Influence of reduced graphene oxide-TiO₂ composite nanofibers in organic indoline DN350 based dye sensitized solar cells

Patil, Jyoti V.,Mali, Sawanta S.,Shaikh, Jasmin S.,Patil, Akhilesh P.,Patil, Pramod S.,Hong, Chang Kook Elsevier 2019 Synthetic metals Vol.256 No.-

<P><B>Abstract</B></P> <P>In this study, the highly efficient organic indoline DN350 based dye sensitized solar cells (DSSCs) have been fabricated using reduced graphene oxide (rGO)-TiO<SUB>2</SUB> composite nanofibers (NFs) and tested its photovoltaic properties. The influence of the rGO on the morphology, structural properties of the TiO<SUB>2</SUB> NFs have been characterized by various techniques. Our photovoltaic results revealed that the modified rGO-TiO<SUB>2</SUB> composite NFs exhibited higher power conversion efficiency (PCE) in comparison with the pristine-TiO<SUB>2</SUB> NFs. The electrochemical analysis indicated that the GO content provides more active sites results in higher dye adsorption which consequently improves the DSSCs performance. Our optimized sample containing 4 mg-rGO-TiO<SUB>2</SUB> NFs exhibited the best performance with 4.43% PCE, which is higher than the pristine-TiO<SUB>2</SUB> NFs (3.83%). Overall, this study presents the rGO-TiO<SUB>2</SUB> composite NFs as a novel strategy for enhancing the efficiency of the organic indoline DN350 based DSSCs.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Electrospun reduced graphene oxide (rGO)-TiO<SUB>2</SUB> composite nanofibers. </LI> <LI> rGO-TiO<SUB>2</SUB> composite nanofibers for organic indoline DN350 DSSCs. </LI> <LI> The 4.42% power conversion efficiency achieved for DSSC. </LI> </UL> </P>

Spherical crystallization of ezetimibe for improvement in physicochemical and micromeritic properties

Ashwini Patil,Yogesh Pore,Yogesh Gavhane,Shitalkumar Patil,Sachinkumar Patil 한국약제학회 2014 Journal of Pharmaceutical Investigation Vol.44 No.3

Spherical agglomerates of ezetimibe (EZT)were prepared with hydrophilic polymers; polyvinyl pyrrolidoneK30 (PVP) and/or poloxamer 188 (poloxamer) atdrug to polymer ratios of 1:1 (w/w) by spherical crystallizationtechnique, in order to improve its physicochemicaland micromeritic properties. Three different bridging liquids;chloroform, dichloromethane and/or ethyl acetatealong with good solvent acetone and poor solvent waterwere used to form six batches of agglomerates. Initialcharacterization of all batches in terms of micromeritic andphysicochemical properties resulted in optimization of (A3,EZT:PVP:ethyl acetate) and (B3, EZT:poloxamer:ethylacetate) batches and hence further investigated for drug–polymer interaction, crystallinity and morphology usingFTIR, XRPD, DSC and SEM techniques. The resultsindicated presence of hydrogen bonding, crystallinity andspherical shape in agglomerates. Therefore, the optimizedagglomerates (B3) were directly compressed into tablet. Unfortunately, drug release from the tablet was not satisfactory,suggesting a need of disintegrant from dissolutionpoint of view. Therefore, these agglomerates were recompressedincorporating certain excipients and evaluated asper pharmacopoeia. The dissolution rate of prepared tabletwas similar to that of marketed tablet (p[0.05). It couldbe concluded that spherical crystallization could be one ofthe effective and alternative approaches for improvedperformance of EZT and its tablet formulation.

Pethidine induced changes in ovarian follicular kinetics and biochemical parameters in albino rats

Patil, Somanath Reddy,Patil, Saraswati B,Malashetty, Vijaykumar B Kyung Hee Oriental Medicine Research Center 2006 Oriental pharmacy and experimental medicine Vol.6 No.4

Pethidine at the dose level of 0.5 mg and 0.75 mg/100 g body weight administered for 20 days to the cycling albino rats caused decrease in the ovarian weight and its protein content. The ovarian folliculogenesis in treated rats is hampered; as a result the follicles which are at the different stages of growth underwent regression. Therefore, the number of healthy follicles is reduced and atretic follicles increased. The elevated levels of ovarian cholesterol and decreased level of glycogen in the pethidine treated rats indicates the inhibition brought in steroidogenesis, which is dependent on pituitary gonadotrophins.

Antispermatogenic and antiandrogenic activities of various extracts of Melia azedarach Linn. seeds in albino rats

Patil, Sharanabasappa A.,Malashetty, Vijaykumar B.,Patil, Saraswati B. Kyung Hee Oriental Medicine Research Center 2003 Oriental pharmacy and experimental medicine Vol.3 No.3

Petroleum ether, chloroform and ethanol extracts of the seeds of Melia azedarach Linn. administered orally to male rats at the dose level of 25 mg/100 g body weight for 48 days showed antispermatogenic activity, as the number of spermatocytes, spermatids and spermatozoa was decreased. The total cholesterol content was increased while protein and glycogen contents were decreased. The acid phosphatase content was also decreased while that of alkaline phosphatase increased. At the same time the weight of caput and cauda epididymis, prostate gland, seminal vesicle and Levator Ani muscle was decreased indicating its antiandrogenic property. Of the three extracts, the petroleum ether extract was more potent in its antispermatogenic and antiandrogenic activities and did not produce any sings of toxicity upto a dose of 25 mg/100 g body weight oral administration. After subjecting it to preliminary phytochemical screening the petroleum ether extract showed positive tests for steroids and saponins.

Morphologically controlled electrodeposition of fern shaped Bi₂Te₃ thin films for photoelectrochemical performance

Patil, P.B.,Mali, S.S.,Kondalkar, V.V.,Mane, R.M.,Patil, P.S.,Hong, C.K.,Bhosale, P.N. Elsevier Sequoia 2015 Journal of Electroanalytical Chemistry Vol.758 No.-

Bismuth telluride (Bi<SUB>2</SUB>Te<SUB>3</SUB>) thin films have been proved to be important materials for thermoelectric application. Rapid development of photovoltaic materials has raised new hopes due to directly converting sun light to electricity. We report here a simple electrochemical synthesis route for the preparation of well-defined Bi<SUB>2</SUB>Te<SUB>3</SUB> nanostructures for photoelectrochemical solar cell application. Classification of crystal structure, surface morphology and elemental composition of resulting deposits were methodically characterized by X-ray diffraction (XRD) pattern, Raman spectroscopy, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM) and its photoelectrochemical performance (PEC). The potential range and electrochemical reactions relevant to the growth of Bi<SUB>2</SUB>Te<SUB>3</SUB> thin films were studied by cyclic voltammetry (CV). Furthermore, the influence of deposition variables such as applied deposition potential and effect of different surfactants (cationic, anionic and non-ionic) on morphology, crystal orientation associated with the film growth and photoelectrochemical performance were investigated systematically. The photoelectrochemical conversion efficiency recorded for Bi<SUB>2</SUB>Te<SUB>3</SUB> is 0.083%.

Tailor-made dicationic ionic liquid as a fluorescent sensor for detection of hydroquinone and catechol

Patil, Sandip K.,Patil, Suryakant A.,Vadiyar, Madagonda M.,Awale, Deepak V.,Sartape, Ashish S.,Walekar, Laxman S.,Kolekar, Govind B.,Ghorpade, Uma V.,Kim, Jin H.,Kolekar, Sanjay S. Elsevier 2017 Journal of molecular liquids Vol.244 No.-

<P>We are exploring a geminal dicationic ionic liquid (DCIL), 1,1'-(propane-1,3-diyl)bis(4-aminopyridin-1-ium) dihydroxide, [C-3(Amp)(2)][OH](2) as a fluorescent probe for detection of dihydroxybenzenes viz. hydroquinone (HQ) and catechol (CC). Simple and sensitive spectrofluorometric method is described which accomplished with efficient quenching of fluorescence of aqueous DCIL by dihydroxybenzenes. The sensor offers good linear detection range of 1-400 mu M and 1-1000 mu M with detection limits of 0.31 mu M and 0.40 mu M for HQ and CC, respectively. Under alkaline conditions HQ/CC oxidizes to corresponding benzoquinones which interact with DCIL and consequently quenching of fluorescence is occurred. This essential alkaline condition is in situ provided by purposefully tuned DCIL to having basic nature. The plausible quenching mechanism that involves photo-induced charge transfer pathway is evidently discussed. The proposed method is competent over a broad detection range. Selectivity of method is demonstrated by scrutinizing intervention of various interfering species. Recoveries from water sample analysis emphasize the possible use of DCIL probe in the detection of HQ and CC from water sources. The proposed method certainly confers a new approach in sensing techniques for dihydroxybenzenes. (C) 2017 Published by Elsevier B.V.</P>

Electrochemical Characterization of Si/Al Multilayer Thin Film Anode Materials for High Energy Lithium Secondary Batteries

Patil, Vaishali,Patil, Arun,Yoon, Seok-Jin,Choi, Ji-Won American Scientific Publishers 2018 Science of advanced materials Vol.10 No.4

<P>Nanostructured silicon is a promising material for high capacity anodes in lithium batteries, offering a specific capacity an order of magnitude beyond conventional graphite. But the large volume change of silicon during lithiation and delithiation and the resulting poor cyclability has prevented its commercial application. Herein, we report Si/Al multilayer thin film electrodes which are deposited on a Ni substrate by alternate sputtering of Si and Al at room temperature. Si/Al multilayer thin films are prepared using an RF magnetron sputtering method, and their potential use as anode materials for rechargeable lithium-ion batteries is investigated. The insertion of the Al layer into the Si layer improves the cycling performance. Si/Al multilayer thin films show an amorphous structure. The electrochemical characteristics of Si/Al multilayer film electrode can be controlled by the thickness, and number of stacked Si layers. Our prepared multilayer structures provided a promising research platform that may eventually lead to an optimized anode structure for advanced rechargeable lithium secondary batteries.</P>

Silver incorporated PEDOT: PSS for enhanced electrochemical performance

Patil, D.S.,Pawar, S.A.,Hwang, J.,Kim, J.H.,Patil, P.S.,Shin, J.C. Korean Society of Industrial and Engineering Chemi 2016 Journal of industrial and engineering chemistry Vol.42 No.-

A simple strategy is proposed for the development of silver (Ag) incorporated Poly (3,4-ethylenedioxythiophene):poly (styrene sulfonate) (PEDOT:PSS) electrodes for electrochemical supercapacitors. To examine the effects of the Ag on the specific capacitance and energy density of PEDOT:PSS, its concentration was varied from 0.3 to 1.5wt.% Ag. Surface morphology of the films is examined by field emission scanning electron microscopy, which revealed the smooth surface for PEDOT:PSS and existence of small Ag bright spots onto the smooth surface of PEDOT:PSS for the Ag-PEDOT:PSS. The electrochemical activity of PEDOT:PSS was enhanced after its interaction with Ag. An electrode with 0.9wt.% Ag in PEDOT:PSS showed superior specific capacitance (172Fg<SUP>-1</SUP>) and energy density (36.11WhKg<SUP>-1</SUP>) due to the synergistic effect of both Ag and PEDOT:PSS. These results were extensively examined using different characterization tools. This study will provide a new avenue for designing low cost and excellent electrochemical performance electrode based on Ag-PEDOT:PSS for better supercapacitors.

Anchoring MWCNTs to 3D honeycomb ZnO/GaN heterostructures to enhancing photoelectrochemical water oxidation

Patil, Santosh S.,Johar, Muhammad Ali,Hassan, Mostafa Afifi,Patil, Deepak R.,Ryu, Sang-Wan Elsevier 2018 Applied Catalysis B Vol.237 No.-

<P><B>Abstract</B></P> <P>Gallium nitride (GaN) is one of the ubiquitously known photoanode for photoelectrochemical water splitting (PEC-WS) due to its tunable band gap and favorable band edge positions. However, the unavoidable surface defects in GaN induces surface Fermi level pinning and surface band bending which severely reduces its PEC conversion efficiency. Constructing heterostructure is the key to approaching better charge separation efficiency and light harvesting ability for PEC-WS. Considering this, we have fabricated ternary heterostructure of GaN/ZnO/MWCNTs photoanode by combining metal organic chemical vapour deposition (MOCVD), hydrothermal and ‘dip and dry’ methods. FE-SEM results showed the formation of 3D hierarchical honeycomb structure of ZnO on GaN thin film surface when MWCNTs are added into hydrothermal reaction. We investigate the advantage of ZnO honeycomb structure in enhancing the solar PEC-WS performance of GaN photoanode. The synergy of incorporating MWCNTs has resulted into improvement in surface morphology, electron transportation and light harvesting capability. The as obtained ternary heterostructure exhibits photocurrent (<I>J</I> <SUB>ph</SUB>) of 3.02 mA/cm<SUP>2</SUP> at 0 V versus Pt electrode under 1-sun light illumination which is about 2.58 times higher than that of pristine GaN photoanodes (<I>J</I> <SUB>ph</SUB> = 1.14 mA/cm<SUP>2</SUP>).</P> <P><B>Highlights</B></P> <P> <UL> <LI> Constructing GaN/ZnO heterostructure enhances charge separation and PEC performance. </LI> <LI> MWCNTs act as structure directing agent and photosensitizer. </LI> <LI> MWCNTs modified porous hierarchical 3D honeycomb ZnO/GaN heterostructures are presented. </LI> <LI> The ternary heterostructure GaN/ZnO/MWCNTs promises unassisted water splitting. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>Synthesis of ternary heterostructure GaN/ZnO/MWCNTs with porous 3D hierarchical honeycomb structures has been demonstrated. As fabricated ternary heterostructure GaN/ZnO/MWCNTs photoanode promises unassisted PEC water splitting with enhanced photocurrent density of 3.02 mA/cm<SUP>2</SUP>, approximately ∼2.58 times higher than that of pristine GaN photoanode.</P> <P>[DISPLAY OMISSION]</P>

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>