The present invention relates to a mixture, comprising at least one thermoplastic polymer as component (A) and at least one photocatalytically active particle, comprising a non-porous core comprising at least one metal oxide or semimetal oxide with a diameter of from 0.1 nm to 1 μm, and, at least to some extent surrounding the core, at least one porous outer layer comprising at least one further metal oxide or further semimetal oxide with an average layer thickness of from 0.1 to 10 nm, as component (B), to a process for the production of this mixture according to any of claims 1 to 5, via mixing of components (A) and (B), to the use of the mixture as photocatalytically active surface, to moldings, comprising this mixture, and to the use of this mixture for the production of moldings.