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

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.