Preparation of modified nano-titanium dioxide using salycilic acid

TiO2 as a photocatalyst has band-gaps of approximately 3.0–3.2 eV, the photocatalytic process must be induced by UV light irradiation. The extreme low surface coverage of organic pollutants on the catalyst TiO2 is the key factor that has resulted in the low photocatalytic efficiency [1,2]. Thus, recent studies are focused on the modification of TiO2, including activated carbon coating, transition metal doping, metal ion implanting, surface derivating with Fe(III)-porphyrin or ascorbic acid or polymer [3]. Above mentioned modification methods are time-consuming, high cost, complicated, and furthermore, the surface coverage of organic pollutants on the catalyst TiO2 is still poor.In this work, modified nano-TiO2 was prepared by salicylic acid (SA). Surface modification was carried out through adding 3 g of the TiO2 nanoparticles into 200 mL of saturated solution of SA. A constant magnetic stirring was conducted for 30 min at room temperature until the adsorption equilibrium, resulting in a light yellow coloration of the surface of TiO2. After filtered, the surface-modified titania nanoparticles (TiO2–SA) were washed with water three times and heat treated for 30 min at 105°C. The obtained powder was then grinded to get fine particles. The powders of pure and modified nano-TiO2 were characterized by a BRUKER FT-IR spectrometer in the range 200–4000 cm−1. By comparing the FT-IR spectrum of TiO2 and TiO2-SA, it was found that the very good modified TiO2 nanoparticels were prepared.