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>

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>

High performing smart electrochromic device based on honeycomb nanostructured h-WO₃ thin films: hydrothermal assisted synthesis

Kondalkar, Vijay V.,Mali, Sawanta S.,Kharade, Rohini R.,Khot, Kishorkumar V.,Patil, Pallavi B.,Mane, Rahul M.,Choudhury, Sipra,Patil, Pramod S.,Hong, Chang K.,Kim, Jin H.,Bhosale, Popatrao N. The Royal Society of Chemistry 2015 Dalton Transactions Vol.44 No.6

<P>Herein, we report honeycomb nanostructured single crystalline hexagonal WO<SUB>3</SUB> (h-WO<SUB>3</SUB>) thin films in order to improve electrochromic performance. In the present investigation, honeycomb nanostructured WO<SUB>3</SUB> with different unit size and nanowire array with highly nanocrystalline frameworks have been synthesized <I>via</I> a hydrothermal technique. The influence of hydrothermal reaction time on the honeycomb unit cells, crystallite size, lithium ion diffusion coefficient and switching time for coloration/bleaching were studied systematically. The electrochromic study reveals that the honeycomb unit cell size has a significant impact on the electrochromic performance. Small unit cells in the honeycomb lead to large optical modulation and fast switching response. A large optical modulation in the visible spectral region (60.74% at <I>λ</I> = 630 nm) at a potential of −1.2 V with fast switching time (4.29 s for coloration and 3.38 s for bleaching) and high coloration efficiency (87.23 cm<SUP>2</SUP> C<SUP>−1</SUP>) is observed in the honeycomb WO<SUB>3</SUB> thin films with a unit cell diameter of 1.7 μm. The variation in color on reduction of WO<SUB>3</SUB> with applied potential has been plotted on an <I>xy</I>-chromaticity diagram and the color space coordinate shows the transition from a colorless to deep blue state.</P> <P>Graphic Abstract</P><P>Honeycomb nanostructured single crystalline hexagonal WO<SUB>3</SUB> (h-WO<SUB>3</SUB>) thin films in order to improve electrochromic performance. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c4dt02953d'> </P>

Nitrogen doped waste tea residue derived carbon dots for selective quantification of tetracycline in urine and pharmaceutical samples and yeast cell imaging application

Gunjal, Datta B.,Gurav, Yogesh M.,Gore, Anil H.,Naik, Vaibhav M.,Waghmare, Ravindra D.,Patil, Chandrashekhar S.,Sohn, Daewon,Anbhule, Prashant V.,Shejwal, Rajendra V.,Kolekar, Govind B. North-Holland 2019 Optical materials Vol.98 No.-

<P><B>Abstract</B></P> <P>In this work, waste tea residue, abundantly accessible, is utilized for synthesis of fluorescent carbon dots (CDs) by a simple, low cost and one step chemical oxidation method. The optical properties, surface functionality and particle size of CDs were ascertained by various techniques. The CDs exhibited excellent water solubility, optical properties, bioimaging ability etc. The fluorescence intensity of the CDs was diminished gradually with increasing concentrations of tetracycline drug owing to the inner filter effect (IFE) phenomenon. The developed fluorescent probe displayed a better linear range, excellent detection limit and interference free response to the tetracycline. This resulted in quantification of tetracycline in real sample which achieved almost 99% recoveries indicated excellent practical potential. Moreover, the CDs were used as fluorescent label for multicolour imaging of yeast cells which could open the doors for further research in biological fields.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Carbon Dots derived from waste tea residue by simple reflux method. </LI> <LI> Determination of Tetracycline by fluorescence quenching through inner filter mechanism. </LI> <LI> Simple, sensitive and interference free method. </LI> <LI> Carbon dots as a fluorescent label for multicolour cell imaging. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>Schematic of synthesis of CDs and inner filter effect based detection of tetracycline.</P> <P>[DISPLAY OMISSION]</P>

Enhanced Supercapacitive Performance of Chemically Grown Cobalt–Nickel Hydroxides on Three-Dimensional Graphene Foam Electrodes

Patil, Umakant M.,Sohn, Ji Soo,Kulkarni, Sachin B.,Lee, Su Chan,Park, Hyung Goo,Gurav, Kishor V.,Kim, J.H.,Jun, Seong Chan American Chemical Society 2014 ACS APPLIED MATERIALS & INTERFACES Vol.6 No.4

<P>Chemical growth of mixed cobalt–nickel hydroxides (Co<SUB><I>x</I></SUB>Ni<SUB>1–<I>x</I></SUB>(OH)<SUB>2</SUB>), decorated on graphene foam (GF) with desirable three-dimensional (3D) interconnected porous structure as electrode and its potential energy storage application is discussed. The nanostructured Co<SUB><I>x</I></SUB>Ni<SUB>1–<I>x</I></SUB>(OH)<SUB>2</SUB> films with different Ni:Co (<I>x</I>) compositions on GF are prepared by using the chemical bath deposition (CBD) method. The structural studies (X-ray diffraction and X-ray photoelectron spectroscopy) of electrodes confirm crystalline nature of Co<SUB><I>x</I></SUB>Ni<SUB>1–<I>x</I></SUB>(OH)<SUB>2</SUB>/GF and crystal structure consists of Ni(OH)<SUB>2</SUB> and Co(OH)<SUB>2</SUB>. The morphological properties reveal that nanorods of Co(OH)<SUB>2</SUB> reduce in size with increases in nickel content and are converted into Ni(OH)<SUB>2</SUB> nanoparticles. The electrochemical performance reveals that the Co<SUB>0.66</SUB>Ni<SUB>0.33</SUB>(OH)<SUB>2</SUB>/GF electrode has maximum specific capacitance of ∼1847 F g<SUP>–1</SUP> in 1 M KOH within a potential window 0 to 0.5 V vs Ag/AgCl at a discharge current density of 5 A g<SUP>–1</SUP>. The superior pseudoelectrochemical properties of cobalt and nickel are combined and synergistically reinforced with high surface area offered by a conducting, porous 3D graphene framework, which stimulates effective utilization of redox characteristics and communally improves electrochemical performance with charge transport and storage.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/aamick/2014/aamick.2014.6.issue-4/am404863z/production/images/medium/am-2013-04863z_0010.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/am404863z'>ACS Electronic Supporting Info</A></P>

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%.

Acetoclastic methanogenesis led by <i>Methanosarcina</i> in anaerobic co-digestion of fats, oil and grease for enhanced production of methane

Kurade, Mayur B.,Saha, Shouvik,Salama, El-Sayed,Patil, Swapnil M.,Govindwar, Sanjay P.,Jeon, Byong-Hun Elsevier Applied Science 2019 Bioresource Technology Vol. No.

<P><B>Abstract</B></P> <P>Fats, oil and grease (FOG) are energy-dense wastes that substantially increase biomethane recovery. Shifts in the microbial community during anaerobic co-digestion of FOG was assessed to understand relationships between substrate digestion and microbial adaptations. Excessive addition of FOG inhibited the methanogenic activity during initial phase; however, it enhanced the ultimate methane production by 217% compared to the control. The dominance of Proteobacteria was decreased with a simultaneous increase in Firmicutes, Bacteriodetes, Synergistetes and Euryarchaeota during the co-digestion. A significant increase in <I>Syntrophomonas</I> (0.18–11%), <I>Sporanaerobacter</I> (0.14–6%) and <I>Propionispira</I> (0.02–19%) was observed during co-digestion, which substantiated their importance in acetogenesis. Among methanogenic Archaea, the dominance of <I>Methanosaeta</I> (94%) at the beginning of co-digestion was gradually replaced by <I>Methanosarcina</I> (0.52–95%)<I>.</I> The absence/relatively low abundance of syntrophic acetate oxidizers and hydrogenotrophic methanogens, and dominance of acetoclastic methanogens suggested that methane generation during co-digestion of FOG was predominantly conducted through acetoclastic pathway led by <I>Methanosarcina</I>.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The addition of fats, oil and grease enhanced ultimate methane production by 217%. </LI> <LI> Firmicutes, Bacteriodetes, Synergistetes and Euryarchaeota were greatly increased. </LI> <LI> Dominance of <I>Methanosaeta</I> was replaced by <I>Methanosarcina</I> at the end of digestion. </LI> <LI> Methane was predominantly generated through acetoclastic pathway by <I>Methanosarcina</I>. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

An approach towards TiO2 chrysanthemum flowers with tunable properties: influence of reaction time in hydrothermal process

Patil, P. B.,Mali, S. S.,Kondalkar, V. V.,Khot, K. V.,Mane, R. M.,Hong, C. K.,Patil, P. S.,Kim, J. H.,Bhosale, P. N. Springer Science + Business Media 2015 Journal of materials science Materials in electron Vol.26 No.8

Temperature influenced chemical growth of hydrous copper oxide/hydroxide thin film electrodes for high performance supercapacitors

Patil, U.M.,Nam, Min-Sik,Lee, Su Chan,Liu, Shude,Kang, Shinill,Park, B.H.,Chan Jun, Seong Elsevier 2017 Journal of alloys and compounds Vol.701 No.-

<P><B>Abstract</B></P> <P>A hierarchical nanostructured hydrous copper oxide/hydroxide (CuO/(OH)<SUB>2</SUB>) with tuneable morphologies are grown on stainless steel (SS) as binder free, robust adhesive thin film electrode by chemical bath deposition (CBD) method. The influence of bath temperature on physico-chemical properties and electrochemical properties are studied. The morphology of the yields can be tailored only by controlling the reaction temperature of the bath and has shown prominence for the self-assembled growth leads transformation from hierarchical nano-bricks, nano-leaves to nanobuds nanostructures. Assisting from the distinctive structural characteristics, the resultant copper oxide/hydroxide nano-bricks, leaves and buds show superior electrochemical performance with specific capacitance values from ∼340 to 140 F g<SUP>−1</SUP> at 1 mA cm<SUP>−2</SUP>. The improved electrochemical performance of integrated binder free electrode signposts their potential capability in energy storage applications.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A facile synthesis of hydrous mixed phased CuO/(OH)<SUB>2</SUB> thin films using chemical bath deposition method. </LI> <LI> Variation in bath temperatures stimuluses the structural and morphological changes from Nano bricks to buds like structure. </LI> <LI> Structural and morphological changes influences the supercapacitive performance. </LI> <LI> The CuO/(OH)<SUB>2</SUB> nano-buds show superior electrochemical performance with notable specific capacitance values (∼340 F g<SUP>−1</SUP>). </LI> </UL> </P>