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

Abstract

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-Fe2O3 and BiFeO3 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-Fe2O3 and BiFeO3 with high phase purity. Under 1 sun solar irradiation α-Fe2O3 and BiFeO3 yielded a photocurrent density of 0.38 and 0.42 mA cm−1 at 1.23 VRHE, 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.