The heterojunction effect of Pd on TiO2 for visible light photocatalytic hydrogen generation via water splitting reaction and photodecolorization of trypan blue dye

Abstract

In this work, we reported synthesis of Pd/TiO2 NPs at 130 °C in 1 day using an ionic liquid assisted hydrothermal method using methoxyethyl methyl imidazolium methanesulfonate as the ionic liquid, Titanium (IV) isopropoxide and Palladium nitrate as precursors. Physico-chemical properties of the obtained photocatalysts were investigated via thorough characterizations. The framework substitution of Pd in TiO2 NPs was established by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and energy dispersive X-ray spectroscopy (EDS) techniques. X-ray diffraction (XRD) and transmission electron microscopy (TEM) image results confirmed the anatase phase and nanocrystalline nature of Pd/TiO2. The optical properties revealed an extended tailing of the absorption edge toward the visible region upon Pd heterojunction. The concentration of Pd in the TiO2 matrix has been fine-tuned to improve the hydrogen production, and Photodecolorization of trypan blue dye. The synergy between the Pd and TiO2 has an optimum for concentration of 0.3 wt% Pd doped TiO2. The optimized product has produced promising hydrogen evolution of 1250 µmol g−1 under illumination with a visible light source in a water/ethanol system. The optimized product has shown promising photocatalytic detoxification ability of the material towards trypan blue dye was explored.