Development of UV blocking thin films with effective cut-off features with steep edges and high transmission in the visible and IR region have been developed. The unique optical, mechanical and chemical properties of silica and ceria nanocomposites with surface functional groups making them most promising candidate for applications in opto-electronic, automotive, and aeronautic industries. On the other hand, highly hydro and oleophobic films are being actively considered in optical, automotive and aeronautic industries to increase adhesion and scratch, abrasion resistance properties. In order to fill the gap, and fulfill the requirements to meet both ends, it could be proved that morphological changes in the nanometer range influences the water contact angles and their hystersis of low energy materials. Nanocomposite films of SiO2 and CeO2 with surface functionalisation with decafluorooctly-triethoxy silane itself forms nano-hemispheres (similar to lotus leaf) at and above 100°C favoring an increase in water contact angle from 122° (25°C) to 145°(400°C). The structural, optical, and hydrophobic properties have been examined by employing X-ray diffraction, UV-visible spectroscopy, contact angle techniques, respectively. The cut-off behavior of the deposited and annealed nanocomposite thin films have been tuned by varying different amounts of CeO2 in SiO2.