Photocatalytic degradation of 1-naphthol by oxide ceramics with added bacterial disinfection

1-Naphthol photodegrades on the surfaces of TiO2, ZnO, CeO2, CdO, WO3, Co3O4, Sb2O3, ZrO2, La2O3, Y2O3, Pr6O11, Sm2O3 and Al2O3, albeit at different efficiencies, and all the oxides show sustainable photocatalytic activity. The degradation conforms to the Langmuir-Hinshelwood kinetic model and enhances with the intensity of illumination. Dissolved oxygen is essential for the degradation. ZnO and TiO2 anatase are the most efficient photocatalysts to degrade 1-naphthol. ZnO wurtzite, besides serving as an effective photocatalyt to degrade 1-naphthol, also acts as a bactericide; it inactivates E.coli even in absence of direct light. At a loading of 0.8 g L-1, it kills about 44% of 2.5 x 10(12) CFU mL(-1) E. coli in 1/2 h under dark condition. (C) 2010 Elsevier B.V. All rights reserved.