A method and article are disclosed wherein a substrate is provided with a
photocatalytically-activated self-cleaning surface by forming a
photocatalytically-activated self-cleaning coating on the substrate by
spray pyrolysis chemical vapor deposition or magnetron sputter vacuum
deposition. The coating has a thickness of at least about 500 Angstroms to
limit sodium-ion poisoning to a portion of the coating facing the
substrate. Alternatively, a sodium ion diffusion barrier layer is
deposited over the substrate prior to the deposition of the
photocatalytically-activated self-cleaning coating to prevent sodium ion
poisoning of the photocatalytically-activated self-cleaning coating. The
substrate includes glass substrates, including glass sheet and continuous
float glass ribbon.
