Co掺杂对MgAl水滑石光催化性能的影响

Effect of Co-doping on Photocatalytic Properties of MgAl Hydrotalcite

采用共沉淀法合成Co Mg Al水滑石光催化剂,采用XRD、UV-vis、TG-DTA和比表面积分析等进行表征。以5 mg/L的罗丹明B溶液作为模拟污染物,考察了Co Mg Al水滑石光催化性能。结果表明:随着Co掺加量的增加,水滑石结晶度下降,对可见光的吸收强度增加,但可见光及365 nm紫外光下的催化性能较弱,只有254 nm紫外光下催化活性较高。适当掺杂Co能够提高催化活性,当Mg∶Al∶Co=3∶0.9∶0.1时制备的Co Mg Al水滑石光催化效果最佳,波长254 nm紫外光照300 min后罗丹明B的降解率达到93.8%。

The CoMgAl-LDHs hydrotalcite photocatalysts were synthesized by coprecipitation method. The samples were characterized by XRD, UV-vis diffuse reflectance, TG-DTA analysis and BET specific surface area. The photocatalytic performance of CoMgAl hydrotalcite for degradation of rhodamine B was investigated. The results show that the crystallinity of hydrotalcite decreases and the absorption intensity for visible light increases with increasing of Co content. The photocatalytic performance of CoMgAl hydrotalcite is lower under irradiation of UV 365 nm and visible light, and is higher under irradiation of UV 254 nm. Doping Co with suitable content can improve the photocatalytic activity, and the CoMgAl hydrotalcite prepared at Mg：Al：Co = 3：0.9：0.1 shows better photocatalytic performance, the degradation rate of rhodamine B can reach 93.8% in 300 min under irradiation of UV 254 nm.