Fabrication of {001}-facet enriched anatase TiO2/TiOF2 heterostructures with controllable morphology for enhanced photocatalytic activity

Abstract The {001}-facet enriched anatase TiO2/TiOF2 heterostructure (TFH) with high photocatalytic activity was successfully synthesized by solvothermal processing of tetrabutyl titanate (TBT) in the presence of HF, acetic acid, and oleic acid solutions. The effects of various reaction parameters on phase composition, morphology/exposed crystal facets, and photoelectric properties of the resulting samples were systematically studied through various characterization methods. Under the preparation conditions of 0.72 g HF, 4 mL TBT and an oleic acid/acetic acid ratio of 80/20, the TFH with dominantly exposed 77.4 % {001}crystal facets can be obtained, showing the best photocatalytic performance. In the degradation of 20 mg/L methylene blue (MB), the photocatalytic efficiency of 0.1 g TFH reached 100 % in 40 min, which was almost equivalent to the activity of P25. The excellent photocatalytic activity was attributed to the synergetic contributions of the formation of heterogeneous structures, large specific surface area, and specific (001) exposed facets.