Polyol Low-Eutectic Solvent-Assisted Preparation of Defective TiO2 for Photochemical Degradation of Organic Pollutants

This work created deep eutectic solvents (DESs) by employing ethylene glycol (EG), gamma-glycol (G), and erythritol (E) as hydrogen-bond donors (HBD) and choline chloride (ChCl) as the hydrogen bond acceptor (HBA). With DES acting as both a solvent and a carbon source, defective TiO₂ was created via the sol-gel technique. According to research, DES works well as a templating agent to reduce the size of TiO₂ particles. Oxygen vacancy defects are common in ChCl/E-TiO₂, as shown by XPS and EPR tests. The UV–vis DRS analysis and photocatalytic degradation experiments showed that the sample ChCl/E-TiO₂’s response range to light was extended to the visible and near-infrared spectra in addition to the UV spectrum. The photocatalytic degradation of methylene blue solution (MB) at 20 mg/L reached 90.3% in 2 h, which was 5.98 times higher than that of the pure TiO₂.