Kinetic Study for the Photocatalytic Degradation of Acetic Acid over Zinc Oxide

Abstract

Photocatalytic degradation of acetic acid over zinc oxide suspended as a
photocatalyst was done , under irradiation with ultraviolet light .
The photocatalytic degradation of the acid was followed by using (IR) spectroscopy ,
which exhibits reduction in the intensity of absorption of carboxyl group of the acid .
The remaining quantity of the acid was determined by spectrophotometric method by
using a standard calibration curve of standard solutions of the acid . The reaction was
done at three different temperatures293,298,and 303 K. The effect of temperature on the
rate of reaction used in the estimation of activation energy for the reaction according to
Arrhenius plot , the activation energy was about (22)kJ . mol-1 . Langmuir kinetic model
was applied for the reaction , it used in the estimation of an approximate adsorption
equilibrium constant which was about (1.8 × 10-4 l . mol-1) . Rate constant for the
reaction was calculated by plotting of invers of rate of the reaction versus invers of
concentration of the used acid which was equal to (4.5 × 10-6) sec-1 .