Photocatalytic Inhibition of Algae Growth Using TiO₂, WO₃, and Cocatalyst Modifications

Abstract

TiO2 and WO3, with and without noble metal cocatalysts, were employed as photocatalytic surfacing agents to inhibit the attachment and growth of Oedogonium, a sessile, filamentous algae. It was demonstrated that coating a cement substrate with a dispersion of TiO2 powder held in a 10 wt % binder and irradiating with a combination of black light and fluorescent lamps could effect a 66% reduction in the growth of algae in comparison to the unprotected cement surface. Adding a 1.0 wt % loading of a noble metal such as Pt or Ir to the photocatalyst enabled an 87% reduction. The extent of inhibition was shown to be related to the amount of near-UV light contained in the irradiation source. The ability of the photocatalysts to inhibit algae correlated well with their ability to photooxidize d-(+)-glucose, building block of numerous biochemical polysaccharides, suggesting a nonspecific mechanism in the breakdown of cellular structures.

Nanotechnology Solutions for Global Water Challenges

“…Since then, there have been a large number of research studies reporting the use of photocatalysis to inactivate microorganisms including bacteria (cells (8,9), spores and biofilms (10), viruses (11), protozoa (12), fungi (13) and algae) (14). Photocatalytic disinfection has been reviewed by several researchers including Byrne et al (15), McCullagh et al (16), Malato et al (17) and Robertson et al (18).…”

Biofouling protection for marine environmental sensors

“…Coatings with photocatalytic materials (Linkous et al 2000, Morris et al 2000 have also been studied. Unfortunately, these coatings are effective only to one meter depth.…”

Recent Developments in Accelerated Antibacterial Inactivation on 2D Cu-Titania Surfaces under Indoor Visible Light

“…In TiO 2 dispersions/suspensions made up of colloids or pre-formed powder nanoparticles, the photocatalysis led to many studies focusing on bacterial abatement [12,71,72] and showing the inactivation of spores [82][83][84][85], viruses [86], algae [87], and fungi [88]. The TiO 2 suspensions, although successful in abating a variety of pathogens under light irradiation, require times that seem to be too long to treat large water volumes.…”