电子束辐照制备Pd/TiO_2光催化薄膜

Preparation of Pd/TiO_2 photocatalytic films by electron beam irradiation

用电子束辐照浸泡在浓度分别为1×10-5、1×10-4、1×10-3、1×10-2和1×10-1mol/L的PdCl2溶液中的TiO2薄膜,在TiO2薄膜表面形成Pd纳米颗粒。通过X射线衍射(X-ray diffractometry,XRD)、场发射扫描电镜(Field emission scanning electron microscope,FESEM)、X射线光电子能谱(X-ray photoelectron spectroscopy,XPS)和紫外可见(Ultraviolet visible,UV-Vis)吸收光谱对辐照后的Pd/TiO2薄膜进行表征。分析表明,TiO2薄膜表面上沉积了直径20-50nm的颗粒,为面心立方结晶的金属Pd;Pd/TiO2薄膜的UV-Vis光谱吸收边向可见光方向发生了偏移。用甲基橙作为光催化降解反应物,研究了Pd/TiO2薄膜分别在紫外光、可见光作用下的光催化降解效率。结果表明,Pd/TiO2薄膜的光催化能力显著地提高,在紫外光、可见光作用下的光催化效率分别提高了2.25倍和3.4倍。

TiO2 films immerging in PdCl2 solution with [PdCl2] concentration at 10^-5, 10^-4, 10^-3, 10^-2 and 10^-1 mol/L respectively were irradiated by electron beam in order to deposit nano-cluster noble metal Pd. The irradiated films were characterized by XRD, XPS, FMSEM and UV-visible spectrometry. The results show that the Pd clusters with fcc crystal structure were 20-50 nm in diameter on the surface of TiO2 films. Red shift was found in the absorption spectrum of modified Pd/TiO2 films. The photocatalytic capability of the films were tested by degradation of methyl orange （MO） in aqueous solutions under both UV and visible light illumination. The photocatalytic experiments showed that the photocatalytic ability of Pd/TiO2 under both UV and visible light irradiation could be improved dramatically.