Nanomaterials have applications in various fields such as microelectronics, electromagnetism, optoelectronic and in biomedical, pharmaceutical and cosmetics chemistry. In particular, pure TiO2 nanoparticles have different properties according to their structure. For example, crystallisation in the anatase form favours photocatalytic activity as compared to the rutile organisation. Doped TiO2 nanoparticles are also very useful for various catalytic reactions. Moreover, incorporation of heteroatoms may favour photocatalytic activity and absorption of solar light. Different methods such as sol-gel chemistry and flame spray pyrolysis are often used for the synthesis of TiO2 nanoparticles. At laboratory scale, the TiO2 anatase form and various doped TiO2 nanoparticles have been obtained by these methods.