New materials for photocatalysis and photovoltaics

QD Chemistry

Lafta, Abbas Jassim Attia ; Hargreaves, Justin

University:University of Glasgow

Department:School of Chemistry

关键词: Photocatalysis, photovoltaics, titanium dioxide, doping nitrogen over titanium dioxide, electrochemical polymerization;   

Others  :  http://theses.gla.ac.uk/4105/1/2013LaftaPh.D..pdf

来源: University of Glasgow

【 摘 要 】

Photocatalytic processes are of widespread interest. Among different types ofphotocatalytic material TiO2 is the generally considered amongst the best due to itsfavourable physical and chemical properties. In recent decades, photovoltaic devices havebeen widely studied to provide alternative routes to energy and reduce dependency uponfossil fuel. Solar photovoltaic are cells capable of harvesting of sunlight into electricalpower. This technology is one of the most promising routes in the search for sustainableand renewable sources of energy. The study presented in this thesis relates to thepreparation and characterization of a range of different materials which can be applied inphotocatalytic processes and for photovoltaic devices.The photocatalysis work has been focused mainly upon modification of the various phasesof titanium dioxide. This has been undertaken via doping with nitrogen by treatment withammonia at different temperatures. In addition, samples containing Al, Co and Cu dopants,as well as their N doped counterparts, have been prepared, characterized and tested. Thephotocatalytic activity was screened by following photocatalytic decomposition of anaqueous solution of methylene blue using a light source containing various components inthe UV and visible regions. For selected samples, the photocatalytic activity forpolymerization of methyl methacrylate and styrene has been determined with the aim ofproducing composites.In terms of potential photovoltaic materials, the synthesis of novel viologen compoundsand polymerization via electrochemical and chemical means has been undertaken.Different viologen monomers have been synthesized with various moieties in conjugationto a phenanthroline core to afford novel push-pull systems. These compounds haveincorporated both TCNE and TCNQ moieties as strong electron acceptors and hence yieldchromophore with large dipole moments. In addition, novel ruthenium complexes wereprepared featuring bipyridine and phenanthroline ligands. The optical and redox propertiesof these materials have been investigated. DSSCs have been fabricated form some of thesesystems and their properties have been compared to dye 719.