Use of ordered mesoporous titania with semi-crystalline framework as photocatalyst

[Display omitted] ► Titania with a high hexagonal mesopore ordering and a large surface area. ► Rates of methyl orange decomposition follow Langmuir–Hinshelwood kinetics. ► The dependence of the reaction rate on incident light intensity is first order. ► No change in the activity of the catalyst is observed at the first 4 cycles. ► The mesoporous TiO2 is able to use repeatedly. The photocatalytic degradation of water pollutants using highly ordered mesoporous TiO2 particles is an emerging area of environmental remediation. Titania particles with a high hexagonal mesopore ordering and a large surface area have been synthesized by a new surfactant templating process that combined both the evaporation-induced self assembly method and the liquid crystal templating pathway. The transformation of the amorphous titanium dioxide walls into nanosized anatase walls is obtained by calcination. The photocatalytic oxidation of methyl orange has been investigated in mesoporous TiO2 aqueous suspensions irradiated by artificial UV-light. The effect of some physicochemical parameters such as time of adsorption prior to UV irradiation, initial methyl orange concentration, photonic flux, pH and amount of photocatalyst has been analyzed in details to optimize the experimental parameters. The efficiency of the process depends on the working conditions and the optimal conditions are: 1h of dark adsorption, a TiO2 concentration of 0.5g/L, an initial methyl orange concentration of 15mgL−1 at acidic pH (pH 4) with an incident light intensity of 10−5EinsteinL−1s−1. The rates of methyl orange decomposition follow Langmuir–Hinshelwood kinetics. The dependence of the reaction rate on the incident light intensity is first order. The reproducibility of the mesoporous TiO2 as photocatalyst for methyl orange degradation is investigated during several cycles experiments. No change in the activity of the catalyst is observed at the first 4 cycles which indicates that the TiO2 is able to use repeatedly.