Titanium dioxide nanomaterials: Synthesis, properties, modifications and applications

Over the past decades, the tremendous effort put into TiO₂ nanomaterials has resulted in a rich database for their synthesis, properties, modifications, and applications. The continuing breakthroughs in the synthesis and modifications of TiO₂ nanomaterials have brought new properties and new applications with improved performance. Accompanied by the progress in the synthesis of TiO₂ nanoparticles are new findings in the synthesis of TiO₂ nanorods, nanotubes, nanowires, as well as mesoporous and photonic structures. Besides the well-know quantum-confinement effect, these new nanomaterials demonstrate size-dependent as well as shape- and structure-dependent optical, electronic, thermal, and structural properties. TiO₂ nanomaterials have continued to be highly active in photocatalytic and photovoltaic applications, and they also demonstrate new applications including electrochromics, sensing, and hydrogen storage. This steady progress has demonstrated that TiO₂ nanomaterials are playing and will continue to play an important role in the protections of the environment and in the search for renewable and clean energy technologies.