A method of preventing or reducing fogging of a surface of a composite
when subjected to humid conditions includes providing a composite with a
surface. The composite includes a substrate and a photocatalytic surface
layer. The photocatalytic surface layer includes a photocatalyst. The
method further includes subjecting the photocatalyst to photoexcitation
to render the surface of the composite hydrophilic, wherein, after the
photoexcitation, the surface of the composite has a water wettability of
less than 10.degree. in terms of the contact angle with water. The method
further includes subjecting the composite to humidity that is sufficient
to induce fogging of the substrate if the photocatalytic surface layer
were absent.