This invention relates to a photosensitizer which is bound to a polysiloxane polymer, a method of preparing the bound photosensitizer and a process for using the bound photosensitizer. The photosensitizers which may be used in the invention include rose bengal, rhodamine B, acridine orange, methylene blue and zinc phthalocyanine. The photosensitizer is attached to the polysiloxane by reacting a hydroxyl or vinyl group on the photosensitizer with a hydrogen on the polyhydrosiloxane, thereby binding the photosensitizer into the polymer network. Finally, the bound photosensitizer may be used to oxidize undesirable oxidizable compounds present in a hydrocarbon or aqueous fraction. One specific example is the sweetening of kerosene which involves oxidizing the mercaptans contained in the kerosene.