Elegbeleye, IMapasha, EMaluta, EMaphanga, Rapela R2026-01-062026-01-062025978-1-83769-454-9978-1-83769-455-6978-1-83769-456-3DOI: 10.5772/intechopen.1007568http://hdl.handle.net/10204/14569Titanium dioxide (TiO2) also known as titania belongs to the class of transitions metal oxides. Titanium dioxide has become a metal oxide of fascinating significance in the research sphere due to its numerous environmental and industrial applications. This chapter presents an overview of the physical, crystal, structural and semiconductor properties of TiO2 while delving into direct and indirect band gaps, fermi levels in semiconductors, density of states and carrier concentration. The environmental, pharmaceutical, deodorization, photovoltaic and water purification applications of TiO2 were also discussed. Although TiO2 clusters have become the focus of several computational studies, typical hardware has a higher processing power, giving way for the simulations of cumbersome systems, some cluster sizes used for some studies are relatively small and are not fit to handle specific problems or complex systems significant for photovoltaic applications. First-principle density functional theory calculation using computational software and GPAW that implements electron density represented on real space grids and the projector-augmented wave method were utilized in this study to investigate the optical and electronic characteristics of TiO2 brookite clusters. The results of computational investigations on the optical and electrical characteristics of different-sized TiO2 clusters and intricate systems for the purpose of simulating charge transfer mechanisms in hybrid organic-inorganic photovoltaics and photocatalytic obliteration of contaminants were presented in this chapter.FulltextenTitanium dioxidePhotocatalysisPharmaceutical applicationsTiO2 clustersDensity functional theoryBook ChapterN/A