Hierarchical architectures of bismuth molybdate nanosheets onto nickel titanate nanofibers: Facile synthesis and efficient photocatalytic removal of tetracycline hydrochloride

Abstract A huge challenge in the field of pollutant removal is the scarcity of visible-light-driven (VLD) photocatalysts that are efficient, stable, easily recyclable and capable of mineralizing organic pollutants. In this regard, a novel hierarchical architecture of Bi 2 MoO 6 nanosheets onto NiTiO 3 nanofibers for tetracycline hydrochloride (TC) removal was rationally designed and fabricated via a facile approach. In this heterojunction system, highly homogeneous-distributed Bi 2 MoO 6 nanosheets were anchored on electrospun NiTiO 3 nanofibers, endowing the heterojunction with compact interfacial contact. By virtue of the favorable interfacial contact and matched band alignment, promoted suppression of photo-generated electron-hole recombination is achieved in Bi 2 MoO 6 /NiTiO 3 system, as confirmed by photoluminescence measurement. As a result, the heterojunction with Bi 2 MoO 6 /NiTiO 3 molar ratio of 1:1 exhibits an outstanding VLD photocatalytic activity and good stability for tetracycline hydrochloride (TC) degradation. The photodegradation rate constant ( k ) is 26.0, 5.4 or 3.7 folds higher than that of pristine NiTiO 3 , Bi 2 MoO 6 , or the mechanical mixture (20.2 wt% NiTiO 3  + 79.8 wt% Bi 2 MoO 6 ). The holes and superoxide radicals are detected as the dominant active species responsible for TC removal. Moreover, this work reports an efficient VLD photocatalyst for TC removal and will open up new insights into the design of novel fiber-shaped VLD heterojunction photocatalyts for environment remediation.