Liu, GuanyuKaruturi, Siva KrishnaChen, HongjunWang, DunweiAger, Joel WSimonov, A. N.Tricoli, Antonio2021-02-220038-092Xhttp://hdl.handle.net/1885/223934Ferroelectric semiconductors like BiFeO3 are increasingly being investigated for applications in solar energy conversion and storage due to their intrinsic ability to induce ferroelectric polarization-driven separation of the photogenerated charge carriers resulting in above-bandgap photovoltages. Nevertheless, the BiFeO3 has been commonly prepared using complex and expensive fabrication techniques, e.g., epitaxial growth, radio frequency sputtering and pulsed laser deposition, which are not economically viable for large-scale production. Herein, we report a facile and scalable method for the fabrication of porous perovskite BiFeO3 photoanodes, as well as sequential interfacial engineering methods to enhance their photoelectrochemical performance for water splitting. Upon atomic layer deposition of a TiO2 overlayer and photo-assisted electrodeposition of a cobalt oxide/oxyhydroxide co-catalyst, the photocurrent density of the engineered photoanode for oxygen evolution reaction (1 M NaOH) significantly increased from negligible photocurrent of the pristine BiFeO3 to 0.16 mA cm−2 at 1.23 V vs. reversible hydrogen electrode (RHE) under simulated 1 sun irradiation (100 mW cm−2, AM1.5G spectrum). Furthermore, such functionalization of the BiFeO3 photoanodes shifts the photoelectrochemical oxidation onset potential by 0.7 V down to 0.6 V vs. RHE. The significantly enhanced photoelectro-oxidation activity is facilitated by the improved charge transfer and electrochemical kinetics.D.W. acknowledges support from the National Science Foundation (CBET 1703662, United States). A.N.S. are grateful for the financial support from the Australian Research Council via the Center of Excellence for Electromaterials Science (CE140100012). J.W.A. acknowledges the financial support of the Singapore National Research Foundation under its Campus for Research Excellence and Technological Enterprise (CREATE) program through the Cambridge Center for Advanced Research and Education in Singapore (CARES) and the Berkeley Educational Alliance for Research in Singapore (BEARS) eCO2EP program. Access to the facilities of the Centre for Advanced Microscopy (CAM) with funding through the Australian Microscopy and Microanalysis Research Facility (AMMRF) is gratefully acknowledged. The authors also acknowledge the Australian National Fabrication Facility (ANFF) for financial support and access to experimental facilitiesapplication/pdfen-AU© 2020 International Solar Energy Society. Published by Elsevier Ltd. All rights reserved.BiFeO3 Interfacial engineeringFerroelectricPerovskitePhotoelectrochemical water splittingInterfacial engineering202010.1016/j.solener.2020.03.1172020-11-15