Kinetics of the acid orange 7 degradation in the photocatalytic system of UV/H2O2/TS-1

In this paper, the titanium silicate (TS-1) molecular sieve was prepared through a rapid synthesis process, in which the tetrabutyl titanate used as titanium source, the tetraethyl orthosilicate used as silicon source and the tetrapropylammonium hydroxides used as template. A UV/H2O2/TS-1 photocatalytic system, including the light source of the high pressure mercury lamp (300 W, main wavelength of 365 nm), the oxidant of H2O2 and the photocatalyst of the prepared TS-1, was then built to investigate the kinetics of acid orange 7 (AO7) degradation. The effect of the mass concentration of TS-1, H2O2 volume fraction, initial pH value of the solution and initial concentration of the AO7 solution on the degradation rate constant (k) of the AO7 degradation was investigated. The obtained results showed that the AO7 degradation in the UV/H2O2/TS-1 photocatalytic system obeyed the first order kinetics equation. 0.2 g/L TS-1 addition, 10 mL/L H2O2 addition, 6.18 pH value was the optimal conditions for the AO7 degradation in the reaction system and the corresponding k value (0.11879 min−1) of the AO7 degradation was the highest. The azo group, the hydrogenated azo and the naphthalene of the AO7 molecules could be damaged under the optimal reaction conditions.