溶胶-凝胶法制备Pt2+掺杂Bi2O3及光催化性能研究

用溶胶-凝胶法制备了Pt2+掺杂的Bi2O3光催化剂(Pt/Bi原子比分别为1/100、2/100、3/100和4/100),以甲基橙为模拟有机污染对催化剂的光催化性能进行了考察。光催化剂用BET、XRD、XPS和紫外-可见漫反射进行了表征,结果表明Pt/Bi原子比为3/100时催化剂的比表面最高;经500℃焙烧后光催化剂晶型为α-Bi2O3;掺杂Pt2+后Bi2O3在可见光区的吸收增强;掺杂Pt2+后Bi 4f7/2和O 1s结合能均向低能端偏移,催化性能测试结果表明Pt/Bi原子比为3/100时的催化剂活性最高。增加的比表面、对可见光响应增强和结合能向低能端偏移均有利于提高Bi2O3光催化活性。

Photocatalytic Activity of Pt2+-doped Bi2O3 Prepared by Sol-gel Method

Bi2O3 and Pt2+-doped Bi2O3 photocatalysts with different molar ratios of Pt/Bi(1/100,2/100,3/100,4/100) were prepared by a sol-gel method.The structural properties of the photocatalysts prepared were studied by BET surface area,X-ray diffraction(XRD),UV-Vis diffuse reflectance(DRS) and X-ray photoelectron spectroscopic(XPS) techniques.The results show that the Bi2O3 catalyst with 3/100(Pt/Bi) has the highest BET surface area,and pore volume and the smallest pore size.The XRD patterns of the Pt2+-doped Bi2O3 catalysts calcined at 773 K show only the characteristic peaks of α-Bi2O3 phase.The absorbance of Pt2+-doped Bi2O3 in visible region increases with the increasing of the amount of Pt2+.XPS results reveal that the binding energies of Bi 4f7/2 and O 1s of Pt2+-doped Bi2O3 shift to lower value.Among all of the photocatalysts prepared,the Pt2+-doped Bi2O3 catalyst with 3/100(Pt/Bi) possesses the best photocatalytic activity.The results of further experiments show that the specific surface area,UV-Vis diffuse reflectance and the binding energy all play an important role in promotion of photocatalytic activity of doped Bi2O3 nanostructure.