Nanoengineered Carbon Metal Oxide Based Electrochemical Supercapacitors

Abstract

To address this issue, the thesis represents four major strategies to synthesize proper electrode newlinematerials ranging from 3D nanocrystalline diamond to 1D diamond nanostructure to newlinepseudocapacitive transition metal oxide thin films. My thesis work started with the newlinemicrofabrication of conductive boron-doped hybrid carbon nanowalls (HCNWs), where sp2 newline- newlinebonded graphene has been integrated with and over a three-dimensional curved wall-like newlinenetwork of sp3 newline-bonded diamond. The second part of my thesis focuses on the synthesis of a newlinenanostructured carbon hybrid consisting of vertically aligned 1D carbon nanograss on top of newline3D boron-doped nanocrystalline diamond. In the third part of my thesis, a simple single-step newlinesynthesis of core-shell diamond-graphite hybrid electrodes are demonstrated by a mere newlinevariation CH4 concentration (CC) in the microwave growth plasma. Finally, room temperature newlinetransformation from anatase TiO2 (A-TiO2) to rutile-TiO2 (R-TiO2) thin films driven by a newlinecontrolled oxygen flow rate is investigated. These TiO2 films are deposited on top of boron newlinedoped diamond (BDD) to make BDD/TiO2 hybrid structures. In the application scenario, all newlinethe prepared carbon/carbon and carbon/metal oxide hybrids are applied as electrode material newlinefor the fabrication of EC supercapacitor. To explain the supercapacitor performance of these newlineelectrodes, in-depth structural, electrical, and EC investigations are carried out to find out the newlinerole of dopants, non-diamond phases and dual advantage of sp2 newlineand sp3 newlinebonded carbon in the newlinehybrid structure.