Promotional effects of cetyltrimethylammonium bromide surface modification on a hematite photoanode for photoelectrochemical water splitting

Abstract

A hematite nanorod array was treated with cetyltrimethylammonium bromide (CTAB) surfactant by a simple hydrothermal method. The generated CTAB-Fe₂O₃ had double the photocurrent of pristine hematite at 1.23 V vs. RHE. We found that there was an increase of carrier density from the CTAB surface modification which favored the transport of the charge carriers. The negative electric field created on the surface of the hematite owing to the Br⁻ layer sped up the interfacial charge transfer and the oxygen evolution kinetics. Thus, there was an enhancement in the water splitting performance. The modification by CTAB on the surface of hematite was proven to be an effective approach in promoting photoelectrochemical water splitting.