Photocatalytic degradation of p-cresol by zinc oxide under UV irradiation

Int J Mol Sci. 2012;13(1):302-15. doi: 10.3390/ijms13010302. Epub 2011 Dec 27.

Abstract

Photocatalytic degradation of p-cresol was carried out using ZnO under UV irradiation. The amount of photocatalyst, concentration of p-cresol and pH were studied as variables. The residual concentration and mineralization of p-cresol was monitored using a UV-visible spectrophotometer and total organic carbon (TOC) analyzer, respectively. The intermediates were detected by ultra high pressure liquid chromatography (UPLC). The highest photodegradation of p-cresol was observed at 2.5 g/L of ZnO and 100 ppm of p-cresol. P-cresol photocatalytic degradation was favorable in the pH range of 6-9. The detected intermediates were 4-hydroxy-benzaldehyde and 4-methyl-1,2-benzodiol. TOC studies show that 93% of total organic carbon was removed from solution during irradiation time. Reusability shows no significant reduction in photocatalytic performance in photodegrading p-cresol.

Keywords: UV; ZnO; mineralization; p-cresol; photocatalytic degradation.

MeSH terms

  • Catalysis
  • Chromatography, High Pressure Liquid
  • Cresols / chemistry*
  • Cresols / metabolism
  • Hydrogen-Ion Concentration
  • Kinetics
  • Photolysis / radiation effects
  • Ultraviolet Rays*
  • Water Pollutants, Chemical / chemistry*
  • Water Pollutants, Chemical / metabolism
  • Zinc Oxide / chemistry*

Substances

  • Cresols
  • Water Pollutants, Chemical
  • 4-cresol
  • Zinc Oxide