We have developed a new photocatalyst film in which platinum-loaded TiO2 and poly(tetrafluoroethylene) (PTFE) particles are immobilized. A rapid and complete degradation of trichlorobenzene in dilute aqueous solutions is achieved using these films under illumination. The decomposition rate of the target compound is found to be enhanced resulting from the efficient consumption of photogenerated electrons and holes in the reduction of oxygen and the oxidative degradation of trichlorobenzene, respectively.