G.H. Sonawane

Photocatalytic degradation of Rhodamine 6G using ZnO-montmorillonite nanocomposite: a kinetic approach

AbstractMontmorillonite clay was incorporated with ZnO to get ZnO-montmorillonite nanocomposite. This nanocomposite was successfully used for removal of Rhodamine 6G by photocatalytic degradation and adsorption. The influence of contact time, initial dye concentration, pH and catalyst dose has been determined. Contact time of 80 min and pH 3 was optimized for photocatalytic degradation of Rhodamine 6G. Kinetic parameters like pseudo-first-order, pseudo-second-order, Elovich and intraparticle diffusion model were determined. Pseudo-second-order kinetics could describe the adsorption kinetics well with r2 > 0.997 for 20–150 mg/L dye concentrations. Adsorption isotherms like Langmuir and Freundlich isotherm are used to describe the adsorption of dye. The monolayer capacity was observed to be 200 mg/g. Freundlich adsorption isotherm was found to fit better than Langmuir isotherm. Removal of Rhodamine 6G could be increased by combine effect of photocatalytic degradation and adsorption by nanocomposite.

Influence of rare-earth metal on the zinc oxide nanostructures: application in the photocatalytic degradation of methylene blue and p-nitro phenol

Abstract Rare-earth cerium (Ce)-doped zinc oxide (ZnO) spherical nanoparticles were synthesized by using the co-precipitation method. The doped materials were characterized by means of the X-ray diffraction, Williamson-Hall Plot, and field emission scanning electron microscopy analyses. The prepared nanoparticles exhibit a hexagonal wurtzite structure as observed from the XRD measurements. Energy dispersive X-ray spectroscopy data confirmed the purity of the prepared samples. The photocatalytic activity of the rare-earth Ce-doped ZnO spherical nanoparticles was investigated through the degradation of methylene blue (MB) and p-nitrophenol (PNP) solution under UV light radiation. Among the different amounts of dopant, 5 mole% Ce-doped ZnO nanoparticles showed the highest degradation with UV light radiation for both MB dye and PNP solution. The particle size, morphology, and separation of the photo-induced electron–hole pair are the main factors that influence photocatalytic activity. The probable mechanisms of photocatalytic degradation and mineralization of MB and PNP are also explained by liquid chromatography–mass spectrometry analysis.

Nanocomposites and Its Applications

Abstract In the recent past, nanocomposites have gained a great deal of attention due to their versatility. The present study reports on how some of the recent developments in nanocomposites can aid environmental protection through photocatalytic degradation of organics. Nanocomposites are prepared by three methods, intercalation, precipitation and evaporation. Techniques like SEM, TEM, XRD, EDS, Raman, IR spectroscopy are used to characterize nanocomposites. Nanocomposites drive the photocatalytic properties of the semiconductor-based nanomaterials in the visible range. They are also responsible for the separation of electron-hole pairs to enhance photocatalytic power nanomaterials. The combination of photocatalysis and photoinduced super hydrophilicity are applied for antibacterial sanitary surfaces through self-cleaning construction materials, odor-eliminating textiles, and pollutant-diminishing paints. In addition, there has recently been development toward multifunctional cotton fabrics with nanocomposite coating. Such fabric exhibits excellent antibacterial and UV blocking activities. Various types of clay, graphene, and graphene oxide are used as supports in nanocomposites. Nanocomposites of binary and ternary metal oxides, or heterostructures, can also be useful in photocatalysis and other applications.