Reductive dehalogenation of dichloroacetic acid at SiC-photocathodes

Due to the toxicity of halogenated organic compounds, there is a need for t heir elimination in natural, drinking and industrial waste waters. The reductive dehalogenation by photoelectrolysis may be an alternative pro cedure for the remediation of organic halides from aqueous solution. In thi s work a semiconductor electrode (SiC) was used as photocathode for the red uction and cleavage of the carbon-halogen-bond, and the photo-electrochemic al properties of single crystalline p-doped SiC are described. Chlorinated acetic acids were chosen as model compounds for the dehalogenat ion at irradiated cathodes. Trichloroacetic acid was step by step selective ly reduced to di- and monochloroacetic acid under the given experimental co nditions. Dichloroacetic acid was reduced to monochloroacetic acid, while t he reductive dehalogenation of monochloroacetic acid revealed to be rather difficult.