Nanostructured Catalysts for Environmental Applications

Abstract

Introduction There are two areas of interest in environmental technology where nanocatalysts are potentially useful. These areas include (i) reduction of the pollutant emissions (ii) decrease of the concentration of already existing pollutants. Two specific materials to exemplify these two types of nanocatalysts are discussed. TiO2 has been known to be a photocatalyst for the degradation of various organic and inorganic pollutants.[1-3] The nanostructure plays in increasing the photocatalytic efficiency of TiO2. Doping with the appropriate dopant can also help increase the photocatalytic efficiency and cause red shift in the band gap of TiO2 making it absorb in the visible range. For emission control of the pollutants, specifically, for NOx, a precious metal (Pt, Pd, Ru, Rh etc.) or a toxic gas (ammonia) is used. There is a need for an alternative catalyst. A potentially important and low cost alternative is WCx.[4-5] The synthesis and characterization of WCx nanoparticles is