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Dr. C. Kavitha

Department of Physics, Centre for Advanced Materials Research, BMS Institute of Technology & Management,

Affiliated to Viveshwaraya Technological, University, Karnataka, India

 

Talk Title
Reduced Graphene Oxide/Metal Oxide hybrid nano structures for supercapacitative and Surface Enhanced Raman Spectroscopy applications

Talk Abstract

Electrochemical supercapacitors store significantly more energy than conventional capacitors but less than that of batteries, and their construction is similar to that of conventional capacitors except that the metal electrodes are replaced by a highly porous electrode. The dielectric film separating the two electrodes is porous, and the cell contains a suitable electrolyte such as aqueous H2SO4. Energy is stored in supercapacitors through the formation of an electrical double layer at the interface of the electrode (electrical double layer capacitors, EDLCs) or due to electron transfer between the electrolyte and the electrode through fast Faradiac redox reactions (pseudocapacitors).  For capacitors, the energy stored is inversely proportional to the thickness of the double layer, and therefore these capacitors have an extremely high energy density compared to conventional dielectric capacitors. High power capacity, long life, broad thermal operating range, low weight, flexible packaging and low maintenance are some of the other advantages of supercapacitors. In addition to the high surface area, graphene based materials offer high electrical conductivity that enables rapid electrical charge transfer from one electrode to the other. Consequently, much interest in recent years has focused on graphene as electrode material in supercapacitors with the aim of achieving high specific capacity and power density. The effective surface area and conductivity of a graphene film depends strongly on growth conditions and the number of layers without agglomeration.   Functional materials based on reduced graphene oxide (rGO) and metal oxide nanoparticles possess superior properties arising from the synergy of the individual properties. Obtaining these materials in the form of large area films are advantageous for most applications involving sensing, photovoltaics, supercapacitors etc. We have synthesized free standing, thin films of rGO with semiconductor nanostructures such as ZnO, CuO, SnO2 and magnetic nanoparticles such as Fe2O3 at a liquid/liquid interface employing a simple interfacial reaction of the precursors. The method can be adopted as a general route to prepare rGO based metal oxide films. rGO-ZnO films consist of hexagonal cylinders of ZnO and rGO-Fe2O3 films exhibit particle or rod-like morphologies of iron oxide interspersed with rGO layers. The applications of these hybrid films as renewable surface enhanced Raman substrates (SERS) and supercapacitors are demonstrated. The higher photodegradation rates provided by the metal oxide-rGO hybrids enable regeneration of the used SERS substrate while the contribution from electric double layer capacitance of rGO and pseudocapacitance due to metal oxide enhances the charge storage in hybrids.

Short Biography

This is Dr. C. Kavitha working as a Assistant professor in Department of Physics, Centre for Advanced Materials Research, BMSIT&M, Bangalore.  I have completed my regular Ph.D in materials Science in JNCASR, bangalore during 2002-2008. I have done one Post doctoral work in Raman Research Institute (RRI) during (2009-2011) and another postdoctral work in IPC Department, Indian Institute of Science (IISc), Bangalore during (2011-2013). In 2014, I have received DST-SERB young Scientist award worth Rs. 32 Lakhs to set up Advanced Materials Research lab in BMSIT&M, Bangalore. The project is completed successfully. Recently selected for VGST-Seed money for young faculty, Karnataka Government (2018-2020).   I have started my Ph.D research work at JNCASR on two optical probes, namely, Raman and Brillouin spectroscopy to study the physical properties of the materials.  At RRI, I have studied the enhanced photoconductivity of gold chloride doped hexa alkoxy triphenylene series (HAT4, HAT5 and HAT6). The high NIR absorbance combined with the photoconductivity makes this nanocomposite a potential candidate for organic solar cell applications.  Recently we have employed low cost rGO-Ag hybrid thin-films for SERS based dye sensor and working on graphene based supercapacitor materials.

 
Talk Keywords
 Reduced graphene oxide; metal oxides; hybrid nanostructure; SERS; Supercapacitor.
 
Target Audience
Students, Post doctoral, Industry, Doctors and professors
 
Speaker-intro video
TBA 
 

The International Conference on Innovative Applied Energy (IAPE’18)