Faculty Publications
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Item ZnO/carbon nanotube nanocomposite for high energy density supercapacitors(2013) Aravinda, L.S.; Nagaraja, K.K.; Nagaraja, H.S.; Bhat, K.; Badekai Ramachandra, B.A facile, green and highly efficient method for the decoration of carbon nanotubes with ZnO was developed for the fabrication of binder-free composite electrode for supercapacitor applications. The nano composite was prepared by using reactive magnetron sputtering in Ar/O2 environment. This approach leads to more uniform coating with tuneable thickness, which alters the electrochemical performance of the nano composite electrodes. The structure and surface morphology of the composite film have been studied by means of X-ray diffraction (XRD) analysis, scanning electron microscopy and field emission scanning electron microscopy (FESEM). The XRD study reveals the formation of Wurtzite ZnO structure. The electrochemical performance of nano composite electrode was investigated using cyclic voltammetry, chronopotentiometry and electrochemical impedance measurements in non-aqueous electrolyte. The nano composite electrode shows significant increase in the specific capacitance up to 48 F g-1 with an energy density 13.1 Wh kg-1 in the potential range -2 V to 1 V. © 2013 Elsevier Ltd. All rights reserved.Item Aluminising of mild steel using Al-11Si-1.2Cu baths(2013) Shashibhushan Raju, M.; Prashanth, H.; Bhat, K.Hot-dip aluminising of mild steel was done using Al-11Si-1.2Cu (at %) bath at 750°C for dipping time ranging from 300 to 3600 seconds. Aluminised layer was investigated using scanning electron microscope and energy dispersive spectroscopy. The intermetallic layer consisted of 4 distinct layers, namely, ?5-(Al7Fe2Si), ?-FeAl3, ?-Fe2Al5 and ?1-(Al,Si)5Fe3. Total intermetallic layer thickness was following parabolic growth kinetics with time. Total thickness was increasing predominantly due to increase in Fe2Al5 layer, which itself was following parabolic growth behaviour. Total intermetallic layer thickness was smaller compared to intermetallic layer thickness reported using pure aluminium or aluminium silicon baths. © 2013 CAFET-INNOVA TECHNICAL SOCIETY.Item Effect of substrate temperature on the characteristics of ZnO films produced by a combination of thermal vapor deposition and oxidation processes(Springer New York LLC barbara.b.bertram@gsk.com, 2017) Sneha, C.; Prabukumar, C.; Jayalakshmi, M.; Bhat, S.; Bhat, K.In the present work, ZnO semiconductor films were prepared by following two step processes, namely, thermal vapor deposition of the zinc on the glass substrate followed by oxidative annealing. Substrate temperature during deposition of the zinc was varied. Structural properties and morphology of the ZnO films were investigated by using X-ray diffraction and scanning electron microscopy techniques. Hydrophobic nature of the film was confirmed by using contact angle analyser. Hall measurements facilitated the estimation of the carrier concentration, their mobility and their effect on the conductivity. Photoluminescence spectroscopy was used to analyse the lattice defect concentration in the film. Further, the sensor response of the ZnO film to CO gas was analysed. Sensor fabricated with ZnO films which were prepared by oxidizing Zn films deposited at higher substrate temperature were found to possess better response and faster response-recovery time than the film prepared using lower substrate temperature for zinc deposition. © 2017, Springer Science+Business Media, LLC.