This chapter discusses Titanium dioxide (TiO2) fabrication and its photocatalytic application. The review examines the basic principles of photocatalytic H-2 production, degradation of pollutants, CO2 reduction, and N-2 reduction using TiO2 photocatalysts under ultraviolet light conditions. The focus includes synthesis and modification of TiO2 nanophotocatalysts for improved photocatalytic applications. The synthesis methods examined contains the sol gel, sol, hydrothermal, solvothermal, vapor deposition, electrochemical, direct oxidation, surfactant controlled, and the plasma-assisted process. The photocatalytic activities of pure TiO2 suffer from limitations such as the fast charge carrier recombination and its wide bandgap of approximately 3.2 eV. Improving the photocatalytic activities of TiO2 has been the focus of many reports. Modifications of TiO2 consist of changing the crystal structure and morphology, doping with metal and nonmetal chemicals, incorporating carbon materials (carbon nanotubes and graphene), and noncarbon materials (i.e., metals, semiconductors, dyes, and noncarbonaceous two-dimensional materials). Lastly, future prospects are discussed for the application of TiO2.