The photocatalytic degradation of organic contaminants on titanium dioxide is basically non-selective. While this seems at first glance to be an advantage, this is not the case when a stream containing low concentrations of highly toxic substances together with high concentrations of low-toxic organics has to be treated.
A method for obtaining preferential degradation by means of preparation of molecularly imprinted photocatalyst is presented hereby. The method is demonstrated with two model compounds simulating the nerve gas Sarin: Diisopropyl methyl phosphonate (DIMP) and Diethyl hydroxymethyl phosphonate (DEHMP).
An improvement by a factor of 3 for these compounds was obtained upon imprinting. This enhancement in the degradation rates was not observed when using the molecularly imprinted photocatalyst for the degradation other molecules, thus negating the possibility that the increase in the degradation rates originated from enhanced surface area.
Effects on the appearance of by-products, ways to further increase the efficiency, and the prospects and limitations of this method will be discussed.