Noble Metal Modified TiO2 Hierarchically Structured Microspheres with Enhanced Photocatalytic Activity

Anatase TiO2 hierarchically structured microspheres with co-exposed {001}/{101} facets were prepared by a facile one-pot hydrothermal method. The influences of reaction temperature on the morphology and crystallization of microspheres were investigated systematically. The obtained microspheres possessed better morphology and crystallization when the reaction temperature was 160 °C. Different noble metals (Au, Ag, Cu, Pt, Pd) were used for the microspheres modification, and the experimental results exhibited that the photocatalytic activities of the noble metal modified microspheres were enhanced obviously, especially for the Pt-modified sample (TPt), which showed the highest photocatalytic activity in degradation of tetracycline hydrochloride (the TPt sample showed the largest improvement, i.e., the activity reached 1.47 times higher than that of the bare sample) and hydrogen production (the largest improvement was also observed for the TPt sample, i.e., the activity was more than 30 times as the bare sample, reaching more than 300 μmol·g−1·h−1). Finally, a photocatalytic reaction mechanism involving the synergy of co-exposed {001}/{101} crystal facets with noble metals was proposed according to the as-obtained experimental results.