Facile synthesis of Bi-modified Nb-doped oxygen defective BiOCl microflowers with enhanced visible-light-driven photocatalytic performance

Bi-modified Nb-doped oxygen defective BiOCl hierarchical microflowers were synthesized through a facile one-pot solvothermal route. The prepared photocatalysts were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The results indicated that the modified BiOCl appeared as hierarchical microflowers composed of nano sheets. The BiOCl synthesized with Nb/Bi = 1:7 in precursor solutions exhibited the best photocatalytic performance for Rhodamine B (RhB) and Tetracycline (TC) degradation under visible light irradiation. Compared with the BiOCl fabricated through a hydrothermal method, the counterpart with oxygen vacancies (OVs) had a better visible-light-driven photocatalytic activity, and the kinetics constant k for the degradation of RhB increased by 728% (525% for TC). After the modification of Bi0 and Nb5+, the constant k further increased by 134% and 82%, respectively, for the degradation of RhB and TC. This enhanced photocatalytic activity was attributed to both the improved visible light absorption caused by the introduction of OVs and the highly efficient separation of photoexcited carriers resulted from Nb5+ doping and Bi0 deposition. Trapping experiments revealed that the photogenerated hole was the dominating active species. This work provides a new facile strategy for the synthesis of visible-light-driven photocatalysts with high performance.