Possible Environmental Risks of Photocatalysis used for Water and Air Depollution - Case of Phosgene Generation

Abstract This short review presents some deficiencies regarding photocatalysis used for water and air depollution, because the environmental risks have to be considered in order to minimize negative effects of the future applications. Since photocatalysis was discovered a couple of decades ago, it was intensively studied and many applications were developed. In the environmental engineering depollution ex-situ and in-situ of water and air, using photocatalysis, seems to be revolutionary. Deficiencies of these processes are concerning in formation of undesirable secondary products. Some of the processes involving photocatalysis could degrade efficient by-products, but there are situations when these products seem to be more toxic than initially pollutant. One of these cases, phosgene generation during air depollution, is detailed in a scenario, using related researches and simple calculus. The result proves the environmental risk of organochlorine compounds oxidation by photocatalytic processes.