Green approach for hierarchical nanostructured Ag-ZnO and their photocatalytic performance under sunlight

Patil, S.S.,Mali, M.G.,Tamboli, M.S.,Patil, D.R.,Kulkarni, M.V.,Yoon, H.,Kim, H.,Al-Deyab, S.S.,Yoon, S.S.,Kolekar, S.S.,Kale, B.B. Elsevier Science Publishers 2016 CATALYSIS TODAY - Vol.260 No.-

<P>In this study, the synthesis of silver-zinc oxide (Ag-ZnO) nanostructures with a plant-extract-mediated hydrothermal method was investigated. The eco-friendly plant extract Azadirachta indica (Neem) was used as a reducing agent. The X-ray diffraction patterns showed the formation of face-centered cubic (fcc) Ag nanoparticles (NPs) and a wurtzite ZnO structure. An optical study of these nanostructures revealed two absorption edges: one at 393 nm corresponding to ZnO and the other at approximately 440 nm corresponding to Ag. A morphology study showed that hierarchical ZnO nanostructures were decorated with 10-50-nm-diameter Ag NPs. The formation and growth mechanism were also examined. A photoelectrochemical study was performed to investigate the electronic interactions between the ZnO and Ag NPs in the photoanode upon exposure to light. The Ag NPs act as electron acceptors, inhibiting electron-hole recombination. The photocatalytic activity of the Ag-ZnO nanostructures was examined by observing the degradation of aqueous methylene blue (MB) dye under natural sunlight. The apparent rate constant determined for the photocatalytic degradation of MB by the Ag-ZnO nanostructures was 5.9668 x 10(-2) min(-1), which was faster than that of the untreated ZnO nanostructures (2.527 x 10(-2) mm(-1)). This plant-extract-mediated synthetic route could also be applied to the synthesis of other Ag-semiconductor oxide nanostructures. (C) 2015 Elsevier B.V. All rights reserved.</P>

Confinement of Ag₃PO₄ nanoparticles supported by surface plasmon resonance of Ag in glass: Efficient nanoscale photocatalyst for solar H₂ production from waste H₂S

Patil, S.S.,Patil, D.R.,Apte, S.K.,Kulkarni, M.V.,Ambekar, J.D.,Park, C.J.,Gosavi, S.W.,Kolekar, S.S.,Kale, B.B. Elsevier 2016 Applied Catalysis B Vol.190 No.-

<P>Ag3PO4 is a good photocatalyst but ubiquitously known for its photocorrosion problem during photocatalytic reaction. Therefore, stabilization of Ag3PO4 with retaining its fundamental properties has immense importance. With this motivation, we designed Ag3PO4 glass nanocomposite to resolve the problem of photocorrosion. Moreover, the effect of size quantization on photocatalytic activity has also been demonstrated by growing the cubic Ag3PO4 nanoparticles with size in the range of 3-9 nm in glass matrix via melt and quenching method. The band gap of Ag3PO4 has been tuned (2.56-2.25 eV) in glass matrix with respect to size. Considering the size tunable band gap of Ag3PO4 glass nanocomposite within visible region, it is demonstrated as a photocatalyst for hydrogen (H-2) production from copious hazardous waste H2S. The utmost H-2 production i.e. 3920.4 mu mol h(-1) g(-1) is obtained using 1 gm of Ag3PO4 glass nanocomposite powder. The apparent quantum yield for H-2 production is calculated to be 5.51% for Ag3PO4 glass nanocomposite. Interestingly, presence of plasmonic Ag was also observed in Ag3PO4 glass nanocomposite which contributes for H-2 production through enhanced light absorption, efficient charge separation and improved stability. Recycling study of sample reveals stable H-2 production efficiency and good stability of the photocatalyst. Surprisingly, catalyst can be reused many times and recovery of catalyst is possible just rinsing with distilled water. All these results demonstrate directly the feasibility of designing a new generation photocatalysts. (C) 2016 Published by Elsevier B.V.</P>

Structural, Optical and Thermo Electrical Properties of Nanostructured Vacuum Evaporated CdS Thin Films

M.S. Kale,Y.R. Toda,M.P. Bhole,D. S. Bhavsar 대한금속·재료학회 2014 ELECTRONIC MATERIALS LETTERS Vol.10 No.1

Nano structured thin films having different thickness of CdS were deposited by thermal evaporation techniques, onto precleaned amorphous glass substrate at room temperature. The structural properties of films were evaluated by XRD, Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM). The quantitative analysis was done by Energy Dispersive Analysis for x-ray to determine atomic % of the material used. The optical band gaps of the films were measured by using optical absorption spectra. Thermo Electrical parameters such as Fermi energy (0.098 to 0.006 eV), absorption coefficient (1.04 to 1.16) have been estimated. The x-ray diffraction analysis confirms that films are polycrystalline in nature having orthorhombic structure with a preferential orientation along the (040) plane. The degree of such a preferred orientation was found to increase with film thickness. The lattice parameters (a = 14.315, b = 14.568 and c = 14.074 Å) and crystallite size (D) were calculated and found to be 242.9 nm. Unit cell volume is found to be 2935. SEM investigation confirms that films were uniformly deposited over the surface and particles were granular in nature. The particle size was determined by using SEM and found to be 6.88 -10.8 6 nm. It is found that CdS is direct band gap material having value of 2.42 eV.

A new layer perovskites Pb₂Ga₂Nb₂O₁₀ and RbPb₂Nb₂O₇: An efficient visible light driven photocatalysts to hydrogen generation

Kanade, K.G.,Baeg, J.O.,Kong, K.j.,Kale, B.B.,Lee, S.M.,Moon, S.J.,Lee, C.W.,Yoon, S. Pergamon Press ; Elsevier Science Ltd 2008 INTERNATIONAL JOURNAL OF HYDROGEN ENERGY - Vol.33 No.23

We report here the novel approach to synthesis of layer perovskite photocatalysts, Pb<SUB>2</SUB>Ga<SUB>2</SUB>Nb<SUB>2</SUB>O<SUB>10</SUB> and RbPb<SUB>2</SUB>Nb<SUB>2</SUB>O<SUB>7</SUB> using solid state route (SSR) and molten salt synthesis (MSS) method. The reported modified MSS method has advantage over conventional SSR method for uniform particle size, well-defined crystal structure, controlled morphology and stoichiometry vis-a-vis photocatalysis. The structural study was performed using X-ray difractometry (XRD) and computation based on density functional theory (DFT). The simulation study showed that both the compounds belong to the Ruddlesden-Popper phase (A'<SUB>2</SUB>A<SUB>n-1</SUB>B<SUB>n</SUB>O<SUB>3n+1</SUB>; n=2 or 3). The surface morphology of the materials was studied using field emission scanning electron microscope (FESEM) and high resolution transmission electron microscope (HRTEM). The average particles size of perovskites Pb<SUB>2</SUB>Ga<SUB>2</SUB>Nb<SUB>2</SUB>O<SUB>10</SUB> and RbPb<SUB>2</SUB>Nb<SUB>2</SUB>O<SUB>7</SUB> was in the range 20-40 and 70-90nm respectively. The efficacy of these materials was studied to particle size and morphology as a visible light driven photocatalyst for the hydrogen generation from H<SUB>2</SUB>S. Electronic band structure with DOS has also been performed for both the materials. Being a stable single-phase ternary-layered oxide perovskites and band gap (2.75eV) in visible domain, they may have potential applications in electronic devices as well.

Mesoporous Mn₂O₃/reduced graphene oxide (rGO) composite with enhanced electrochemical performance for Li-ion battery

Jadhav, Harsharaj S.,Thorat, Gaurav M.,Kale, Bharat B.,Seo, Jeong Gil Royal Society of Chemistry 2017 Dalton Transactions Vol. No.

<▼1><P>Transition metal oxides are the most promising candidates in low-cost and eco-friendly energy storage/conversion applications.</P></▼1><▼2><P>Transition metal oxides are the most promising candidates in low-cost and eco-friendly energy storage/conversion applications. Herein, bare Mn2O3 and a Mn2O3/reduced graphene oxide (rGO) composite have been synthesized by a facile chemical co-precipitation and subsequent annealing procedure. The synthesized Mn2O3/rGO composite exhibits a porous microcube structure formed with several interconnected particles. The porous Mn2O3/rGO composite, with high surface area and increased conductivity, facilited the charge transfer to enhance the overall electrochemical performance when applied as an anode material in Li-ion batteries. The porous Mn2O3/rGO composite exhibits a highly reversible lithium storage capacity of 1015 mA h g<SUP>−1</SUP> at a rate of 0.5 C (230 mA g<SUP>−1</SUP>) during 130 cycles with excellent cycling stability and rate capability. The superior electrochemical performance results mainly due to the combined effect of rGO and Mn2O3, which offers high conductivity, faster Li<SUP>+</SUP> ion transfer, and enhanced structural stability. The material synthesis strategy presented in this study is simple, cost-effective and scalable, which can open new avenues for large-scale applications of composites of graphene and other transition metal oxides.</P></▼2>

Perfluorinated polysiloxane hybridized with graphene oxide for corrosion inhibition of AZ31 magnesium alloy

Ikhe, A.B.,Kale, A.B.,Jeong, J.,Reece, M.J.,Choi, S.H.,Pyo, M. Pergamon Press 2016 Corrosion science Vol.109 No.-

Perfluorinated polysiloxane [-(SiR<SUB>1</SUB>R<SUB>2</SUB>-O)<SUB>n</SUB>-, where R<SUB>1</SUB> is -OH and R<SUB>2</SUB> is -CH<SUB>2</SUB>)<SUB>2</SUB>-(CF<SUB>2</SUB>)<SUB>5</SUB>-CF<SUB>3</SUB>], was synthesized from 1H,1H,2H,2H-perfluorooctyltriethoxysilane (PFOTES) and hybridized with graphene oxide (GO). The composite (PPFS/GO) was applied to AZ31 Mg alloy for corrosion protection in NaCl. Efficient inhibition by PPFS/GO was realized due to a synergistic effect via the remnant hydrophobic-properties of PFOTES and the high surface area of GO. The polymeric nature of PPFS also contributed to the strong adhesion between the coating layer and AZ31, making this work different to most previous reports where the Mg surface was pretreated before coating.

An Integrative Approach for Identifying a Metabolic Phenotype Predictive of Individualized Pharmacokinetics of Tacrolimus

Phapale, P B,Kim, S-D,Lee, H W,Lim, M,Kale, D D,Kim, Y-L,Cho, J-H,Hwang, D,Yoon, Y-R Springer Science and Business Media LLC 2010 Clinical pharmacology and therapeutics Vol.87 No.4