Influence of the triblock copolymer P123 and phosphorous on the physico-chemical properties of TiO2 Original Research Article

Nanocrystalline TiO2 powders with a high specific surface area (up to 335 m2/g) were synthesized by a combination of sol–gel and solvothermal syntheses. The influence of the TiO2 framework template, the triblock copolymer P123, and the framework stabilizer, phosphorous (P) in the form of phosphoric acid (H3PO4), on the photocatalytic oxidation of isopropanol was studied. As-prepared samples were characterized by means of X-ray powder diffraction (XRD), thermogravimetric analysis (TG-DTA), measurements of the specific surface area (sBET), field-emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM). The photocatalytic activity under UV (ultraviolet) irradiation of the as-prepared samples was measured by monitoring the degradation of the isopropanol in the gaseous medium. The application of P123 increased the specific surface area of the samples; furthermore, the addition of phosphorous inhibited the particle growth during the thermal treatment and stabilized the anatase crystal phase at higher annealing temperatures (up to 900 °C), thus leading to a higher photocatalytic activity. However, when P123 and phosphorous were used together the specific surface area was increased and an improvement in the photocatalytic oxidation was observed.