3D hierarchical anatase TiO2 superstructures constructed by “nanobricks” built nanosheets with exposed {001} facets: facile synthesis, formation mechanism and superior photocatalytic activity

Abstract

Exploring anatase TiO₂ with a superior photocatalytic activity is worthwhile as well as challenging. 3D hierarchical anatase TiO₂ with a high percentage of exposed {001} facets has been successfully synthesized through a simple one-pot solvothermal strategy in the presence of ammonium fluoride and ethylene glycol solution. It was found that both NH₄F and ethylene glycol played an essential role in directing a 3D hierarchical structure with exposed {001} facets. Characterization by SEM, TEM, XRD, and TG endorsed a plausible proposed formation mechanism of “nucleation–aggregation–recrystallization”. The product was proven to exhibit superior photocatalytic activity under the synergistic effect of improved light-harvesting ability and higher reactivity of exposed {001} facets.