Synthesis and deposition of hematite nanoparticles on Fluorine-doped Tin Oxide (FTO) glass substrates

Abstract

Hematite has been considered to be the most popular material used as a photoanode for photo-electrochemical water splitting. However, the photo activity of hematite is limited by its low conductivity, slow water oxidation kinetics and short diffusion length of holes. Typically, nanostructuring as well as adding appropriate dopants and catalysts strategies are used to overcome the drawbacks. Here we report synthesis and the deposition of nanostructured hematite films using the hydrothermal synthesis method from an aqueous solution with 0.15 M of iron chloride hexahydrate (FeCl3∙6H2O) and ammonium hydroxide solution 25% wt. (NH4OH). To make a thin layer of hematite by hydrothermal method, ammonia and ferric chloride solution was reacted indirectly to obtain better adhesion of synthesized iron hydroxide on fluorine-doped tin oxide (FTO) glass. Results showed that β-FeOOH was uniformly formed on FTO substrates after synthesis at 120 °C for 24 hours. The Hematite photoanode can be fabricated by a thermal treatment of β-FeOOH at 550-650 °C. Synthesis procedure was characterized by X-ray diffraction (XRD), DTA and FTIR analyses. The morphologies of the synthesis nano-particle hematite layers were performed by SEM. The bandgap energy of the coated layer was calculated by UV-Vis results.