Utilization of Nickel ferrite (NiFe₂O₄) in Hematite (α-Fe₂O₃) Photoanode for Photoelectrochemical Water Splitting as a Blocking Layer

We found a new blocking layer (nickel ferrite, NiFe2O4), that could be utilized for the suppression of the back recombination, occurring in the hematite (alpha-Fe2O3) photoanode. The photoanode in which the NiFe2O4 layer was introduced showed a cathodic shift of the onset potential in the current density versus applied voltage curve. We successfully demonstrated that the NiFe2O4 layer effectively inhibited the back recombination in the hematite film through the use of electrochemical and time-resolved spectroscopic methods.