Electrochemical synthesis of nanosized TiO_2 nanopowder involving choline chloride based ionic liquids

摘要

The paper presents some experimental results regarding the electrochemical synthesis of TiO_2 nanopow-ders through anodic dissolution of Ti metal in choline chloride based eutectic mixtures (DES). A detailed characterization of the obtained titania has been performed, using various techniques, including XRD, Raman spectroscopy, XPS, SEM associated with EDX analysis, BET and UV-vis diffuse reflectance spectra. The anodic behavior of Ti electrode in DES has been also investigated. The photoreactivity of the synthesized materials was evaluated for the degradation of Orange Ⅱ dye under UV (λ + 365 nm) and visible light irradiation. An anodic synthesis efficiency of minimum 92% has been determined. The as-synthesized TiO_2 showed amorphous structure and a calcination post-treatment at temperatures between 400 and 600 ℃ yielded anatase. The anodically obtained nanocrystalline oxides have crystallite sizes of 8-18 nm, a high surface area and enhanced photocatalytic effect.