Microwave-assisted synthesis represents a valuable improvement in theă domains of molecular and organic chemistry and was recently extended toă inorganic and materials chemistry. A comparison of titanium dioxideă nanoparticles synthesised in aqueous solution prepared in a microwave oră a conventional oven is presented here. More precisely, three differentă protocols were used in order to determine the impact of the heating modeă on the final product in terms of crystalline structure, particle sizeă and morphology. Therefore, the resultant powders were analysed by Ramană spectroscopy as well as X-ray and electron diffraction and transmissionă electron microscopy. The results show that microwave treatmentă significantly reduces the heating time and generally produces smalleră nanoparticles. The rutile/anatase/brookite phase distribution is alsoă modified by the heating mode in certain protocols up to the formation ofă a pure anatase phase, for instance. The impact of microwaves on theă solvent and on the inorganic precursors has been demonstrated. Aă photocatalytic test and time-resolved microwave conductivity experimentsă were performed on rather similar samples prepared with the two heatingă modes in order to probe the improvement of the crystalline quality andă its consequences on the photocatalytic activity of the TiO2 material.