Demonstration of up-scalable BiVO4-based materials from aerosol-assisted chemical vapour deposition with 36 cm2 irradiation area in a prototype photoelectrochemical water splitting device
George Creasey a, Tristan McCallum b, Liam O'Neil a, John Wilman Rodriguez Acosta a, Andreas Kafizas b c, Anna Hankin a d
a Department of Chemical Engineering, Imperial College London, SW7 2AZ, UK, Imperial College Road, London, United Kingdom
b Department of Chemistry, Imperial College London, W12 OBZ, UK
c London Centre for Nanotechnology, Imperial College London, SW7 2AZ, UK
d Institute for Molecular Science and Engineering, Imperial College London, SW7 2AZ, UK
Proceedings of Catalyst Design Strategies for Photo- and Electrochemical Fuel Synthesis (ECAT23)
Keele, United Kingdom, 2023 December 4th - 5th
Organizers: Charles Creissen, Qian Wang and Julien Warnan
Poster, George Creasey, 028
Publication date: 10th October 2023

While hydrogen production via photoelectrochemical (PEC) water splitting has been demonstrated on a small scale, developing an industrial scale device is a challenge that intrigues and brings together researchers from a range of disciplines. A key bottleneck in the scalability of PEC devices remains the development of scalable photocatalyst materials for the water splitting reaction. Many photoelectrodes are produced as thin films on transparent conducting oxides, such as fluorine-doped tin oxide (FTO) or indium-doped tin oxide (ITO). However, one difficulty to overcome is the resistivity of FTO glass, which can result in severe resistance losses in scale-up. I will present the initial steps we have taken to mitigate this issue.


I will present our method of photoanode fabrication by chemical vapour deposition, a prevalent and scalable method, of sequential layers of WO3 nanorods and BiVO4, to form a staggered heterojunction on FTO. The 2.4 - 2.5 eV bandgap of BiVO4 enables light absorption up to 517 nm in wavelength and a theoretical solar-to-hydrogen efficiency (ɳSTH) of up to 9.2 %. The WO3/BiVO4 heterojunction system is one of the most promising in terms of performance, cost and durability. Combined with a Ni mesh cathode and homojunction Si PV, and operated in a pH neutral phosphate buffer solution, this creates a cost-effective and scalable tandem photoelectrochemical-photovoltaic (PV-PEC) device with a commercially viable fabrication method.


However, another challenge to address is the PEC stability of BiVO4-based photoanodes, which are prone to photocorrosion in aqueous solutions, particularly at non-neutral pHs, negative electrode potentials and highly positive electrode potentials. I will present our initial work to mitigate this issue, by tuning electrolyte composition, through the use of co-catalysts, doping, different electrolytes and varying fabrication[HA1] conditions to alter the structural morphology of the photoanodes. In preliminary results, BiVO4 electrodes containing 6% Mo had a photocurrent density at 1.23 VRHE that was five times higher than undoped BiVO4 electrodes, while PEC degradation rates were considerably reduced.


This research seeks to elucidate challenges of developing up-scaled materials for water splitting, to facilitate the pathway to commercially viable photoelectrochemical hydrogen production.


Key words

Photoelectrochemistry, hydrogen, scale-up, electrochemical engineering, BiVO4

and different electrolytes [HA1]

We use our own and third party cookies for analysing and measuring usage of our website to improve our services. If you continue browsing, we consider accepting its use. You can check our Cookies Policy in which you will also find how to configure your web browser for the use of cookies. More info