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

Centre for Nanotechnology Research

Water pollution by various toxic contaminants has become one of the most serious problems worldwide. Various technologies have been used to treat water and waste water including chemical precipitation, ion-exchange, adsorption, membrane filtration, coagulation–flocculation, flotation and electrochemical methods. From past few decades, nanotechnology has gained wide attention and various nanomaterials have been developed for the water remediation. In the present review article, various nanomaterials have been reviewed which have been used for water decontamination. The special emphasis in the review has been given on adsorption, photocatalytic and antibacterial activity of nanomaterials.

World University root node

Vellore Campus

Chemical Engineering Journal

Role of nanomaterials in water treatment applications: A review

Tin oxide/graphene (SnO2/G) nanocomposites were prepared by a simple wet chemical route and the as prepared nanocomposites were characterized by X-ray diffraction (XRD), High Resolution Transmission Electron Microscopy (HRTEM) and Fourier transform infrared spectra (FTIR). The characterized results showed the tetragonal structure of SnO2 nanostructures on uniform distribution on graphene sheets with a particle size of ∼50 nm. The reduction of graphene oxide to graphene during SnO2/G synthesis was confirmed from FTIR analysis. HRTEM analysis showed that the individual SnO2 nanoparticles deposited on graphene sheets. The electrochemical performances of SnO2/G nanocomposites towards supercapacitors were studied in 6M KOH electrolyte. A maximum specific capacitance of 818.6 F/g was obtained for SnO2/G-a composite at 5 mV/s scan rate suggesting that the presence of graphene matrix in SnO2 nanoparticles have enhanced the electrochemical behaviour of SnO2. The galvanostatic charge/discharge studies confirmed the good cyclic stability of the composite electrode. These excellent electrochemical properties suggested that the SnO2/G nanocomposites could be used for high energy density supercapacitor electrode materials. © 2016

VIT Unitversity

Materials Research Bulletin

Synthesis of tin oxide/graphene (SnO 2 /G) nanocomposite and its electrochemical properties for supercapacitor applications

Pharmaceutical industries spend more money in developing new and efficient methods for delivering successful drugs for anticancer therapy. Electrospun nanofibers and nanoparticles loaded with drugs have versatile biomedical applications ranging from wound healing to anticancer therapy. We aimed to attempt for fabricating elastomeric poly (L-lactic acid-co-ε-caprolactone) (PLACL) with Aloe Vera (AV), magnesium oxide (MgO) nanoparticles, curcumin (CUR) and β-cyclodextrin (β-CD) composite nanofibers to control the growth of MCF-7 cells for breast cancer therapy. The study focused on the interaction of MgO nanoparticle with CUR and β-CD inhibiting the proliferation of Michigan Cancer Foundation-7 (MCF-7) breast cancer cells. FESEM micrographs of fabricated electrospun PLACL, PLACL/AV, PLACL/AV/MgO, PLACL/AV/MgO/CUR and PLACL/AV/MgO/β-CD nanofibrous scaffolds achieved bead free, random and uniform nanofibers with fiber diameter in the range of 786 ± 286, 507 ± 171, 334 ± 95, 360 ± 94 and 326 ± 80 nm respectively. Proliferation of MCF-7 cells was decreased by 65.92% in PLACL/AV/MgO/CUR with respect to PLACL/AV/MgO nanofibrous scaffolds on day 9. The obtained results proved that 1% CUR interacting with MgO nanoparticles showed higher inhibition of MCF-7 cells among all other nanofibrous scaffolds thus serving as a promising biocomposite material system for the breast cancer therapy. © 2016 Elsevier B.V.

Materials Science and Engineering: C

Sequel of MgO nanoparticles in PLACL nanofibers for anti-cancer therapy in synergy with curcumin/β-cyclodextrin

Fulltext

Bulletin of Materials Science

Bandgap engineered graphene and hexagonal boron nitride for resonant tunnelling diode

The surface conductivity of metal oxide based gas sensors are influenced by the composition of gases or gas/air mixture in the gas sensing environment. Native metal oxide based gas sensors like SnO2, ZnO and TiO2 have been exploited in the recent past to study their sensing abilities and selectivity towards various gases. The research carried in the recent years are aimed at adding variety of dopants mostly metal based dopants with the metal oxide semiconductor based gas sensors. The sensing mechanism involves small quantities of reducing or oxidizing gases interacting with the metal oxide sensing layer by means of chemisorption or physisorption. The sensing mechanism depends on reversible adsorption or desorption processes of the gas at semiconductor surfaces. The sensing layers are tailored made to be selective towards different gases by selecting dopants, optimal sensor temperatures, catalysts, synthesis and film fabrication techniques. Metals are doped in metal oxide primarily to enhance their conducting ability for a particular level of gas sample there by increasing the sensitivity of the metal oxide gas sensor. More over the doping also increases the selectivity of the metal oxide gas sensors towards a particular gas. The process of doping mostly involves replacing a metal atom in the crystal lattice of the metal oxide with the dopant. This leads to the change in the sensing layer resistance by several orders of magnitude. The review aims at exploring the dopants added to metal oxide semiconductor materials which can be used to sense variety of gases.

School of Electronics Engineering

Chennai Campus

Sensor Letters

Metal/Metal Oxide Doped Semiconductor Based Metal Oxide Gas Sensors—A Review

We design various tapered photonic crystal fibers (PCFs) , namely, hexagonal tapered PCF (H-TPCF), octagonal tapered PCF (O-TPCF) and decagonal tapered PCF (D-TPCF) for generating self-similar ultrashort pulses (USPs) and stretched pulses . Here, we report on pulse compression as well as pulse stretching using the above mentioned PCFs wherein both dispersion and nonlinear profiles vary exponentially. Of these PCFs, we use dispersion decreasing PCFs for pulse compression process and dispersion increasing PCFs for pulse stretching process. From the detailed analysis, we find that H-TPCFs could generate high quality USPs with more compression percentage whereas D-TPCFs could produce high quality stretched pulses with more stretching percentage.

Department of Physics

School of Advanced Sciences

Department of Instrumentation

School of Electrical Engineering

Laser Physics

All-normal dispersion passively mode-locked Yb-doped fiber laser using MoS2–PVA saturable absorber

In this work, primary (MEA), secondary (DEA) and tertiary (MDEA) alkanolamine absorbents with a synthesized zinc-metal complex functioning as a carbonic anhydrase (CA) mimetic catalyst were applied to the absorption-desorption of carbon dioxide. Regeneration of carbon dioxide was evaluated by using a semi-batch system and the formation and extinction of bicarbonate and carbamate species were analyzed by FTIR and 13C NMR spectroscopy. The zinc-metal complex can cause the rapid conversion from bicarbonate to carbon dioxide, confirming that the regeneration rate could be increased substantially. © 2015 The Korean Society of Industrial and Engineering Chemistry.

Journal of Industrial and Engineering Chemistry

Influences of zinc–metal complex on the carbon dioxide regeneration behaviors of alkanolamine absorbents

Extracellular biosynthesis of silver nanoparticles (AgNPs) has been investigated by screening the cell free supernatant of five marine bacterial isolates. Among the screened isolates, cell free supernatant of Microbacterium sp. NV4 mediated effective synthesis of AgNPs. The synthesized nanoparticles were characterized using UV-vis spectroscopy (UV), X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), and Transmission Electron Microscopy (TEM). The UV spectral analysis exhibited a peak at 420 nm confirming the synthesis of AgNPs. The face centered cubic structure and the average particle size (17-26 nm) of the biosynthesized AgNPs were confirmed by XRD and TEM analysis, respectively. FTIR spectrum showed the involvement of biomolecules in the formation of AgNPs. Further, biosynthesis of AgNPs was optimized using Response Surface Methodology (RSM) based on three-level Box-Behnken Design (BBD) in order to enhance the synthesis of AgNPs. The optimum synthesis was observed at pH 7, temperature 45 °C, and incubation time of 72 h. The biosynthesized AgNPs were applied for the photocatalytic degradation of the dye methylene blue under visible light irradiation. The electrons excited on exposure to light are accepted by the dissolved oxygen present in the reaction medium and converted to oxygen anion radicals. These radicals might cause the degradation of the dye into simpler molecules. The result obtained reveals that the synthesized AgNPs could effectively degrade the dye (92.2%) after 8 h of incubation. © 2015 Elsevier B.V.

Department of Bio-Medical Sciences

School of Bio Sciences and Technology

Ecological Engineering

Optimization of process parameters for the microbial synthesis of silver nanoparticles using 3-level Box–Behnken Design

Nanofluids are nanoscale colloidal suspensions containing condensed nanomaterials. Nanofluids have been found to possess enhanced thermos-physical properties such as thermal conductivity, thermal diffusivity, viscosity, and convective heat transfer coefficients compared to those of base fluids like oil or water. Boron Nitride (BN) nanoparticles - due to its high thermal conductivity, appropriate thermal expansion coefficient, high electrical insulation and high mechanical strength is a promising additive in traditional heat exchange fluids. In this work we synthesised Boron Nitride (BN) nanoparticles by hydrothermal method and the nanoparticles are characterized by XRD, EDAX and SEM. Nanofluids were prepared by different weight fractions of the nanoparticles in different ratio of water and Ethylene Glycol (EG) solution. Physiothermal properties of the fluids at different temperatures were investigated and the same is reported.

Indian Journal of Science and Technology

Synthesis and Physiothermal Analysis of Boron Nitride Based Nanofluid

Ultrashort pulsed laser is an indispensable tool for the evolution of photonic technology in the present and future. This laser has been progressing tremendously with new pulse regimes and incorporating novel devices inside its cavity. Recently, a nanomaterial based saturable absorber (SA) was used in ultrafast laser that has improved the lasing performance and caused a reduction in the physical dimension when compared to conventional SAs. To date, the nanomaterials that are exploited for the development of SA devices are carbon nanotubes, graphene, topological insulators, transition metal dichalcogenides (TMDs) and black phosphorous. These materials have unique advantages such as high nonlinear optical response, fiber compatibility and ease of fabrication. In these, TMDs are prominent and an emerging two-dimensional nanomaterial for photonics and optoelectronics applications. Therefore, we review the reports of Q-switched and mode-locked pulsed lasers using TMDs (specifically MoS2, MoSe2, WS2 and WSe2) based SAs. © 2016 Elsevier B.V.