Elegbeleye, IMaluta, EMaphanga, Rapela RWalter, MBrügner, OZendehdel, MNia, NYSamer, M2024-11-112024-11-112024-09978-0-85466-880-9978-0-85466-881-6DOI: 10.5772/intechopen.1005450http://hdl.handle.net/10204/13807TiO2 has excellent photoelectrochemical properties, which makes its suitable for photoanode applications. TiO2 is widely utilized as semiconductor for dyesensitized photoanode owing to its excellent stability and availability. The brookite polymorph of TiO2 has been suggested to demonstrate better photocatalytic properties. In this work, we studied the adsorption of polyenediphenyl-aniline dyes on (TiO2) n = 8, 68 brookite clusters using density functional theory (DFT). We report our results on the UV–Vis absorption spectra of the dyes and dyes adsorbed on TiO2 clusters, adsorption energies of the dyes adsorbed on TiO2 clusters, electronic density of states and projected electronic density of states of the dyes adsorbed on TiO2 complex, and electron density of the main molecular orbitals involved in photoexcitation for dye-sensitized solar cells application. The calculated adsorption energies of D5@(TiO2)68, D7@(TiO2)68, D9@(TiO2)68, and D11@(TiO2)68 are 4.84, 4.78, 4.66 and 4.92 eV, respectively. The results of the adsorption energies are in the order D11@ (TiO2)8 > D9@(TiO2)8 > D7@(TiO2)8 > D5@(TiO2)8 and D11@ (TiO2)68 > D5@ (TiO2)68 > D7@ (TiO2)68 > D9@ (TiO2)68. This implies that D11 dye molecule reacts more strongly with (TiO2)8 and (TiO2)68 brookite clusters than the other corresponding dye molecules.FulltextenDye sensitized solar cellsTiO2 brookite semiconductorPolyene-diphenyl-aniline dyesOptical propertiesFunctional theoryBook Chaptern/a