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>

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>

Graphene-wrapped Ag 3 PO 4 /LaCO 3 OH heterostructures for water purification under visible light

Patil, Santosh S.,Mali, Mukund G.,Roy, Animesh,Tamboli, Mohaseen S.,Deonikar, Virendrakumar G.,Patil, Deepak R.,Kulkarni, Milind V.,Al-Deyab, Salem S.,Yoon, Sam S.,Kolekar, Sanjay S.,Kale, Bharat B. Elsevier 2016 Journal of energy chemistry Vol.25 No.5

<P>We demonstrated a unique synthesis approach of graphene (GR)-wrapped Ag3PO4/LaCO3OH (APO/LCO) heterostructures by an in-situ wet chemical method. FESEM analysis reveals the formation of rhombic dodecahedrons of APO decorated with LCO and later wrapped with GR flakes. Optical studies shows two absorption edges corresponding to the band gap energies of APO (2.41 eV) and LCO (4.1 eV). Considering the absorption edge of the heterostructures in the visible region, the photocatalytic activities of photocatalysts containing different APO/LCO mass ratios were evaluated by the degradation of MB. GR-decorated composite with 20% LCO (APO/LCO20/GR) exhibited the highest photocatalytic activity for MB degradation, with a rate constant, k of 0.541 min(-1). The photocatalytic activity of APO/LCO20/GR more greatly enhanced than those of the individual constituents (APO, LCO, APO/LCO20). The enhanced photocatalytic activity of the heterostructure can be attributed to the co-catalytic effect of LCO as well as intriguing physicochemical properties of GR. To understand the enhanced photocatalytic activity of the heterostructures the photocatalytic reaction mechanism is proposed in detail. The recyclability of the APO/LCO/GR composite photocatalyst is further evaluated by reusing the catalyst in replicate photocatalytic experiments which shows consistent photocatalytic activity thereby confirms the stability and reusability of heterostructure photocatalyst. (C) 2016 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.</P>

High-performance supercapacitor electrode based on a polyaniline nanofibers/3D graphene framework as an efficient charge transporter

Kulkarni, S.,Patil, U.,Shackery, I.,Sohn, J.,Lee, S.,Park, B.,Jun, S. Royal Society of Chemistry 2014 Journal of Materials Chemistry A Vol.2 No.14

The current paper describes chemically grown polyaniline (PANI) nanofibers on porous three dimensional graphene (PANI/3D graphene) as a supercapacitor electrode material with enhanced electrochemical performance. The chemical and structural properties of the electrode are characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy with confirmation of a semi-crystalline nature. The homogeneous growth of PANI on the 3D graphene network is visualized by field emission scanning electron microscopy (FESEM) and shows a nanofibers-based morphology. The maximum specific capacitance of the PANI/3D graphene electrode is found to be similar to 1024 F g(-1) in 1 M H2SO4 within the potential window of 150 to 800 mV vs. Ag/AgCl at 10 mV s(-1) scan rate (similar to 1002 F g(-1) at 1 mA cm(-2) discharge current density). The high surface area offered by the conducting, porous 3D graphene framework stimulates effective utilization of the deposited PANI and improves electrochemical charge transport and storage. This signifies that the 3D graphene framework is a proficient contender for high-performance capacitor electrodes in energy storage applications.

Electrochemical synthesis of flower like Mn-Co mixed metal oxides as electrode material for supercapacitor application

S.L. Kadam,S.M. Mane,P.M. Tirmali,S.B. Kulkarni 한국물리학회 2018 Current Applied Physics Vol.18 No.4

In the present work flower like Mn-Co mixed metal oxide electrode materials were successfully synthesized by simple, low cost electrodeposition method on stainless steel substrates. Different volume ratio of Mn-Co was used to attempt enhancement in the supercapacitive properties of electrode material. Structural, morphological and wettability properties of synthesized electrodes were carried out using XRD, RAMAN, FE-SEM and Contact Angle Measurement techniques. Electrochemical properties of electrodeposited Mn-Co mixed metal oxide at three different volume variation such as 50-50, 60-40 and 70- 30 electrodes were analyzed by using cyclic voltammetry, galvonostatic charge discharge and electrochemical impedance spectroscopy in 1M NaOH aqueous electrolyte. The Mn-Co:60-40 composition shows maximum specific capacitance which is 679 F/g at scan rate 5mV/sec. Charge discharge studies gives 95% columbic efficiency. Impedance spectroscopy reveals capacitive behavior and gives series resistance ~0.19 ohm and combined internal resistance ~0.89 ohm. The 80% retention of specific capacitance after the 1000 cycles. The synergistic effect of Mn-Co mixed metal oxide electrode having good conductivity, large surface area and improved charge transportation than individual electrode material leads to enhancing supercapacitor performance of electrode material for its practical application.

Modified physico-chemical properties and supercapacitive performance via DMSO inducement to PEDOT:PSS active layer

Lee, S.H.,Sohn, J.S.,Kulkarni, S.B.,Patil, U.M.,Jun, S.C.,Kim, J.H. Elsevier Science 2014 ORGANIC ELECTRONICS Vol.15 No.12

Poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) was treated with dimethyl sulfoxide (DMSO) in order to modify it physico-chemical properties in an effort to improve its electrochemical performance. In this study, the conductivity of PEDOT:PSS was controlled through post-solvent treatment in DMSO for various dipping times. The maximum conductivity of the DMSO-treated PEDOT:PSS electrode was ~1890Scm<SUP>-1</SUP>. The electrical conductivity, PEDOT to PSS ratio, chemical compositions, wettability, and surface roughness are correlated and suitably explained. The supercapacitive performance of the DMSO-treated PEDOT:PSS electrodes was studied in 1M H<SUB>2</SUB>SO<SUB>4</SUB> within an optimized potential window of 0 to -0.6V versus Ag/AgCl. The maximum specific capacitance of the PEDOT:PSS electrode treated in DMSO for 60min was found to be ~153Fg<SUP>-1</SUP> at a 1mAcm<SUP>-2</SUP> discharge current density (~145Fg<SUP>-1</SUP> at a 10mVs<SUP>-1</SUP> scan rate), along with an energy density of 93Whkg<SUP>-1</SUP> and a power density of 4.6kWkg<SUP>-1</SUP>.

Post-heating effects on the physical and electrochemical capacitive properties of reduced graphene oxide paper

Tamboli, S.,Kim, B.,Choi, G.,Lee, H.,Lee, D.,Patil, U. M.,Lim, J.,Kulkarni, S. B.,ChanJun, S.,Cho, H. Royal Society of Chemistry 2014 Journal of Materials Chemistry A Vol.2 No.14

We report combined electrochemical double-layer capacitance (EDLC) and pseudocapacitance in reduced graphene oxide (rGO) thick film like paper due to annealing temperature variations. The influence of annealing temperature (from room temperature (RT) to 1000 degrees C) on the structural, morphological, electrical, and electrochemical properties of rGO paper was evaluated. Upon increasing the annealing temperature, shifting of the dominant (002) X-ray diffraction (XRD) peak to a higher degree, volume expansion, and red-shifting of the G band in Raman spectra were observed. High-resolution transmission electron microscopy (HRTEM) images showed a reduction in the interlayer distance in rGO sheets from 0.369 to 0.349 nm as the annealing temperature increased from RT to 1000 degrees C; these results were congruent with the XRD results. According to X-ray photoelectron spectroscopy (XPS), the presence of hydroxyl, carboxyl, and other oxygen-containing groups decreased in samples annealed at higher temperatures. The attached functional groups, the electrical conductivity, and the supercapacitance of rGO papers were found to be mutually interrelated and could be tuned by varying the annealing temperature. The rGO paper annealed at 200 degrees C in a 1 M H2SO4 electrolyte at a scan rate of 50 mV s(-1) exhibited a maximum specific capacitance of 198 F g(-1).

Prenatal exposure to perfluorinated compounds affects thyroid hormone levels in newborn girls

Shah-Kulkarni, S.,Kim, B.M.,Hong, Y.C.,Kim, H.S.,Kwon, E.J.,Park, H.,Kim, Y.J.,Ha, E.H. Pergamon 2016 Environment international Vol.94 No.-

Perfluorinated compounds (PFCs) are ubiquitous in the environment and have been detected in humans and wildlife. Exposure to PFCs has decreased in the United States recently, while exposure to PFCs continues in Asian countries, which represents a public health concern. Various mechanisms by which PFCs affect fetal growth have been proposed, such as activation of peroxisome proliferators, disruption of thyroid hormones and changes in lipid metabolism. However, the overall evidence for an association with thyroid hormones is not strong. Therefore, we examined the effect of various prenatal PFCs on cord blood thyroid hormones: triiodothyronine (T3), thyroxine (T4), thyroid stimulating hormone (TSH) levels, and explored the endocrine disrupting effect of these PFCs on thyroid hormone levels in children according to gender. Two hundred and seventy-nine study participants were selected from among the enrolled participants in the Ewha Birth & Growth Retrospective Cohort, a retrospective birth cohort study conducted at Ewha Womans University Hospital, Seoul, Korea between 2006 and 2010. A generalized linear model was constructed to explore the association of PFCs and thyroid hormones. Further, an analysis stratified by gender was conducted. Our study shows that cord blood perfluoro n-pentanoic acid (PFPeA) was positively associated with cord blood T4 (p=0.01) level. Gender-specific analysis showed that prenatal PFCs: PFPeA and Perfluorohexane sulfonic acid (PFHxS) exposure significantly increased T4 (p<0.01) and T3 (p=0.03), respectively, while perfluorononanoic acid (PFNA) decreased TSH (p=0.04) concentration in newborn girls. Thus, prenatal PFC exposure may disrupt thyroid hormone homeostasis. Thyroid hormones play a crucial role in fetal development and may have gender specific action. Hence, these results are of utmost importance in high-risk groups, such as pregnant women and children.

Mutation analysis and characterisation of F9 gene in haemophilia- B population of India

Sujayendra Kulkarni,Rajat Hegde,Smita Hegde,Suyamindra S. Kulkarni,Suresh Hanagvadi,Kusal K. Das,Sanjeev Kolagi,Pramod B. Gai,Rudragouda Bulagouda 대한혈액학회 2021 Blood Research Vol.56 No.4

Background Hemophilia B (HB) is an X-linked bleeding disorder resulting from coagulation factor IX defects. Over 3,000 pathogenic, HB-associated mutations in the F9 gene have been identified. We aimed to investigate the role of F9 variants in 150 HB patients using sequencing technology. Methods F9 gene sequences were amplified from peripheral blood-derived DNA and sequenced on an Applied Biosystems (ABI) 3500 Sanger sequencing platform. Functional and structural predictions of mutant FIX were analyzed. Results Among 150 HB patients, 102 (68%), 30 (20%), and 18 (12%) suffered from severe, moderate, and mild HB, respectively. Genetic analysis identified 16 mutations, including 3 novel mutations. Nine mutations (7 missense and 2 stop-gain) were found to be pathogenic. Only 3 mutations (c.127C>T, c.470G>A, and c.1070G>A) were associated with different severities. While 2 mutations were associated with mild HB cases (c.304C>T and c.580A>G), 2 (c.195G>A and c.1385A>G) and 3 mutations (c.223C>T, c.1187G>A, and c.1232G>A) resulted in moderate and severe disease, respectively. Additionally, 1 mutation each was associated with mild-moderate (c.*1110A>G) and mild-severe HB disease (c.197A>T), 4 mutations were associated with moderate-severe HB cases (c.314A>G, c.198A>T, c.676C>T, and c.1094C>A). FIX concentrations were lower in the mutated group (5.5±2.5% vs. 8.0±2.5%). Novel p.E66D and p.S365 mutations were predicted to be pathogenic based on changes in FIX structure and function. Conclusion Novel single nucleotide polymorphisms (SNPs) largely contributed to the pathogenesis of HB. Our study strongly suggests that population-based genetic screening will be particularly helpful to identify risk prediction and carrier detection tools for Indian HB patients.

Hepatoprotective and antioxidant activities of crude fractions of endophytic fungi of Ocimum sanctum Linn. in rats

Shukla, S.T.,Kulkarni, V.H.,Habbu, P.V.,Jagadeesh, K.S.,Patil, B.S.,Smita, D.M. 경희한의학연구센터 2012 Oriental Pharmacy and Experimental Medicine Vol.12 No.2

Endophytic fungi are a rich source of novel organic compounds with interesting biological activities and a high level of biodiversity. In the present investigation, an attempt has been made to isolate, characterize and screen the Tulsi (Ocimum sanctum Linn.) root fungal endophytic fractions (TRF) for hepatoprotective and antioxidant activities. Endophytic fungi from Ocimum sanctum Linn. roots were isolated and cultured aseptically in PDA media. The full fledged grown fungus cultures were fermented in potato dextrose broth and fractionated using ethyl acetate. TRF-1 and TRF-2 were subjected free radical scavenging activities against 2,2-diphenyl-1-picrylhydrazyl, hydroxyl free radicals and reducing power assay. TRF-1 was found to be potential free radical scavenger with $IC_{50}$ values of $71.83{\mu}g/ml$ for DPPH and $110.85{\mu}g/ml$ for hydroxyl radical respectively. TRF-1 and TRF-2 were further assessed for hepatoprotective activity in $CCl_4$ induced hepatotoxicity in-vivo. Results showed that TRF-1 (200 mg/kg p.o.) and TRF-2 (200 mg/kg p.o.) significantly reversed the actions of carbon tetrachloride induced hepatotoxicity, as evident by restoration of serum AST, ALT, ALP, bilirubin, triglycerides and protein level to normal values as compared to $CCl_4$ treated group. Restoration of altered LPO (p<0.001), GSH (p<0.01) and catalase (p<0.01) by TRF-1 suggests that the hepatoprotective activity may be attributed to its antioxidant action. This was further supported by histopathological studies. TRF-1 was subjected to rDNA sequencing studies by PCR technique. Based on the morphological and molecular characterization, the fungus was identified as Paecilomyces variotti Bain. Therefore, endophytes from medicinal plants represent great potential for the discovery of new pharmacologically active metabolites.