Bismuth Based Semiconductors for Photocatalytic Applications University College London in United Kingdom

The development of efficient materials for a sustainable infrastructure is a pressing challenge towards the global environmental crisis and photocatalysis is one of the sustainable technologies to address some of the key problems. Bismuth-based semiconductors are considered ideal materials for photocatalysts due to the effectiveness of the bismuth ion, irrespective of its presence in different structures, when employed as a photocatalyst. Many of the current preparation methods are limited and require further steps to deposit powder samples into films for photocatalytic applications. For some methods scale-up production necessary for industrialisation is then challenging. Aerosol assisted chemical vapour deposition (AACVD) is a scalable and inexpensive method for the deposition of thin films which relies on the solubility, not volatility, of the precursors. In general, bismuth-based materials and heterojunctions, including those based on bismuth oxyhalides, bismuth tungstate, bismuth molybdate and bismuth vanadate can result in enhanced efficiency through heterojunction assembly. The photocatalytic performance of bismuth-based materials it can be attributed to the bismuth ion and the stereochemically active lone pair associated with it, which reduces the charge carriers’ recombination rate. The aim of this project is to investigate deposition of bismuth-based materials by AACVD with a detailed study on the effect of changing precursor(s), temperature, solvent and flow rate. This will then be expanded to related bismuth-based materials, an investigation of doping or the formation of heterojunctions. As well as full characterisation of the resulting thin films, this project may involve some precursor synthesis. The functional properties of the resulting thin films will be investigated.