Browsing by Author "Mohamed, M.J.S."

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A facile microwave approach to synthesize RGO-BaWO4 composites for high performance visible light induced photocatalytic degradation of dyes
(2017) Mohamed, M.J.S.; Bhat, D.K.
Photocatalysts with enhanced efficiency for environmental remediation requires an effective separation of photogenerated electron hole pairs and optimum charge carrier transport. Based on the above criteria, a cost effective, facile one-pot microwave approach was made to synthesize RGO-BaWO4 composites with excellent stability and reusability in photodegradation of methylene blue (MB) and methyl orange (MO). A series of composites with varying composition with respect to RGO was synthesized and thoroughly characterized using various techniques. The composite with 2.5% RGO-BaWO4 showed maximum efficiency under visible light irradiation. The mechanism of charge transfer and kinetics of the reaction was also studied. The interfacial/interparticle charge transfer between the narrow elliptical BaWO4 particles and RGO is found to be responsible for the increased efficiency. The photo generated holes and the superoxide radical were found to play a key role in the degradation process. The synergistic action makes RGOBaWO4 composites a promising material as high performance photocatalyst for degradation of organic dyes. 2017 Denthaje Krishna Bhat, et al.
Novel NRGO-CoWO4-Fe2O3 nanocomposite as an efficient catalyst for dye degradation and reduction of 4-nitrophenol
(2018) Mohamed, M.J.S.; Shenoy, U, S.; Bhat, D.K.
Novel NRGO-CoWO4-Fe2O3 (N-doped reduced graphene oxide-cobalt tungstate-iron oxide) ternary nanocomposite was prepared by using simple microwave method. The synthesized materials were thoroughly characterized by X-ray diffraction (XRD) studies, Brunauer-Emmett-Teller (BET) analysis, transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, photoluminescence (PL) and UV-Visible spectroscopy. The nanocomposite was studied for its catalytic activity in degradation of methylene blue (MB) and reduction of 4-Nitrophenol (4-NP) to 4-Aminophenol (4-AP). The observed results of catalytic efficiency and rate constants indicated that the NRGO-CoWO4-Fe2O3 nanocomposite can perform as an excellent catalyst compared to other composite materials. The detailed experimental study revealed that this ternary nanocomposite shows a great promise as a candidate for various environmental applications. 2018 Elsevier B.V.
Novel ZnWO4/RGO nanocomposite as high performance photocatalyst
(2017) Mohamed, M.J.S.; Bhat, D.K.
In this study, we report the synthesis of nanocomposite material composed of zinc tungstate (ZnWO4) and reduced graphene oxide (RGO) as photocatalyst by a simple microwave irradiation technique. The prepared nanocomposites have been characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), energy dispersive X-ray (EDX) analysis, X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectrometer (FTIR), photoluminescence spectroscopy (PL) and UV-Visible spectroscopy. The photocatalytic activities of the prepared nanocomposites are evaluated in terms of the efficiencies of photodegradation of methylene blue (MB) dye in aqueous solution under visible light irradiation. The prepared nanocomposites showed excellent photodegradation efficiency compared to the commercial TiO2 under visible light irradiation. The activity of the catalyst towards methyl orange (MO) and rhodamine B (RB) was also good. Further, in view of the low cost, simple preparation method and high catalytic activity of the material, it is expected that the prepared nanocomposite can serve as an environment friendly photocatalyst for treating the large scale industrial waste waters. 2017 Denthaje Krishna Bhat, et al.