Synthesis of Ilmenite NiTiO3 Rods and Effect of pH on Rhodamine B Textile Dye Degradation under LED Visible-Light Irradiation

NiTiO3 rods have been synthesized and the influence of pH on their photocatalytic activity under light-emitting diode (LED) irradiation investigated. Ilmenite NiTiO3 rods were synthesized by an ethylene glycol-mediated route at room temperature, followed by calcination in air. The samples were characterized using x-ray diffraction analysis, scanning electron microscopy, ultraviolet–visible (UV–Vis) spectroscopy, and photocatalytic methods. Photocatalytic degradation of rhodamine B was carried out using NiTiO3 rods under LED visible-light irradiation. The synthesized NiTiO3 rods were in pure rhombohedral phase after calcination at 600°C for 2 h. The rods were formed from small nanoparticles of about 30 nm with porous structure. The NiTiO3 rods presented a visible absorbance response and could degrade RhB dye under visible-light irradiation. The results reveal that pH plays an important role in the photocatalytic activity of NiTiO3. The results for the removal efficiency of RhB pollutant at pH values from 1 to 11 showed a maximum at pH 3.