Fabrication and Characterization of Hematite/Titanium Dioxide Photocatalyst for Hydrogen Production

Abstract

This research aims to the development of photocatalytic α-Fe2O3/TiO2 for hydrogen production by using noble metal deposition and plasma treatment. This study was to modification of heterojunctions of hematite (α-Fe2O3) deposition on titanium dioxide (TiO2) and Palladium (Pd) co-catalyst. As the result of the characterization, the average crystallite size of ternary α-Fe2O3/TiO2-Pd was 22 nm and its band gap energy was 2.00 eV, much lower than that of the pure TiO2 nanoparticles (3.16 eV). The α-Fe2O3/TiO2-Pd also has higher specific surface area and smaller EIS radius, which enhance interface activity and charge transfer. The α-Fe2O3/TiO2-Pd exhibited great performance, with H2 production rate of 3490.54 µmol h-1 g-1 and excellent stability in multi-cycle H2 production. Plasma modification on α-Fe2O3/TiO2 photocatalyst, the crystalline phase of TiO2 form changed from pure anatase to a mixture of anatase and rutile phases. The particle size was reduced from 25 to 20 nm. The band gap energy decreased from approximately 2.18 eV to 1.84 eV and exhibited a wider absorption edge under visible light irradiation (400–700 nm). The charge transfer resistance was reduced from 2.24 to 1.90 kΩ. Ar-plasma modification of the surface showed the attribution of oxygen vacancies and Ti3+. The plasma treatment improved the heterojunction photocatalyst to enhance the photocatalytic activity under visible light for H2 evolution. The best photocatalytic activity for H2 evolution rate was obtained at 1.25 mmol h-1 for α-Fe2O3/TiO2-10 photocatalyst