Electrochemical Deposition of Hematite α-Fe₂O₃ Thin Films for Photo-Current Generation Application

In the field of sustainable hydrogen production, hematite (α-Fe₂O₃) is a promising material owing to its optical band gap and water oxidation/reduction energies. In this context, the main objective of this work is devoted to the synthesis of α-Fe₂O₃ by electrochemical anodization of iron sheet using two anodization voltages (20 and 30 V), followed by annealing at 450°C (1.5 h) in air. Indeed, annealing is a necessary but not sufficient condition for the hematite prepared electrochemically. Furthermore, we discuss the effect of anodizing voltage and analyze its influence on the properties of the films namely structural, morphological, optical, electrochemical and photoelectrochemical (PEC) properties. The annealed Fe₂O₃ sample, anodized at 30 V, demonstrates a net photocurrent density of 0.81 mA/cm² at 0.744 V_RHE in KOH (1 M). The obtained results indicate that the α-hematite thin films synthesized by anodization technique under optimized conditions is a promising photoanode in PEC cells.