Photoelectrochemical nitrate sensor utilizing Cu/Pd nanoparticles on TiO2-nanoparticles carrier: Combination of catalytic and photocatalytic mechanism
TiO2-nanoparticles under UV-light irradiation are well known for photocatalytic activities due to generated electron/hole pairs. This is investigated for widespread applications like water splitting for fuel generation, wetting of surfaces, photovoltaics or destruction of germs and bacteria on contaminated surfaces. TiO2 nanoparticles combined with copper and palladium nanoparticles show selective reactions with nitrate ions in water in the presence of hydrogen. We investigated the possibility to use this catalytic reaction of Cu/Pd@TiO2 without supplying hydrogen. The supply of needed electrons to copper oxide reduction is enabled by UV-excited TiO2-nanoparticles. The newly designed material combination based only on inorganic materials gives the chance of a stable sensor system that needs no specific storage conditions enabling easy field of application usage. The results demonstrate the ability of our sensor concept to detect the requested concentration of nitrate in drinking water defined by the European Commission.