Structural transformation of Sm ³⁺ doped BiVO ₄ with high photocatalytic activity under simulated sun-light

A series of Sm ³⁺ doped BiVO ₄ photocatalysts with high photocatalytic efficiency were successfully synthesized by a microwave hydrothermal method. The effects of Sm ³⁺ doping on the crystal structure, morphology, optical absorption and photocatalytic activity were investigated systematically. From the structural characterization of photocatalysts, the incorporation of Sm ³⁺ into BiVO ₄ could induce the stabilization of tetragonal phase. Meanwhile, the morphology and grain size show an obvious change with doping Sm ³⁺ ions. The Sm ³⁺ doped BiVO ₄ with the optical absorption in UV-light range would accelerate more photogenerated electron-hole pairs, which is in favor of the improvement of photocatalytic activity. The best photocatalytic performance is obtained for the 6at% Sm ³⁺ doped BiVO ₄ , of which the degradation rate of Rhodamine B (RhB) can reach to 96% after 120 min simulated sun-light irradiation. Moreover, the photocurrent results indicate that the obviously enhanced photocatalytic activity of Sm ³⁺ doped BiVO ₄ can be attributed to the efficient separation of photogenerated electron-hole pairs.