Ionic liquid-assisted hydrothermal synthesis of TiO₂ nanoparticles and its application in photocatalysis

Anatase TiO₂ nanoparticles have been successfully synthesized at 130 °C for 2 days via ionic liquid-assisted hydrothermal method. The obtained products are characterized using various techniques. The X-ray diffraction data reveal that the nanoparticles are anatase TiO₂. FTIR spectrum shows that the presence of ionic liquid and indicates Ti–O–Ti peak at around 398 cm⁻¹, and the bands at 1500 and 1600 cm⁻¹ indicates C–H in-plane vibrations and stretching of imidazolium ring. Raman spectroscopy show bands at 142, 393, 513, and 636 cm⁻¹ reveal crystalline anatase phase. UV–Vis spectroscopy shows the λ _max at 355 nm corresponding to a band gap of 3.49 eV. TEM images reveal that the average diameters of anatase TiO₂ nanoparticles are in the range 50–100 nm. Anatase TiO₂ exhibited excellent photocatalysis for the degradation of organic dye.