The influence of inorganic oxidants and metal ions on semiconductor sensitized photodegradation of 4-fluorophenol

This paper mainly focuses on the influence of inorganic oxidants and metal ions on the TiO2, ZnO sensitized photodegradation of 4-fluorophenol (4-FP) by UV-A light. TiO2-P25 is more efficient than ZnO. Among the oxidants periodate ion was found to be more efficient than others in improving the degradation of 4-FP via formation of reactive radicals. The effect of oxidants on the degradation of 4-FP was found to be in the order of IO4− > BrO3− > S2O82− H2O2 > ClO3−. The effect of metal ions on degradation of 4-FP was found to be in the order of Mg2+ > Fe3+ > Fe2+ > Cu2+. The degradation of 4-FP follows pseudo-first order kinetics according to the Langmuir–Hinshelwood model. The photomineralisation has also been confirmed by COD, gas chromatography and fluoride ion measurements.