Fe掺杂对水热合成In2O3结构与光催化性能的影响

Effect of Fe-doping on the microstructure and photocatalytic properties of In2O3 prepared by hydrothermal method

通过水热合成法制备了不同Fe掺杂浓度的Fe-In2O3复合材料,采用扫描电镜、元素能谱、X射线衍射、X射线光电子能谱、红外光谱、紫外-可见漫反射光谱等技术分析了样品的形貌与微观结构,并以罗丹明B为目标降解物测试了其光催化性能.结果表明,随Fe掺杂量的增加,In2O3晶粒的形貌由短纤维构成的不规则厚片状向纤细的薄片状变化,最终呈现花朵状.表面形貌的改变使样品的吸附性增强,并导致OH键(H2O)的振动加强,样品形成了新的化学键Fe—O—In,使晶体衍射峰的峰位发生偏移.Fe掺杂也抑制了In2O3晶粒的长大,同时随Fe含量的增加,In2O3的光吸收范围逐渐向可见光方向移动.最终发现Fe掺杂可以明显提高In2O3的光催化性能,在紫外光照射下其对罗丹明B的降解率可达96%.光催化降解罗丹明B的过程符合一级反应动力学方程,活性物种捕获实验证明空穴和超氧自由基是光催化体系中的主要活性物种.

In this work,Fe-In 2O 3 composites with different Fe-doping concentrations were prepared by hydrothermal synthesis.The morphology and structure of the materials were characterized by SEM,EDS,XRD,XPS,FT-IR and UV-Vis DRS, then the Rhodamine-B(RhB) was used as the target to test their photocatalytic performance.The results showed that as the increase of Fe content,the morphology of Fe-In 2O 3 grains can be changed from thick flakes which consist of short fibers to thin flakes,finally,it forms a flower-like shape.The refinement of the surface morphology leads to the enhancement of the adsorption properties which has been evidenced by the increase of OH groups and a new chemical bond Fe-O-In is formed in the composites,which leads to the peak position of the crystal diffraction shifts.The crystal growth of In 2O 3 has been hindered by the doping of Fe,while the light absorption range is also gradually shifted toward the visible light as the Fe content increases in the composie.It is found that the photocatalytic performance of In 2O 3 has been obviously improved by Fe-doping,and the degradation rate of RhB can reach to 96% under the ultraviolet light irradiation.The degradation of RhB can be described by the first-order kinetics equation.Meanwhile,the capture test of active species proves that holes and superoxide radicals play a major role in the photocatalytic degradation.