摘要
Alkaline hydrogen peroxide treatment was proposed as a simple and green way to improve the performance of commercial TiO 2 powder for water-dispersibility and visible-light photocatalytic activity on the degradation of dye pollutants. The performance of treated TiO 2 was evaluated as a function of NaOH concentration, H 2 O 2 concentration, and treatment time. The optimal conditions were determined to be 24 h in 100 mM H 2 O 2 and 8 M NaOH. The treated samples were characterized by Raman spectroscopy, high-resolution transmission electron microscopy (HR-TEM), X-ray photoelectron spectroscopy (XPS), dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FTIR), and ultraviolet-visible spectrophotometry. The analysis revealed that the crystal structure, morphology, and absorption band gap were retained, but the surface of the treated TiO 2 was dramatically changed. The treated TiO 2 was highly dispersible with a uniform hydrodynamic size of 41 ± 12 nm and stable over months in water at pH 3 without any stabilizing ligand and could significantly enhance the visible-light photodegradation of dye pollutants. The superior performance might be attributed to the formation of abundant surface hydroxyl groups. This treatment paves the way for developing water-dispersible TiO 2 with superior visible-light induced photocatalytic degradation of dye pollutants without any complicated and expensive surface modification.