New reaction pathway induced by the synergistic effects of Bi plasmon and La3+ doping for efficient visible light photocatalytic reaction on BiOCl

Via surface plasmon resonance (SPR) of Bi and La3+ doping techniques, a series of La3+-doped BiOCl microspheres which contained in situ deposited Bi nanoparticles were synthesized by a facile one-step solvothermal pathway. The introduction of semimetal Bi could obviously narrow the band gap (Eg) of BiOCl from 3.33 to 2.91 eV, along with the creation of oxygen vacancies (OVs) on the surface of BiOCl. Besides, the Eg would be further decreased to 2.79 eV and the formation of OVs was largely induced with the doping of La3+. Moreover, La3+ doping could not only increase the specific surface area and reduce the crystallite size of BiOCl, but also as the efficient scavenger to trap photoelectrons. The novel x%La-BiOCl-Bi (x%LBB) composites served as the versatile photocatalysts and exhibited superiority in both oxidation and reduction capacities for degrading Rhodamine B and reducing Cr(VI) although under the 5 W white LED light irradiation, and the 4.5%LBB sample displayed the highest photocatalytic ability, which was extremely meaningful for the practical application. These drastically enhanced visible light photocatalytic capabilities were ascribed to the improved light absorption and the accelerated charge separation inducing by the strong synergistic effects of La3+-doping, OVs and SPR of Bi. The present work may shed new insight into the utilization of rare earth ion doping and low-cost Bi nanoparticles to improve the performance of other photocatalytic materials.