Substrate Fabrication
To demonstrate the PH2OTOGEN device concept, a robust, transparent, and porous substrate for the photocatalyst particles is needed. WP4 is dedicated to this task. SiO2 fibres, selected for their transparency and mechanical robustness, are processed to form a monolithic semi-transparent scaffold sheets over 100 cm² in area. A key advance in the of WP4 has been tuning the fibre quantity and annealing temperature to retain suitable porosity and transparency and improve the sheets' mechanical robustness. Accordingly, we have obtained scaffolds that can support 12 times more weight compared to the previous results, allowing us to achieve several internal milestones.
Deposition of Transparent Conductive Layer
Next, to enable efficient charge transport between oxidizing particles (OP) and hydrogen-evolving particles (HEP), the 100 cm² substrate was coated with a transparent conductive oxide (TCO) layer. Using ultrasonic spray pyrolysis, a uniform fluoride-doped tin oxide (FTO) film was deposited, ensuring excellent electrical conductivity without significantly compromising transparency.
Kevin Sivula, Professor of Chemical Engineering, Laboratory for Molecular Engineering of Optoelectronic Nanomaterials (LIMNO), EPFL
Benjamin Goldman, Ph.D Student at the Laboratory for Molecular Engineering of Optoelectronic Nanomaterials (LIMNO), EPFL