Coupled photocatalytic reactions for dehalogenation of polychlorinated hydrocarbons and generation of molecular hydrogen

The quantum yields of photocatalytic generation of hydrogen ( ) from alcohol-water mixtures containing a suspension of Pd/CdS (or CdS and Pd/SiO₂) increase in the presence of CCl₄ or C₆Cl₆ additives, which undergo dehalogenation. The reasons for the increase in are the increase in acidity during the process, and also suppression of electron-hole recombination as a result of acceptance of electrons from the conduction band by the halogenated hydrocarbons, which leads to generation of additional amounts of ethoxy radicals taking part in reduction of water. L. V. Pisarzhevskii Institute of Physical Chemistry, National Academy of Sciences of Ukraine, 31 Prospekt Nauki, Kiev 252039, Ukraine. Translated from Teoreticheskaya i éksperimental'naya Khimiya, Vol. 35, No. 3, pp. 162–166, May–June, 1999.