不同制备方法对BiOCl材料的形貌、结构与光催化性能的影响研究

Influence of Different Synthesis Methods on Structure,Morphology and Photocatalytic Properties of BiOCl Photocatalytic Materials

对比采用溶剂热合成、传统固相合成与溶胶-凝胶合成技术,制备了四方相BiOCl和Nd3+掺杂BiOCl光催化材料。运用X射线粉末衍射(XRD)、扫描电子显微镜(SEM)及紫外-可见吸收光谱(UV-Vis),研究了不同合成方法所制备BiOCl材料的相结构、形貌和紫外-可见光吸收性能;并以甲基橙溶液为模拟废水,研究了不同方法所制备的BiOCl材料的光催化性能。结果表明:溶剂热合成的BiOCl是由纳米片组装成粒径小于1μm微球,紫外-可见吸收边为335 nm;固相合成所得BiOCl结晶度较高,其片状颗粒粒径约为6μm,紫外-可见吸收边为430 nm;溶胶-凝胶合成法制得BiOCl片状颗粒粒径约为3～4μm,紫外-可见吸收边为430 nm。进一步地对比研究了稀土离子Nd3+掺杂前后BiOCl样品的结构、紫外-可见光吸收特性,可以发现,Nd3+掺杂后样品的相结构及形貌均无变化,但吸收边均发生不同程度的红移,以溶胶-凝胶法制得的样品效果最为明显,并具有最优的光催化性能。

The pure tetragonal phase photocatalytic materials BiOCl and Nd3＋ -doped BLOCl were prepared by solvothermal synthesis, solid-phase synthesis and sol-gel synthesis method, respectively. The as-prepared products by different synthesis methods were characterized by X-ray diffraction （XRD）, scanning electron microscopy （ SEM ） and uhraviolet-visible （UV-Vis） absorption spectroscopy, respectively. The photoeatalytie performance of the as-prepared products was evaluated via the UV degradation experiment of the given methyl orange solution. The results indicated that the BiOCI partieles by solvothermal method were composed of numerous BiOCl nanoplates with the dimension of less than 1 μm. The crystalline of BiOCl particles prepared by solid state synthesis was higher than that prepared by sol-gel method, and their plate sizes were about 6 μm and 3 - 4 μm, respectively. Further, their UV-vis absorption boundaries were 335, 430 and 430 nm for the three synthesis methods, respectively. The phase structures and photocatalyst properties of Nd3＋ -doped BiOCl materials were also investigated. The red-shift of the absorption profile was clearly observed for the three kinds of products by different synthesis methods, and the obtained sample by sol-gel method had the best absorption property, which also led to the optimum photocatalys performance from the degradation experiment.