Internal electric field and oxygen vacancies synergistically enhancing luminescence properties of Eu3+-doped bismuth oxychloride microcrystals

Abstract Lanthanide-doped BiOCl have attracted extraordinary attention due to their fascinating luminescence properties. Rational structural design is indispensable for exploring the potential application of lanthanide-doped BiOCl. In this work, BiOCl:Eu3+ microcrystals with multiform morphologies were prepared by a simple solvothermal method. The thickness and morphologies of the samples could be tuned just by changing bismuth source and reaction solvent, include 1D nanorods (NRs), 2D nanosheets (NPs), and 3D hierarchical porous structures (HPs). Under the excitation of 313 nm, all the samples showed a strong far-red emission (698 nm) of Eu3+ ions and obviously enhanced with increasing dimensionality. The enhanced luminescence was attributed to the synergic effect of the internal electric field and oxygen vacancies. To verify this concept, the photocatalytic properties of the samples are characterized. As a consequence, BiOCl:Eu3+ 3D HPs displayed the best photocatalytic activity for the degradation of RhB under visible light illumination. This work further uncovered the intrinsic reasons for the morphology dependence of the luminescence performance of BiOCl:Ln3+ microcrystals.