Photoelectrochemical and photocatalytic production of solar fuels

Abstract

Solar Fuels is an expanding area of research in energy storage, with the likes of hydrogen, ammonia and methanol all being produced photocatalytically and photoelectrochemically, effectively storing solar energy as chemical energy. Ammonia is currently being investigated as a possible energy vector as a combustion fuel, hydrogen storage chemical and use in a fuel cell. However current synthesis methods lead to high emissions and energy consumption and are therefore not ideal. Utilisation of solar ammonia production techniques such as photocatalysis and photoelectrochemistry provide more environmentally friendly routes to ammonia synthesis, at ambient temperature and pressure. This research intends to investigate various semiconductor materials for photocatalytic and photoelectrochemical solar fuel production, with a focus on ammonia synthesis from photocatalytic and photoelectrochemical reduction of nitrogen and nitrate. By utilising novel semiconductor synthesis methods such as aerosol assisted chemical vapour deposition and microwave synthesis, interesting morphologies and improved activities can be obtained. It is found that nanostructured morphologies can be created on photoelectrodes through the aerosol assisted chemical vapour deposition method (CuFe2O4) and microwave synthesis can rapidly produce photocatalysts with improved photocatalytic activity for ammonia production. Through microwave synthesis of palladium doped titanium dioxide powder (Pd-TiO2), a new method of synthesising ammonia was discovered through microwave ammonia synthesis utilised in conjunction with in-situ alcohol dehydrogenation.