Facile in-situ construction of Z-scheme Bi6O5(OH)3(NO3)5·3H2O/Bi5O7I binary heterojunction composites for superior photocatalytic degradation of diverse persistent organic pollutants in water

Abstract

Constructing efficient heterojunction photocatalysts via facile synthetic strategies is attractive from the viewpoints of improving photocatalytic efficiency and energy saving. Herein, a series of novel Bi6O5(OH)3(NO3)5·3H2O/Bi5O7I (BBN/BOI) Z-scheme binary heterojunction composites were successfully prepared by a facile in-situ growth of Bi6O5(OH)3(NO3)5·3H2O nanoplates on the surface of Bi5O7I as substrate material. The structural features, morphology and optical properties of the fabricated samples were investigated by various physicochemical methods. The BBN/BOI composites exhibited enhanced photocatalytic superiority in comparison with Bi6O5(OH)3(NO3)5·3H2O and Bi5O7I. The sample BBN/BOI-1 prepared with a Bi(NO3)3·5H2O/Bi5O7I feeding molar ratio of 1:1 displayed the best photocatalytic performance for 2-sec-butyl-4,6-dinitrophenol (DNBP) and Rhodamine B (RhB) degradation under simulated solar light illumination with good recycling characteristics. The Z-scheme charge transfer mechanism in BBN/BOI composites can not only facilitate the separation and migration of photoinduced electron-hole pairs but also retain strong redox reaction capacity, which contributes to promote the generation of h+ and •O2− as major active species responsible for the photocatalytic degradation of organic pollutants. The structural stability and photocatalytic activity of BBN/BOI system verifies its great potential for applicability in wastewater treatment.