Eosin Y-sensitized nitrogen-doped TiO 2 for efficient visible light photocatalytic hydrogen evolution

Abstract

A nitrogen-doped TiO 2 (N-TiO 2) photocatalyst was prepared by the calcination of the hydrolysis product of Ti(SO 4) 2 with aqueous ammonia. Pt was loaded on N-TiO 2 by photodeposition method. A dye-sensitization photocatalyst was prepared by impregnation method with Eosin Y and the platinized N-TiO 2. The prepared samples were characterized by XRD, UV–vis diffuse reflectance spectra (DRS), BET and FT-IR. The visible light activity of the sensitization photocatalysts was evaluated by photocatalytic hydrogen evolution ( λ > 420 nm) in the presence of electron donor triethanolamine (TEOA). The N-TiO 2 has smaller crystalline size and larger specific surface area to enhance the adsorption amount of Eosin Y than TiO 2 prepared by NaOH. Surface oxygen defects produced by nitrogen doping would improve the adsorption of Eosin Y and excited electron to transfer to the conduction band of N-TiO 2. Therefore the visible light activity of the sensitized nitrogen-doped platinized TiO 2 is much higher than that of the sensitized platinized TiO 2. The sensitized nitrogen-doped platinized TiO 2 calcined at 300 °C has the highest visible light activity among the catalysts calcined at various temperatures, whose activity is increased by a factor of 3 compared to that of the sensitized platinized TiO 2 calcined at the same temperature.