Precursor Development for Aerosol‐Assisted Chemical Vapor Deposition of α‐Fe₂O₃ and BiFeO₃ as Effective Photoanodes for Photoelectrochemical Water Splitting

Photoelectrochemical (PEC) water splitting holds great potential to convert solar energy into hydrogen fuel, establishing an effective method for long‐term renewable energy storage. Herein, a simple and effective approach is presented for fabricating thin films of α‐Fe 2 O 3 and BiFeO 3 for use as PEC photoanodes via aerosol‐assisted chemical vapor deposition (AACVD). A new Fe(III) precursor bearing an amino‐tris‐ tert‐ butoxide ligand is designed and coupled with a Bi‐based precursor bearing the same ligand framework to deposit nanostructured films of α‐Fe 2 O 3 and BiFeO 3 with high phase purity. Under 1 sun solar irradiation α‐Fe 2 O 3 and BiFeO 3 yielded a photocurrent density of 0.38 and 0.42 mA cm −1 at 1.23 V RHE , respectively. A study reveals that the bespoke precursors exhibit remarkable compatibility with one another, producing films of significantly higher quality compared to those produced with more conventional precursors not optimized for AACVD.