| Abstract
| - TiO2 and WO3, with and without noble metal cocatalysts,were employed as photocatalytic surfacing agents to inhibitthe attachment and growth of Oedogonium, a sessile,filamentous algae. It was demonstrated that coating acement substrate with a dispersion of TiO2 powder heldin a 10 wt % binder and irradiating with a combination ofblack light and fluorescent lamps could effect a 66%reduction in the growth of algae in comparison to theunprotected cement surface. Adding a 1.0 wt % loadingof a noble metal such as Pt or Ir to the photocatalyst enabledan 87% reduction. The extent of inhibition was shown tobe related to the amount of near-UV light contained in theirradiation source. The ability of the photocatalysts toinhibit algae correlated well with their ability to photooxidized-(+)-glucose, building block of numerous biochemicalpolysaccharides, suggesting a nonspecific mechanism inthe breakdown of cellular structures.
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