Realizing High Photocatalytic Performance of NaBiS2 Nanopowders via the Introduction of Rare-Earth Elements

Rare earth (RE) elements (RE=Sm, Nd) added NaBiS2 nanoparticles are successfully synthesized by a facile one pot growth method. The photocatalytic performance of all samples are evaluated by the degradation of Rhodamine B (RhB) under the visible light irradiation. The results show that the existence of amorphous phase and RE ions lead to both act as electron traps to capture the electron and promote the separation of photoinduced charge carriers. In addition, the midgap energy levels induced by RE ions lead to further energy transfer in the up-conversion process to enhance the absorption of photons and boost the lifetime of photocarriers to improve the photocatalytic performance. The NaBiS2 sample with 5%Nd and 5%Sm possess the best catalytic activity in which the degradation efficiency of RhB is beyond 90% under the visible light irradiation for 60min. Furthermore, the photocatalytic mechanism of NaBiS2 is discussed in detail.