Vellore Institute of Technology (VIT) is a private university located in&nbsp;Tamil Nadu, India. Founded in 1984, as Vellore Engineering College, the institution offers 20 undergraduate, 34 postgraduate, four integrated and four research programs. It has campuses in Vellore, Amravati, Bhopal and Chennai.

VIT is one of the top ranked private universities in India according to NIRF, THE and QS Rankings.&nbsp;Govt. of India has recognized&nbsp;VIT, Vellore as an&nbsp;Institution of Eminence. This has allowed VIT to take independent quality initiatives and move up in world ranking.

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VIT University

Department of Physics

This article reports the effect of pure CeO2 and Cu (1%, 3% and 5 mol %) doped CeO2 Nanoparticles (NPs) have been prepared by very simple and improved co-precipitation method. Synthesized NPs has been subjected to several analytical methods, viz. XRD, TEM and UV-Vis spectral analysis. XRD data analysis confirmed that face cubic structure and average size are found to be in the range 5-10nm. Particle size and morphological studies as observed from TEM exhibits almost identical cubical shaped particles with average size 5-8nm. The tuning of band gap energy has been observed from UV-Visible absorption spectrum of cerium oxide NPs upon Cu (1%, 3%, and 5mol %) incorporation. Degradation of the methylene blue (MB) through photocatalysis has been observed for pure and Cu (1%, 3% and 5 mol%) CeO2 nanoparticles under solar spectrum. In addition, pure and Cu (1%, 3% and 5 mol %) cerium oxide nanoparticles has also been subjected to antibacterial response using different strains. © 2020 by the authors.

World University root node

School of Advanced Sciences

Vellore Campus

Biointerface Research in Applied Chemistry

Synthesis and characterization of pure and CU doped CEO2 nanoparticles: Photocatalytic and antibacterial activities evaluation

Hydrogen production using novel catalysts is regarded as one of the most needed technology for the future economic needs and water splitting to give H2 gas, which is a challenging task for large-scale production. This work reports the synthesis of Meso-Cu-BTC metal organic framework and further used for understanding its role in electrochemical hydrogen evolution reaction (HER) in 1 M NaOH solution. Meso-Cu-BTC electrocatalyst showed a less overpotential of 89.32 mV and an onset potential of 25 mV with an appreciable current density. Results show a low Tafel slope of 33.41 mVdec-1 and long-term durability. Thus, the overall results show that Meso-Cu-BTC acted as a good candidate for electrocatalysis towards hydrogen evolution. © 2020 The Author(s). Published by IOP Publishing Ltd.

Centre for Nanotechnology Research

Department of Bio-Medical Sciences

School of Bio Sciences and Technology

Fulltext

Materials Research Express

Cu based Metal Organic Framework (Cu-MOF) for electrocatalytic hydrogen evolution reaction

Understanding the radiation dose enhancement factor (DEF) influencing parameter and relevant radiological properties is important for the accurate estimation of absorbed dose in nanoparticle enhanced X-ray therapy (NEXT). In this present study, target tumor tissue influence on DEF produced by 18 mg/g gold nanoparticle (GNP) in ten various biological samples and relevant radiological properties were studied over 15KeV-15MeV energies. The DEF was calculated with the help of mass energy-absorption coefficients (μen/ρ) values. Mass attenuation coefficient (μ/ρ), (μen/ρ), photoelectric absorption coefficients were computed with the help of the XCOM program. Energy absorption buildup factor (EABF), exposure buildup factor (EBF) and effective atomic number (Zeff) were calculated by EXABCAL and auto Zeff computer program respectively. DEF were significantly varied according to target biological tissue elemental composition and incident photon energies. Among the ten various biological samples, adipose tissue target produces higher DEF which have the lower Zeff and bone produce lower DEF which possess higher Zeff. Optimal energy for the maximum DEF is 40 KeV and 100 KeV for soft tissues and bone respectively. EABF and EBF of GNP doped tissues were discussed as the function of energy and elemental composition and mean free path up 40 mfp. Energy and inhomogeneity correction factors are necessary for the accurate estimation of DEF. These results are helpful for developing the treatment planning algorithms and dosimetry for NEXT. Age and calcification dependent variation of the elemental composition of the target tissue and its effect on DEF need to account for the future work.

Radiation Physics and Chemistry

Target biological tissue and energy influence on dose enhancement factor produced by gold nanoparticles and its relevant radiological properties

Journal of Crystal Growth

Colossal dielectric behaviour of Sr2TiMnO6-δ single crystals

Single crystals of Sm0.55Sr0.45Mn0.4Fe0.6O3 were grown by an optical floating zone technique in an oxygen atmosphere. The powder X-ray diffraction pattern for the grown crystal revealed single-crystalline nature. The lattice parameters and atomic structure were refined and indexed using a General Structure Analysis System (GSAS) to an orthorhombic structure with lattice parameters a = 5.4415 (32) Å, b = 7.6994 (27) Å, c = 5.43868 (28) Å, and space group Pnma. © International Centre for Diffraction Data 2020.

Powder Diffraction

Rietveld refinement of Sm0.55Sr0.45Mn0.4Fe0.6O3

The development of low-cost and high-performance oxygen reduction reaction (ORR) catalysts is important for renewable energy storage and conversion systems, such as fuel cell. Herein, we report a simple and facile surface engineering strategy for nickel and cobalt based (NiO–Co3O4) hybrid as efficient and robust ORR electrocatalyst. The surface nanostructure of NiO–Co3O4 nanohybrids can be easily tuned by controlling the precursor amounts of nickel and cobalt during a wet-chemical synthesis. With an optimal composition, an intriguing surface structure consisted of one dimensional (1D) nanorod with two dimensional (2D) nanosheet can be obtained for NiO–Co3O4 nanohybrids, which significantly boosts ORR electrocatalytic activity as well as stability. A facile charge or mass transfer within 1D and 2D open surface nanostructures is mainly responsible for an excellent catalytic performance of NiO–Co3O4 nanohybrids. © 2020 Elsevier Ltd and Techna Group S.r.l.

Ceramics International

Surface engineered NiO–Co3O4 nanostructures as high-performance electrocatalysts for oxygen reduction reaction

The development of efficient, low-cost, and stable bifunctional catalysts is necessary for renewable energy storage and conversion, but it remains a challenge. Herein, we first report a novel strategy to develop WO3·nH2O (n = 0.33, 1.00, or 2.00) as a highly active and durable bifunctional catalyst for the oxygen reduction reaction (ORR) and hydrogen evolution reaction (HER) in acidic media by controlling the degree of hydration. The content of solvated water molecules in WO3·nH2O can be precisely controlled by selectively using ethylenediaminetetraacetic acid or dl-malic acid for room-temperature precipitation synthesis. Structural flexibility associated with water solvation in WO3·nH2O leads to excellent bifunctional catalytic activity as well as durability in acidic media. The bifunctional catalytic mechanism of WO3·nH2O is mainly attributed to spontaneous partial dehydration during electrolysis, resulting in simultaneous formation of active phases for HER and ORR, respectively. Copyright © 2020 American Chemical Society.

ACS Sustainable Chemistry and Engineering

Partial Dehydration in Hydrated Tungsten Oxide Nanoplates Leads to Excellent and Robust Bifunctional Oxygen Reduction and Hydrogen Evolution Reactions in Acidic Media

Resistance to antibiotics is a global concern and urgently needs sincere attention. Looking toward the current scenario there is a definite need for hybrid systems which can combat with the pathogens. One such approach is synthesis of CuO NPs using cow urine for the first time. The advantage of this method is its eco-friendly and economical synthesis approach. It is seen that the prepared NPs exhibit excellent antimicrobial activity against test microorganism such as Staphylococcus aureus, Klebsiella pneumoniae, and Pseudomonas aeruginosa. Also, the synthesized NPs show synergistic effectiveness with common broad spectrum antibiotic tetracycline. In addition, the prepared NPs are also tested for anticancer activity by using MTT assay and results suggests that the prepared NPs shows excellent anticancer activity against MCF7 cell lines. The developed material carries excellent potential in biomedical application. © 2020 Wiley-VCH GmbH

Macromolecular Symposia

Bos taurus Urine Assisted Biosynthesis of CuO Nanomaterials: A New Paradigm of Antimicrobial and Antineoplatic Therapy

Energy storage devices based on the two-dimensional transition metal dichalcogenides (TMDs) have great interest due to their fascinating physical and chemical properties. In this study, Mn incorporated MoS2 nanosheets are self-assembled into nanoflowers via a simple one-step hydrothermal process. The nanoflowers retain the feature of the high specific surface area of the nanosheets and the intercalation of Mn atoms up to a certain amount increases the porosity of MoS2, thus enhancing active sites for reaction. The presence of an intermediate oxidation state of Mn (Mn3+), which also plays an important role in increasing capacitance, is highest in low doped sample resulting in superior capacitance performance compared to bare and high Mn content samples. So the supercapacitor electrode made of low Mn incorporated MoS2 nanoflowers exhibits maximum specific capacitance (430 F g−1), energy density 48.9 W h kg−1 and power density 5.0 kW kg−1 with excellent capacitance retention up to 5000 cycles at 10 A g−1, when used as a supercapacitor electrode. Further, the performance of the electrode material has been examined by lightning four LED bulbs in series showing longer discharge time. Our findings open new areas to explore Mn doping with TMDs as next-generation energy devices systematically. © 2020 Elsevier Ltd

Electrochimica Acta

Mn incorporated MoS2 nanoflowers: A high performance electrode material for symmetric supercapacitor

AM80 magnesium alloy was processed by Equal Channel Angular Pressing up to 2 passes under route BC and C, to study the effect of change in microstructure. Microstructures were examined under optical microscope. Samples processed by route BC showed heterogeneous grain structure with good tensile strength compared to that processed by route C. Tensile tests of 2-pass equal channel angular pressed samples showed high tensile strength under route BC. Laser shock peening without coating was carried out on route BC sample for further grain refinement on the surface. Laser pulses with power density of 8 GW cm−2, under different percentages of cover, were used to peen the surface at high strain rate. Microstructures were analysed through scanning and transmission electron microscope, and fine grains of less than 100 nm were observed. Tensile tests indicated that the laser shock peened samples had increased strength and ductility. Fracture details from tensile tested specimens, were examined under SEM. Mixed mode of brittle and ductile fractures was observed in ECAP processed samples. Fracture surface of Laser shock peening without coating treated on equal channel angular pressed samples showed small dimples near the peened surface and intensity of dimples increased with increase in percentage of cover. Wear test was carried out on before and after Laser shock peening without coating processed samples, on pin-on-disc wear test machine. Increase in friction coefficients and wear rate was observed due to roughness induced by peening effect and it decreased after increase in sliding distance due to increase in hardness. Nano indentation experiments were carried out to examine the mechanical characterization at nano level, and it expose the effect of LSPwC in terms of increase in hardness at peened region. © 2020