Scaling up BiVO4 Photoanodes on Porous Ti Transport Layers for Solar Hydrogen Production

Commercialization of photoelectrochemical (PEC) water-splitting devices requires the development of large-area, low-cost photoanodes with high efficiency and photostability. Herein, we address these challenges by using scalable fabrication techniques and porous transport layer (PTLs) electrode supports. We demonstrate the deposition of W-doped BiVO4 on Ti PTLs using successive-ionic-layer-adsorption-and-reaction methods followed by boron treatment and chemical bath deposition of NiFeOOH co-catalyst. The use of PTLs that facilitate efficient mass and charge transfer allowed the scaling of the photoanodes (100 cm(2)) while maintaining similar to 90 % of the performance obtained with 1 cm(2) photoanodes for oxygen evolution reaction, that is, 2.10 mA cm(-2) at 1.23 V vs. RHE. This is the highest reported performance to date. Integration with a polycrystalline Si PV cell leads to bias-free water splitting with a stable photocurrent of 208 mA for 6 h and 2.2 % solar-to-hydrogen efficiency. Our findings highlight the importance of photoelectrode design towards scalable PEC device development.

Automated summary

The commercialization of photoelectrochemical water-splitting devices faces challenges such as large-area, low-cost photoanodes with high efficiency and photostability. This study addresses these challenges by using scalable fabrication techniques and porous transport layer electrode supports. The results show that it is possible to scale up the photoanodes while maintaining high efficiency and stability, and integrate them with polycrystalline Si PV cells for stable water splitting.