Photocatalytic Degradation of 4-Chlorophenol by Titanium Dioxide: Role of Annealing Temperature and Morphology

This work investigates the degradation rate of 4-cholorophenol using titanium dioxide photocatalysts. chlorophenols and their compounds are a nuisance as they are recalcitrant to degradation in the environment. three morphologically different titanium dioxide catalysts, a, b and c, were immobilized on microscopic glass at a layer of 0.5 mg/cm^2 and annealed between 500-700°c. the three different tio_2 powders were characterized using scanning electron microscopy, x-ray diffraction and brunauer emmett teller to determine their specific surface area, crystalline and particle sizes. a four–position photocatalytic reactor illuminated by two ultra violet lamps of wavelength range 320-400 nm and intensity i = 27.87 mw/m^2 was used to degrade the 4-chlorophenol in 2 hrs. aliquots of the degraded 4- chlorophenol were drawn every 30 minutes and analyzed using uv-vis spectroscopy at λ=226 nm. the optimum annealing temperature of all tio_2 was found to be 650°c, with type b of hexagonal morphological structure and particle size of 28±2nm having the highest 4-chlorophenol degradation rate, of 71.21%.