Method for photocatalytic degradation of plastic materials under visible light

A method for producing agglomerated and activated TiO2 or TiO2/MxOy to degrade a plastic material or a mixture of plastic materials, which method comprises the steps of:

• preparing and heating a surfactant-free aqueous solution at neutral pH or at a given acidic pH,
• adding to the acidic or neutral aqueous solution a precursor of titanium oxide, or a mixture of a precursor of titanium oxide TiO2 and at least one other precursor of another oxide MxOy, composed of more than 80 mol % of TiO2 and less than 20 mol % of another metal or semi-metal oxide MxOy, and stirring the acidic or neutral aqueous reaction medium,
• immersing a previously crushed plastic material or mixture of plastic materials in the acidic or neutral aqueous reaction medium,
• heating the acidic or neutral aqueous reaction medium to a temperature of between 30° C. and 90° C.,
• to condense the precursors of the acidic or neutral aqueous reaction medium on the surface of the one or more plastic materials, the precursors attaching to this surface by covalent bonds and forming the agglomerated and activated TiO2/MxOy,
• photocatalytically degrading, at neutral or acidic pH, the plastic material or the mixture of plastic materials, so as to obtain the agglomerated and activated TiO2/MxOy, without the plastic material, that is suitable for degrading one or more other plastic materials.