Synthesis of B-Er co-doped BiVO4 photocatalyst and its photodegradation of methyl orange under visible-light irradiation

Er-B co-doped BiVO4 visible-light-driven photocatalysts had been synthesized by citric acid complex method. The samples were characterized by XRD, SEM, EDS and UV-vis DRS analyses and the photocatalytic activity was investigated by photocatalytic degradation of methyl orange (MO). The XRD patterns show that doping does not change the crystal structure of BiVO4 and all samples are monoclinic structure. But the crystal sizes of all Er-B co-doped BiVO4 are smaller than those of B-doped BiVO4 and pure BiVO4. The UV-vis DRS analyses show that Er-B co-doping leads to higher light absorption intensity and narrower band gap compared with B-doped BiVO4 and pure BiVO4. And the doped Er (III) ions can help the separation of photogenerated electrons. Compared with BiVO4 and B-BiVO4, the photocatalytic activity of Er-B co-doped BiVO4 is remarkable improved due to the synergistic effects of the co-doped ions. The degradation rate of MO in 60 min is 96.62% when B and Er doping content is 4% and 1%, respectively (molar ratio), which is much higher than that of pure BiVO4 (20%) and B-BiVO4(37%).