Titanium dioxide (TiO2) loaded with gold (Au) as noble metal, acts asan efficient photocatalyst that has been extensively investigated for watersplitting processes. In this paper, we report on the microstructure of atomiclayer deposited titanium dioxide and the crystallinity modification of thematerial using energetic electron beam irradiation. A rapid high-energy electronbeam induced crystallization of the nanostructures has been observedin-situ inside a High-Resolution Transmission ElectronMicroscope (HRTEM). The systematic crystallization of the nanomaterial occurringunder the electron beam irradiation (300 KV) indicates the transformation of thenear amorphous material into a mixture of two nuances of TiO2polymorphs, namely rutile and anatase. We believe that this transformation willenhance the efficiency of water splitting process, as the mixed phases of rutileand anatase are known to possess better optical properties than the individualpolymorphs of TiO2. This finding may be of particular interest indeveloping appropriate heat treatment methods for these nanostructures dedicatedto water splitting to increase their efficiency.