Abstract: A semiconductor-absorber composite comprises a mesoporous titania particle, halogen atoms disposed on a surface of the mesoporous titania particle, and photoactive perovskite in physical contact with at least a portion of the surface of the mesoporous titania particle.

Abstract: The present disclosure relates to methods of preparing sols of titanium dioxide nanoparticles that are photoactive, neutral, and in a substantially concentrated form. The methods particularly provide for concentrated sols in light of washing and dewatering under low cation concentrations and utilizing rapid peptizing through addition of the filter case to the peptizing agent. Concentrated acid may be utilized to maintain high TiO2 concentration while still avoiding precipitation of the colloidal TiO2. Concentrated photoactive, neutral titanium dioxide sols are also provided as well as compositions thereof and photoactive coatings formed therewith.

Abstract: The disclosure provides a metal oxide-doped titanium dioxide (TiO2) composition, with a solid phase including TiO2 and one or more metal oxides and a liquid phase. Methods of preparing such doped compositions are also provided. The doped compositions disclosed herein can exhibit adsorption and photocatalytic properties, particularly in the context of treating gas streams containing H2S gas (e.g., to reduce atmospheric pollution).