Mesoporous architecture of TiO2 microspheres via controlled template assisted route and their photoelectrochemical properties

Bhat, T. S.,Mali, S. S.,Korade, S. D.,Shaikh, J. S.,Karanjkar, M. M.,Hong, C. K.,Kim, J. H.,Patil, P. S. Springer Science + Business Media 2017 Journal of materials science. Materials in electro Vol.28 No.1

<P>Anatase titanium dioxide (TiO2) microspheres were successfully synthesized via a controlled chemical route using carbon spheres as sacrificial templates. The morphology has been controlled by varying the deposition time of carbonaceous (c) spheres from 4 to 16 h with the interval of 4 h, which affect the size of TiO2 spheres. The structural, morphological, optical, compositional and photoelectrochemical properties of the TiO2 thin films were studied. X-ray diffraction (XRD) pattern confirms the formation of anatase TiO2 with the tetragonal crystal structure. Field emission scanning electron microscopy analysis revealed that the synthesized anatase TiO2 microspheres has average diameter of similar to 330-510 nm. The blueshift in optical absorption is observed due to Mie scattering. The indirect optical band gap energy of TiO2 was varied over 3.05-3.16 eV, with the increase in deposition time. The HRTEM and SAED results show the polycrystalline nature of the sample which is in good agreement with the XRD. The anatase TiO2 hollow spheres with mesoporous walls and high specific surface area i.e. 41 m(2) g(-1) was obtained using this simple method. The films were photoelectrochemically active with maximum current density 531 mu A/cm(2) under 100 mW/cm(2) illuminations.</P>

Substantially enhanced front illumination photocurrent in porous SnO₂ nanorods/networked BiVO₄ heterojunction photoanodes

Bhat, Swetha S. M.,Suh, Jun Min,Choi, Seokhoon,Hong, Seung-Pyo,Lee, Sol A.,Kim, Changyeon,Moon, Cheon Woo,Lee, Mi Gyoung,Jang, Ho Won The Royal Society of Chemistry 2018 Journal of Materials Chemistry A Vol.6 No.30

<P>BiVO4 is a promising photoanode for photoelectrochemical applications owing to its suitable band edge position for oxygen evolving reactions. High photocurrent under front illumination is very much essential to design tandem structures with a wireless configuration. However, the performance of BiVO4 under front illumination is limited due to poor charge transport properties. Here, we show that network-like BiVO4 coupled with porous SnO2 nanorods (NRs) is a promising model to enhance the front illumination performance. A very high photocurrent density of 5.6 mA cm<SUP>−2</SUP> and 5.5 mA cm<SUP>−2</SUP> has been obtained from the front and back illumination at 1.23 V <I>vs.</I> the reversible hydrogen electrode, respectively. We demonstrate that the appropriate nanostructuring of SnO2 NRs/BiVO4 is the underlying technology to tune the performance under directional illumination. The SnO2 NRs/BiVO4 exhibits a maximum incident photon to current efficiency of ∼80% under front and back illumination. A systematic study reveals that the optimized network like BiVO4 coated on porous SnO2 NRs synergistically boosts both the charge separation and transfer efficiencies of the photoanode resulting in a significantly high photocurrent for illumination on either side. This work provides a direction to achieve enhanced photocurrent during front and back side illumination in order to realize a wireless tandem configuration.</P>

Recent Advances in Bismuth-Based Nanomaterials for Photoelectrochemical Water Splitting

Bhat, Swetha S. M.,Jang, Ho Won WILEY-VCH 2017 CHEM SUS CHEM Vol.10 No.15

<P>In recent years, bismuth-based nanomaterials have drawn considerable interest as potential candidates for photoelectro-chemical (PEC) water splitting owing to their narrow band gaps, nontoxicity, and low costs. The unique electronic structure of bismuth-based materials with a well-dispersed valence band comprising Bi6s and O2p orbitals offers a suitable band gap to harvest visible light. This Review presents significant advancements in exploiting bismuth-based nanomaterials for solar water splitting. An overview of the different strategies employed and the new ideas adopted to improve the PEC performance of bismuth-based nanomaterials are discussed. Morphology control, the construction of heterojunctions, doping, and co-catalyst loading are several approaches that are implemented to improve the efficiency of solar water splitting. Key issues are identified and guidelines are suggested to rationalize the design of efficient bismuth-based materials for sunlight-driven water splitting.</P>

Substantially enhanced photoelectrochemical performance of TiO₂ nanorods/CdS nanocrystals heterojunction photoanode decorated with MoS₂ nanosheets

Bhat, Swetha S.M.,Pawar, Sachin A.,Potphode, Darshna,Moon, Chang-Ki,Suh, Jun Min,Kim, Changyeon,Choi, Seokhoon,Patil, Dipali S.,Kim, Jang-Joo,Shin, Jae Cheol,Jang, Ho Won Elsevier 2019 Applied Catalysis B Vol.259 No.-

<P><B>Abstract</B></P> <P>Two-dimensional (2D) MoS<SUB>2</SUB> nanosheets (NSs) modified 1D TiO<SUB>2</SUB> nanorods/0D CdS nanocrystals (NCs) heterojunction has been fabricated by all solution process as a potential anode for photoelectrochemical (PEC) water splitting applications. This heterojunction photoanode shows high photocurrent density of 3.25 mA/cm<SUP>2</SUP> at 0.9 V vs. RHE (0 V vs. Ag/AgCl) compared to the pristine TiO<SUB>2</SUB>/CdS photoanode. The influence of MoS<SUB>2</SUB> NSs on PEC performance of TiO<SUB>2</SUB>/CdS/MoS<SUB>2</SUB> heterojunction has been systematically investigated. We demonstrate that MoS<SUB>2</SUB> NSs transfer holes from CdS and facilitate further charge separation in TiO<SUB>2</SUB>/CdS. Time resolved photoluminescence measurement reveals increase in photoluminescence lifetime due to the presence of MoS<SUB>2</SUB> NSs in TiO<SUB>2</SUB>/CdS/MoS<SUB>2</SUB> resulting in enhanced PEC activity. This work suggests that 1D TiO<SUB>2</SUB>/0D CdS/2D MoS<SUB>2</SUB> heterojunction prototype is an interesting system where MoS<SUB>2</SUB> NSs can be utilized to improve charge separation in photoanodes. This study would pave the way towards designing new heterojunction functional materials for efficient PEC applications.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Photoanodes were fabricated by all solution process. </LI> <LI> Enhanced photoelectrochemical performance of TiO<SUB>2</SUB> 1D/0D CdS/MoS<SUB>2</SUB> 2D triple heterojunction photoanode was achieved. </LI> <LI> The heterojunction photoanode shows high photocurrent density of 3.25 mA/cm<SUP>2</SUP> at 0.9 V vs. RHE (0 V vs. Ag/AgCl). </LI> <LI> Role of MoS<SUB>2</SUB> nanosheets on the improved photoelectrochemical performance has been investigated. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>Decoration of solution-processed MoS<SUB>2</SUB> nanosheets on TiO<SUB>2</SUB> nanorods/CdS nanocrystals photoanode substantially improves the photoelectrochemical performance. The heterojunction photoanode TiO<SUB>2</SUB>/CdS/MoS<SUB>2</SUB> with ZnS shows high photocurrent density of 3.25 mA/cm<SUP>2</SUP> at 0 V vs. Ag/AgCl (0.9 V vs. RHE).</P> <P>[DISPLAY OMISSION]</P>

Electron irradiation effects on electrical and optical properties of sol-gel prepared ZnO films

Bhat, J. S.,Patil, A. S.,Swami, N.,Mulimani, B. G.,Gayathri, B. R.,Deshpande, N. G.,Kim, G. H.,Seo, M. S.,Lee, Y. P. American Institute of Physics 2010 JOURNAL OF APPLIED PHYSICS - Vol.108 No.4

Marker-assisted selection for scab resistance and columnar growth habit in inter-varietal population of apple (Malus × domestica)

Rasool Aatifa,Bhat K. M.,Mir M. A.,Sundouri A. S.,ALshamrani Salha Mesfer,Aloufi Abeer S.,El Moneim Diaa Abd,Mansoor Sheikh,정용석 한국식물생명공학회 2024 Plant biotechnology reports Vol.18 No.1

In recent years, there has been significant progress in enhancing the genetic foundation underlying important agricultural traits such as resistance to scab and the development of a columnar growth habit. V. inaequalis is a hemibiotrophic fungus widely distributed in temperate regions where apples are grown on commercial scale. The present investigation was undertaken to identify Vf gene and Co gene, which, respectively, confer resistance against apple scab disease and columnar phenotype in apple cultivar ‘Rosalie’ and introgression of both the genes in commercially important cultivar ‘Fuji’. Polymorphism sur- vey was carried out between the two parents using 22 simple sequence repeat (SSR) and sequence-characterized amplified region (SCAR) markers. The observations revealed that almost 50% hybrids fall in resistant category and 50% in susceptible category. The results of marker-assisted screening confirmed 38 F1s carrying resistance gene for scab while the remain- ing 32 F1 plants were found to be lacking the gene. The 38 genotypically scab-resistant hybrids were selected for further characterization as columnar and non-columnar plants. Based on the selection criteria, 21 individuals were categorized as columnar and the remaining 17 were categorized as non-columnar. The phenotypic screening was followed by screening of F1 s using molecular markers for Co gene. The amplification of Co-specific markers yielded columnar-specific fragments in the population and fitted the expected 1:1 Mendelian ratio. 18 scab-resistant F1 hybrids were found to carry Co gene and the remaining 20 did not possess the gene for columnar growth habit. Gene-specific primers identified in the present study can be directly used for screening large apple germplasm in a short period of time for developing resistant varieties against apple scab as well as varieties with columnar growth habit. Hybrids with verified scab resistance and columnar growth can be swiftly utilized as scab-resistant columnar cultivars.

Acidophilic Tannase from Marine Aspergillus awamori BTMFW032

( BeeNa P. S. ),( M. B. Soorej ),( K. K. Elyas. ),( G. Bhat Sarta ),( M. Chandrasekaran ) 한국미생물 · 생명공학회 2010 Journal of microbiology and biotechnology Vol.20 No.10

Aspergillus awamori BTMFW032, isolated from sea water, produced tannase as an extracellular enzyme under submerged culture conditions. Enzymes with a specific activity of 2,761.89 IU/mg protein, a final yield of 0.51%, and a purification fold of 6.32 were obtained after purification through to homogeneity, by ultrafiltration and gel filtration. SDS-PAGE analyses, under nonreducing and reducing conditions, yielded a single band of 230 kDa and 37.8 kDa, respectively, indicating the presence of six identical monomers. A pI of 4.4 and a carbohydrate content of 8.02% were observed in the enzyme. The optimal temperature was found to be 30oC, although the enzyme was active in the range of 5-80oC. Two pH optima, pH 2 and pH 8, were recorded, although the enzyme was instable at a pH of 8, but stable at a pH of 2.0 for 24 h. Methylgallate recorded maximal affinity, and Km and Vmax were recorded at 1.9× 10-3M and 830 ?mol/min, respectively. The impacts of a number of metal salts, solvents, surfactants, and other typical enzyme inhibitors on tannase activity were determined in order to establish the novel characteristics of the enzyme. The gene encoding tannase, isolated from A. awamori, was found to be 1.232 kb, and nucleic acid sequence analysis revealed an open reading frame consisting of 1,122 bp (374 amino acids) of one stretch in the -1 strand. In silico analyses of gene sequences, and a comparison with reported sequences of other species of Aspergillus, indicate that the acidophilic tannase from marine A. awamori differs from that of other reported species.

Effect of porcine placenta steroid extract on myogenic satellite cell proliferation, transdifferentiation, and lipid accumulation

Lee, E. J.,Kamli, M. R.,Bhat, A. R.,Pokharel, S.,Lee, D. M.,Kim, S. H.,Kim, T. I.,Hong, S.,Choi, I. Springer Science + Business Media 2012 In vitro cellular & developmental biology. Animal Vol.48 No.5

Understanding corrosion inhibition of mild steel in acid medium by new benzonitriles: Insights from experimental and computational studies

Chaouiki, A.,Lgaz, H.,Chung, Ill-Min,Ali, I.H.,Gaonkar, S.L.,Bhat, K.S.,Salghi, R.,Oudda, H.,Khan, M.I. Elsevier 2018 Journal of molecular liquids Vol.266 No.-

<P><B>Abstract</B></P> <P>Two benzonitrile derivatives, namely 4-(isopentylamino)-3-nitrobenzonitrile (PANB) and 3-amino-4-(isopentylamino)benzonitrile(APAB) have been synthesized and evaluated as corrosion inhibitors for mild steel (MS) in 1 M HCl solution at 303 K by gravimetric, potentiodynamic polarization (PDP) curves, and electrochemical impedance spectroscopy (EIS) methods, as well as Density Functional Theory (DFT) and molecular dynamics (MD) simulations. The results suggest that tested compounds are excellent corrosion inhibitors for mild steel with PANB showing superior performance. Polarization measurements revealed that PANB and APAB behaved as mixed type inhibitors. The polarization resistance, according to EIS studies, found to be dependent on the inhibitor's concentration. The adsorption of PANB and APAB on mild steel surface obeyed Langmuir's adsorption isotherm. On the one hand, DFT and MD simulations are being used to explain the effect of the molecular structure on the corrosion inhibition efficiency and on the other hand to simulate the adsorption of benzonitrile derivatives on mild steel surface. The protection of carbon steel in 1 M HCl was confirmed by using scanning electron microscope (SEM) and Atomic Force Microscopy (AFM). Electrochemical, DFT and MD simulations results are in good agreement.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Novel benzonitrile derivatives have been synthesized and characterized. </LI> <LI> Potentiodynamic polarization curves reveal that tested inhibitors act as mixed type. </LI> <LI> The adsorption of two compounds obeys Langmuir adsorption isotherm. </LI> <LI> Surface morphology was examined by SEM and AFM. </LI> <LI> The experimental results were correlated with DFT and MD stimulation results. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

A Comparison of Three-Phase High-Frequency Transformer Isolated LCC and LCL-Type DC-DC Resonant Converter Topologies

M. Almardy,A.K.S. Bhat 전력전자학회 2015 ICPE(ISPE)논문집 Vol.2015 No.6

A comparison of HF transformer isolated, softs-witched 3-phase LCC-type and (LC)(L)-type dc-dc resonant converters with capacitive output filters including the effect of the HF transformer magnetizing inductances are presented. These converters are designed for the same specifications based on the approximate analysis approach. Intusoft simulation results for both designed converters are given for various input voltage and for different load conditions. The experimental verification of the designed converters performance are established by building a 300W rated power converters in the power electronics lab and the experimental results for both converters have been given. A variable frequency control with 180<SUP>0</SUP> wide gating pulses is adopted for regulating the output. Both converters operate in zero-voltage switching (ZVS) at various input voltage and different load conditions.