Sb_2O_3/α-Fe_2O_3纳米异质结的制备及其光催化性能

PREPARATION AND PHOTOCATALYSIS OF SB_2O_3/ Α-FE_2O_3 HETEROJUNCTION

以Fe(NO3)3·9H2O和Sb Cl3为原料,采用水热法和浸渍法制备了Sb2O3/α-Fe2O3纳米异质结复合可见光催化剂,并用X射线衍射(XRD)、扫描电子显微镜(SEM)、X射线光电子能谱(XPS)和紫外可见漫反射光谱(UVVis DRS)等测试手段表征了试样的结构和性能。结果表明:Sb2O3与α-Fe2O3的复合使α-Fe2O3吸收带边红移,在可见光区的吸收增强;Sb2O3只存在于α-Fe2O3的表面,未改变α-Fe2O3的晶体结构;二者形成的异质结,能高效转移光生载流子,并实现电子-空穴的高效分离;以甲基橙为目标降解物考察了催化剂的可见光催化降解性能,结果显示,Sb2O3/α-Fe2O3的可见光催化活性优于纯α-Fe2O3;当Sb2O3的复合含量为1.5%时,光催化活性最佳。

Sb2O3/α-Fe2O3 heterojunction photocatalysts are synthesized by hydrothermal and impregnation method using Fe(NO3)3 ·9H2O and SbCl3as starting materials. The as-prepared samples are characterized by X-ray diffraction (XRD), scanning electron microscopy(SEM), X-ray photoelectron spectroscopy (XPS), UV-Vis diffuse reflectance spectra ( UV-Vis DRS). The results show that Sb2 O3 exists only on the surface, and has no effect on the crystal structure of α-Fe2 O3;The formation of Sb2 O3/α-Fe2O3 heterojunction can effectively promote the separation efficiency of photo-induced electron-hole pair and the transfer probability of charge carrier and result in an increase in visible-light photocatalytic activity. The photocatalytic activities of samples are examined by monitoring the degradation of methyl orange in an aqueous solution under solar light radiation. Results show that the photocatalytic ac-tivity of Sb2 O3/α-Fe2O3 heterojunction photocatalysts is much better than that of pure α-Fe2O3 . The optimal content of Sb2O3 is found 1. 5w%.