Irradiation of materials with high energy (> MeV) ion beam is an effective technique to modify properties through creation of controlled and localized defects and crystallization of amorphous regions. Use of high energy ions ensures that the material is not implanted or doped, but the microstructure, morphology and the properties may be suitably modified. In the proposed work, we plan to use 100 MeV Ag (Silver) ion irradiation on TiO2 nanostructures, Graphene oxide (GO) films, and TiO2-GO nanocomposite materials and study the crystallization, microstructure and morphology before and after irradiation. Further, the effects of irradiation on the photocatalytic, gas sensing and electrochemical properties will be evaluated. In this seminar, the importance of high energy ion irradiation, the Coulomb explosion and Thermal spike models, choice of ion, energy and fluence and possible effects will be discussed.