Rational design of efficient visible-light photocatalysts (1D@2D/0D) ZnO@Ni-doped BiOBr/Bi heterojunction: Considerations on hierarchical structures, doping and SPR effect

Simultaneously integrating heterogeneous interface, element doping, and metal decorating was a promising strategy to promote the visible-light-driven photocatalytic activity. Herein, we demonstrated a facile solvothermal route for Ni-doped BiOBr/Bi0 with ZnO 3D hierarchical heterojunction (denoted as [email protected]/Bi-Ni). The optimal photocatalysts of [email protected]/Bi-Ni sample presented a remarkable catalytic performance of high concentrations of tetracycline solution (40 mg/L) than those of the [email protected]/Bi, [email protected], BOB and ZnO photocatalysts toward the visible-light-driven degradation. The enhanced photocatalytic mechanism can be proposed as follows: (i) 3D hierarchical heterojunction provided more active sites and accelerated the separation of charge carriers for photocatalytic TC; (ii) formation of oxygen vacancies on the surface over [email protected]/Bi-Ni by in-situ reduction of Bi0 and Ni doping could serve as the active sites for oxygen activation to adsorb free O2 and generate more superoxide radicals; (iii) SPR effect of Bi metal were beneficial to carrier separation and also act as the active site to trap O2 molecules. This work clarified the role of unique morphologies, surface plasmonic resonance (SPR) effect of metal Bi, and Ni doping in [email protected]/Bi-Ni, and its photocatalytic reaction mechanism was proposed by a series of experiments, characterization and DFT calculations, arousing a new perspective to design hierarchical heterojunction photocatalysts.