Kinetic study for 4-chlorophenol photodegredation in the presence of TiO2

Abstract EN

The effects of non-porous powder samples of TiO2 with specific surface areas about 55 m2g-1 on the kinetics of disappearance of 4-chlorophenol (4-CP) in water, under illumination at λ ≥ 340 nm (to avoid the direct photolysis of 4-CP) and 298 K, were determined.

The photocatalytic character of the 4-CP disappearance in its presence was shown by (i) the effects of the catalyst mass on the initial rate ro, (ii) the Langmuirian–type relationship between ro and Co (iii) the very lowl activation energy of 4-CP disappearance (iV) the effect of pH of the medium, (V) the effect of initial concentration Co of 4-CP on the rate of photodegradation ro.

Hydroquinone HQ is the main intermediate in the degradation and none of the toxic biphenyl derivatives produced by direct photolysis was found in presence of TiO2.

Complete mineralization of 4-CP was eventually obtained, the degradation produced more numerous and more stable aromatic intermediates, as shown by high performance liquid chromotography HPLC tests.