Bismuth-based heterojunctions for optoelectronic and electrochemical applications

Project ID: 2228cd1363 (You will need this ID for your application)

Research Theme: Energy and Decarbonisation

UCL Lead department: Chemistry

Project Summary:

Introduction: The development of efficient materials for a sustainable infrastructure is a pressing challenge towards the global environmental crisis. Bismuth-based heterojunctions, including those based on bismuth oxyhalides, bismuth tungstate, bismuth molybdate and bismuth vanadate can result in enhanced efficiency through heterojunction assembly. Our recent publication in Appl. Cat. B: Environmental (Impact Factor 22.1) on ZnO/BiOI heterojunctions showed that there was effective charge transfer across the heterojunction leading to a significant increase in [photoelectrochemical performance] (https://doi.org/10.1016/j.apcatb.2023.122657). Aim: The aim of this project is to investigate the fabrication of bismuth based heterojunctions using the facile and low-cost method of aerosol-assisted chemical vapour deposition (AACVD). Research Importance: Many of the current preparation methods are limited, with hydrothermal or solvothermal synthesis being the most common, which require further steps to deposit powder samples into films for photocatalytic applications. For some methods scale-up production necessary for industrialisation is then challenging. AACVD is a scalable and inexpensive method for the deposition of thin films which relies on the solubility, not volatility, of the precursors. Bismuth-based materials for photocatalytic applications can show excellent visible-light responses. However, photocatalytic activity can be reduced due to recombination of photogenerated charge carries. To enhance the photocatalytic activity, the generation of heterojunctions through combination with a semiconductor or doping with other elements is necessary. While there are some reports of bismuth based thin films deposited via AACVD, the development of bismuth-based heterojunctions is limited. Project: Bismuth-based heterojunctions will be deposited via AACVD, such as ZnO/BiVO4, Bi2MoO6/TiO2, Bi2O3/BiVO4. A range of hands-on methods will be used to characterise the resulting materials including XRD, SEM, XPS and UV-Vis Spectroscopy. The resulting films and heterojunctions will be assessed for their functional properties, such as photoelectrochemical and photocatalytic applications. The influence of film deposition parameters and film thickness on the functional properties will be investigated.