A scalable colloidal approach to prepare hematite films for efficient solar water splitting

The development of technologically and economically viable strategies for large-scale fabrication of photoelectrodes is crucial for solar H₂ production from photoelectrochemical water splitting. Herein, a low-cost and facile colloidal electrophoretic deposition approach was developed for scalable fabrication of hematite (α-Fe₂O₃) films. Large-sized uniform films (e.g. 80 mm × 70 mm) with tailored thickness and nanostructures can be easily prepared on conductive substrates within 2 minutes. The resultant films showed a high photocurrent of ∼1.1 mA cm^-2 at 1.23 V_RHE under standard AM 1.5G illumination, which is among the highest reported values achieved on hematite films prepared using other complex colloidal approaches. The present work will pave a new avenue for fabrication of efficient photoelectrodes toward practically viable solar H₂ production.