Photochemical template removal and spatial patterning of zeolite MFI thin films using UV/ozone treatment

This paper describes an application of a non-thermal, photochemical calcination process for an efficient and spatially controlled removal of the organic structure-directing agent in the preparation of thin films of microporous or zeolite materials. We prepared thin-films of a high silica zeolite (structure code: MFI) following a previously published procedure. The films were illuminated using an ozone generating short-wavelength ultraviolet light in ambient environments and characterized using Fourier-transform infrared spectroscopy, imaging ellipsometry, thin-film X-ray diffraction, and scanning electron microscopy. Results presented here indicate that the UV/ozone treatment under nominally room temperature conditions leads to complete removal of template (structure-directing-agent) from zeolite films comparable to that achieved by thermal calcination. Furthermore, spatially addressing the UV/ozone illumination pattern using a physical mask resulted in the lateral confinement of the template removal from the zeolite film leaving behind a composite film composed of templated and template-free regions. Subsequent chemical treatment of the patterned film selectively removed the as-synthesized, unexposed, regions of the film thereby providing a means for the creation of isolated zeolite film islands at predetermined locations on the substrate surface.