sites of the gCN sheets. Role of electrons (e−), holes (h+), and hydroxyl radicals (OH*) in the photocatalytic activity was also assessed.

Tungsten oxide-copper oxide supported on reduced graphene oxide as a proficient electrocatalyst with enhanced hydrogen evolution efficiency in an alkaline media

Katubi Khadijah Mohammedsaleh,Warsi Al-Zoha,Aziz Fatima,Khattak Zafar A.K.,Warsi Muhammad Farooq,Al-Buriahi M.S.,Alrowaili Z. A.,Yousaf Sheraz 한국물리학회 2023 Current Applied Physics Vol.51 No.-

This study focuses on the production of hydrogen through electrocatalysis using a newly synthesized and characterized nano-hybrid composite based electrocatalyst. The electrocatalyst is composed of mixed metal oxides and reduced graphene oxide. The electrocatalysts were evaluated for their structural and morphological characteristics through the implementation of diverse characterization methodologies. The utilization of electrochemical methodologies, including linear sweep voltammetry, Tafel slope, and electrochemical active surface area measurements, provided valuable information regarding the catalytic efficiency and effectiveness of the electrocatalysts for the hydrogen evolution reaction. The findings indicate that the electrocatalyst WO3–CuO/ rGO demonstrated exceptional catalytic efficiency, as evidenced by a current density of 200 mA/cm2 at an overpotential of -400 mV, a Tafel slope of 44 mVdec-1, and low charge transfer resistance. Additionally, the chronoamperometric analysis exhibited the electrocatalyst’s durability, highlighting its potential for practical implementations.

New Mg0.5CoxZn0.5xFe2O4 nano-ferrites: Structural elucidation and electromagnetic behavior evaluation

Maria Yousaf Lodhi,Khalid Mahmood,Azhar Mahmood,Huma Malik,Muhammad Farooq Warsi,Imran Shakir,M. Asghar,Muhammad Azhar Khan 한국물리학회 2014 Current Applied Physics Vol.14 No.5

In this work cobalt substituted magnesium zinc nanocrystalline spinel ferrites having general formula Mg0.5CoxZn0.5xFe2O4 where x ¼ 0.1, 0.2, 0.3, 0.4, 0.5 were synthesized using micro-emulsion technique. The Co substituted samples annealed at 700 C and characterized by various characterization techniques, such as X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), dielectric measurements and vibrating sample magnetometer (VSM). XRD analysis confirmed single phase spinel structure and the crystalline size calculated by Scherrer’s formula found to be in 21.38e45.5 nm range. The lattice constant decreases as substitution of Co is increased. The decrease in lattice constant is attributed to the smaller ionic radius of cobalt as compared to zinc ion. The FTIR spectra reveled two prominent frequency bands in the wave number range 400e600 cm1 which confirm the cubic spinel structure and completion of chemical reaction. The dielectric parameters were observed to decrease with the increased Co contents. The peaking behavior was observed beyond 1.8 GHz. The frequency dependent dielectric properties of all these nanomaterials have been explained qualitatively in accordance with Koop’s phenomenological theory. Magnetic studies revealed that the coercivity (Hc) attains maximum value of 818 Oe at w21 nm. The increasing trend of magnetic parameters (coercivity and retentivity) is consistent with crystallinity. The crystallite size is small enough to attain considerable signal to noise ratio in high density recording media. The optimized magnetic parameters suggest that the material with composition Mg0.5Co0.5Fe2O4 may have potential applications in high density recording media.