A hybrid titania-silica cold-setting sol has been developed that can be deposited onto a wide variety of surfaces without the need for high-temperature fixing and that is suitable for material printing deposition. Thin hybrid titania-silica coatings were patterned onto glass and PET substrates by inkjet printing. Well-defined hybrid titania-silica patterns, with thicknesses ranging from 40 to 400 nm, were fabricated by overprinting 1 to 10 layers. Excellent mechanical, optical, and photocatalytic properties were observed, making the reported material well suited for the fabrication of transparent self-cleaning coatings both on mineral and organic substrates. The printed patterns exhibit photoelectrochemical activity that can be further improved by thermal or photonic curing. A concept of fully printed interdigitated photoelectrochemical cells on flexible PET substrates utilizing the reported hybrid photocatalyst is disclosed as well.
Keywords: binder; direct patterning; inkjet printing; material printing; photocatalysis; silica; titanium dioxide.