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

Abstract

AbstractCommercialization 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 cm2) while maintaining ~90 % of the performance obtained with 1 cm2 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.