Pankaj Thakur

Preparation of BSA-ZnWO4 Nanocomposites with Enhanced Adsorptional Photocatalytic Activity for Methylene Blue Degradation

This study explains the effect of adsorption on dye degradation using bovine serum alum and ZnWO4 based nanocomposite (BSA-ZnWO4). The synthesis of BSA-ZnWO4 was performed by a hydrothermal method involving the encapsulation of ZnWO4 with BSA. BSA-ZnWO4 was characterized by SEM, TEM, XRD, FTIR, and UV-Vis spectral techniques. The photocatalytic experiments were performed under solar light. The dye removal was investigated under different reaction conditions. The photocatalytic efficiency of solar/BSA-ZnWO4 process was higher compared to solar/ZnWO4, dark/BSA-ZnWO4, solar/BSA, dark/ZnWO4, and solar light systems. The simultaneous adsorption and photodegradation process (A

Solar light-facilitated oxytetracycline removal from the aqueous phase utilizing a H2O2/ZnWO4/CaO catalytic system

Abstract A CaO-supported ZnWO4 nanocomposite (ZnWO4/CaO) was successfully synthesized using a novel hydrothermal method and was characterized by scanning electron microscopy (SEM), tunnelling electron microscopy (TEM), X-ray diffraction (XRD), electron diffraction X-ray (EDX), Fourier transform infrared spectroscopy (FTIR) and UV–visible (UV–vis) spectral analysis. The ZnWO4/CaO composites exhibited rod-like morphologies with variable lengths from 45 nm to 147 nm and diameters from 26 nm to 36 nm. The catalytic efficiency of the synthesized ZnWO4/CaO composites was displayed for the photodegradation of oxytetracycline (OTC) antibiotic from the aqueous phase. The synergistic degradation of OTC was investigated in the presence of H2O2 and ZnWO4/CaO. The rate of photodegradation followed pseudo-first-order kinetics. The antibiotic removal was strongly influenced by the catalyst loading, H2O2 concentration, pH and OTC concentration. Using a solar/H2O2/ZnWO4/CaO catalytic system, 85% COD removal was attained for OTC degradation in 210 min. The oxidative degradation occurred through hydroxyl radicals. The prepared nanocomposites possessed high recyclability and were easily separated from the aqueous solution by a simple sedimentation process.

Ggum-poly(Itaconic Acid) Based Superabsorbents Via Two-Step Free-Radical Aqueous Polymerization for Environmental and Antibacterial Applications

Ggum-based conducting hydrogels possessing dye removal and antibacterial property were developed by two-step free-radical aqueous polymerization method. Conductivity was introduced with polyaniline (PANI) chains incorporated within the crosslinked network of Ggum-poly(itaconic acid) superabsorbent. The material properties of the synthesized samples were characterized using FTIR spectroscopy, thermal analysis and scanning electron microscopy techniques. Results showed that synthesized samples exhibited the best antibacterial activity against Gram-positive bacteria. Synthesized samples were found to be effective in removal of toxic methylene blue (MB) dye from the waste water. The adsorption kinetics of superabsorbents has been described by using pseudo first and pseudo second order kinetics models. Furthermore, application of hydrogels to improve the water retention properties of different soils was also studied for agricultural purpose.

Array of bis-quaternary ammonium surfactant tailored Cu(2−x)Te quantum dots with amended functional assets

Building on previous work, many studies have focussed on metal chalcogenide nanomaterials for diverse applications such as photothermal ablation of tumor cells and photothermal therapy, etc. Despite the large amount of related work, the available literature suggests that the size-dependent morphological impacts and similar characteristics have not been proposed for the aforementioned variety of chalcogenides. Explicitly, we present a simple synthetic pathway for the synthesis of copper telluride [Cu(2−x)Te] nanoparticles (NPs) stabilized by highly hydrophobic surfactants. The structural, optical and electrical properties were examined in relation to the cumulative diameter of the copper telluride NPs using various surfactants. Transmission electron micrography (TEM) suggests the increasing hydrophobic character of the surfactants is a factor for the morphological changes in the copper telluride NPs. Electrical conductivity studies of copper telluride nanoparticles were carried out at room temperature. The current–voltage (I–V) curves are linearly symmetric towards the origin inferring that the contacts are ohmic and the resistance of the samples is in the range from 1–5 Ω. UV-vis spectroscopy gave optical band gap values of 3.42 eV, 3.40 eV and 3.37 eV for the (12-2-12), (14-2-14) and (16-2-16) capped copper telluride NPs, respectively. A change in the band gap with diameter demonstrates a blue shift, which may be attributed to a quantum size effect in the NPs. Broadening of the photoluminescence (PL) peak may suggest strain amongst the nanoparticles instigated by size induced quantization effects.

Semiconductor–Polymer Hybrid Materials

Semiconductor nanoparticles have attracted much attention due to their unique size and properties. Semiconductor–polymer hybrid materials are of great importance in the field of nanoscience as they combine the advantageous properties of polymers with the unique size-tunable optical, electronic, catalytic and other properties of semiconductor nanoparticles. Due to combination of the unique properties of organic and inorganic components in one material, these semiconductor–polymer hybrids find application in environmental, optoelectronic, biomedical and various other fields. A number of methods are available for the synthesis of semiconductor–polymer hybrid materials. Two methods, i.e. melt blending and in-situ polymerization, are widely used for the synthesis of semiconductor–polymer nanocomposites. The first part of this review article deals with the synthesis, properties and applications of semiconductor nanoparticles. The second part deals with the synthesis of semiconductor–polymer nanocomposites by melt blending and in-situ polymerization. The properties and some applications of semiconductor–polymer nanocomposites are also discussed.