Advanced Carbon-based Materials for Green Energy Generation and Storage: Experimental and First Principle Studies

by Zhemi Xu

Institution: University of New South Wales
Department: Materials Science & Engineering
Year: 0
Keywords: Supercapacitor; Graphene; Porous carbon; Water splitting
Record ID: 1053839
Full text PDF: http://handle.unsw.edu.au/1959.4/53580


Recently, advanced Carbon based materials have shown potential capabilities in clean energy conversion and storage. In this work, we focus on the studies: (a) Water dissociation and adsorption on graphene under UV Irradiation and (b) electrochemical behaviour of carbon foam-metal oxide nanosheet composites. The current study aims to understand the mechanism of light-driven water splitting and future high performance supercapacitor design, respectively. Firstly, water splitting on graphene under UV light has been studied by experimental and theoretical approaches. The results indicate that under UV irradiation, H2O molecules dissociate into hydrogen and hydroxyl radicals, and then were captured on the graphene surface. The research may give a fundamental understanding of physical and chemical properties of graphene, thus providing a facile and cost-effective approach for water splitting. Secondly, from energy storage aspect, high performance carbon foam based supercapacitors were studied by combining porous carbon foams and metal oxides. In this work, Co3O4 nanosheets/carbon foam was successfully fabricated via a one-step electrodeposition method, which has good supercapacitor characteristics. And then, by introducing doping method, Gd-doped CeOx nanoflowers on porous carbon with excellent supercapacitor performance was synthesized, followed with an UV (ultraviolet) irradiation. Through the combination of porous carbon and metal oxides, supercapacitors with highly stable, long cycle life, excellent energy storage performance, were successfully achieved. In addition, the capacitance of metal oxide thin films achieved a further improvement by doping heteroatom, which opens a gap in applying doping methods in supercapacitors synthesis to enhance the performance. In summary, this work systematically explored the mechanism of water splitting on graphene films under UV irradiation and improved the carbon foam based metal oxides supercapacitor.