Facile synthesis of BiOCl/g-C3N4 heterojunction via in situ hydrolysis of Bi nanospheres: a high-efficiency visible-light-driven photocatalyst

Abstract

BiOCl/g-C3N4 (BC) heterojunctions were constructed successfully through a novel in situ hydrolysis method by taking metallic Bi nanospheres as Bi source. The TEM and HRTEM images showed the heterogeneous nanostructures at the interface between BiOCl and g-C3N4. The combination of BiOCl and g-C3N4 enlarged the light adsorption range of the BC heterojunctions, which extended to visible region. Besides, the contact of the two semiconductors at the heterointerfaces improved the separation efficiency of photoinduced charge carriers, thus endowing the BC samples with superior visible-light-driven (VLD) photocatalytic performance in degrading organic pollutants. Notably, the BC12% sample exhibited the optimized photocatalytic activity in which 97.3% of RhB was decomposed within 30 min, achieving 13.87- and 4.26-times improvement than the bare BiOCl and pristine g-C3N4, respectively. Moreover, the trapping experiments revealed that .O2− and h+ were the dominant active species during the degradation processes of RhB. Meanwhile, the possible degradation pathway of RhB was proposed on the basis of the intermediate products detected by LC–MS, and the appearance photocatalytic mechanisms were also discussed in detail. As an original strategy to obtain samples with highly dispersed heterointerface, this work provides a facile route for the surface modification of g-C3N4 via a facile hydrolysis process of metallic particles to form heterostructures and very promising for practical application.