Ag_(3)PO4/SnO_(2)异质结催化剂对罗丹明B的光催化降解性能研究

Ag_(3)PO4/SnO_(2)Heterojunction Catalysts for Photocatalytic Degradation of Rhodamine B

以Ag_(3)PO_(4)修饰SnO_(2)空心球制备了一种高效的Ag_(3)PO_(4)/SnO_(2)异质结催化剂用于罗丹明B的光催化降解。与SnO_(2)或Ag_(3)PO_(4)催化剂相比,Ag_(3)PO_(4)/SnO_(2)异质结催化剂的吸收波长发生了红移,禁带宽度降低至2.04 eV。可见光照射6 min后,Ag_(3)PO_(4)/SnO_(2)异质结催化剂对罗丹明B的降解率达到100%,光催化的拟一级反应常数为0.41 min^(-1)。循环3次实验后,降解效率未见明显的降低,表明Ag_(3)PO_(4)/SnO_(2)异质结催化剂具有良好的稳定性。自由基捕获剂实验结果表明,SnO_(2)的加入改变了Ag_(3)PO_(4)催化剂的光催化降解机理。Ag_(3)PO_(4)光催化作用的活性物质是h+,而Ag_(3)PO_(4)/SnO_(2)光催化作用的活性物质是h+和·O_(2)-。

An efficient Ag_(3)PO_(4)/SnO_(2)heterojunction catalyst was synthesized via modifying SnO_(2)hollow spheres with Ag_(3)PO_(4)for the photocatalytic degradation of rhodamine B.Compared with SnO_(2)or Ag_(3)PO_(4)catalysts,the absorption wavelength of Ag_(3)PO_(4)/SnO_(2)heterojunction catalysts was red-shifted.The forbidden band width of Ag_(3)PO_(4)/SnO_(2)heterojunction catalysts was reduced to 2.04 eV.After 6 min of visible light irradiation,the degradation rate of rhodamine B by Ag_(3)PO_(4)/SnO_(2)heterojunction catalyst reached 100%,and the pseudo-first-order reaction constant of photocatalysis was 0.41 min^(-1).After three cycles of experiments,the degradation efficiency did not decrease significantly,indicating that the Ag_(3)PO_(4)/SnO_(2)heterojunction catalyst had good stability.The experimental results of radical scavengers showed that the addition of SnO_(2)changed the photocatalytic degradation mechanism of Ag_(3)PO_(4)catalysts.The active species of Ag_(3)PO_(4)photocatalysis was h+,while the active species of Ag_(3)PO_(4)/SnO_(2)photocatalysis were h+and·O_(2)-.