Titania (TiO2) is suitable for several environmental applications such as air purifier, waste water treatment cleaning, water disinfection and photo-induced hydrophilic coating with self-cleaning properties. It can be incorporated in bulk concrete, mortars, ceramic or as a coating on glass and stone. Degradation of gases in the atmosphere, both indoor and outdoor, such as NOx, carbon monoxide, VOCs, chlorophenols, and aldehydes from vehicle and industrial emissions, take place on a surface enriched with Titania nanoparticles. Also, partially replacing cement with nano TiO2 particles in a cementitious matrix achieves high compressing and flexural strength. Titania also accelerates the early age hydration of Portland cement. Another well studied and used photocatalytic nanomaterial is the ZnO. Lastly, another nanomaterial recently studied as a photocatalyst is graphene. Graphene is a flat monolayer of carbon atoms with perfect two-dimensional carbon structure. It has high conductivity, electron mobility, and high specific surface area and thus the composites of metal oxides with graphene can lead to a variety of environmental and energy-related applications.