铯、锶掺杂钨酸铋的可见光降解酸性品红性能研究

Study on visible light degradation performance ofbismuth tungstate doped by cesium and strontium

采用水热合成了掺杂微量Sr、Cs的钨酸铋光催化剂。利用X射线粉末衍射(XRD)、红外光谱(FT-IR)、扫描电镜(SEM-EDS)、X射线光电子能谱(XPS)、紫外-可见吸收光谱(UV-Vis)及电化学阻抗(EIS)等技术对制得催化剂的表观形貌和晶体结构进行了分析,并通过可见光催化降解酸性品红实验研究光催化剂的催化性能。结果表明,微量的Sr、Cs掺杂未对钨酸铋的物相结构造成影响,掺杂后纳米片的排列更规整,纳米花球直径变小,催化剂比表面积增大。由于Cs^(+)的半径(167 nm)大于Sr^(2+)的半径(118 nm),所以取代Bi^(3+)(103 nm)进入晶格后造成Cs-Bi_(2)WO_(6)的晶格失陪度更高,所以Cs-Bi_(2)WO_(6)的禁带宽度减小更多,吸收光谱红移增大,氧缺陷增多,导致Cs-Bi_(2)WO_(6)光催化降解酸性品红的性能显著高于Sr-Bi_(2)WO_(6)和Bi_(2)WO_(6)。

Bismuth tungstate doped with 1%Sr or Cs is hydrothermally synthesized.XRD,FT-IR,SEM-EDS,XPS,UV-Vis and EIS are used to characterize the morphology and crystal structure of the prepared catalysts,and their catalytic performance are valued through catalytic degradation of acid fuchsin.The results indicate that doping of Sr and Cs does not affect the phase structure of bismuth tungstate.The arrangement of nanosheets becomes more regular after doping,the diameter of nanospheres becomes smaller,and the specific surface area of the catalyst increases.Since the radius of Cs^(+)(167 nm)is greater than that of Sr^(2+)(118 nm),the lattice mismatch of Cs-Bi_(2)WO_(6)is higher than that of Sr-Bi_(2)WO_(6),resulting in the band gap reduces,the absorption shifts to red,and the oxygen deficiency increases.Therefore the photocatalytic degradation performance of Cs-Bi_(2)WO_(6)is significantly higher than those of Sr-Bi_(2)WO_(6)and Bi_(2)WO_(6).