Synthesis, Characterization and Photocatalytic Performance of SnS Nanofibers and SnSe Nanofibers Derived from the Electrospinning-made SnO2 Nanofibers

SnO2 nanofibers were fabricated by calcination of the electrospun PVP/SnCl4 composite nanofibers. For the first time, SnS nanofibers and SnSe nanofibers were successfully synthesized by double-crucible sulfurization and selenidation methods via inheriting the morphology of SnO2 nanofibers used as precursors, respectively. X-ray diffraction (XRD) analysis shows SnS nanofibers and SnSe nanofibers are respectively pure orthorhombic phase with space group of Pbnm and Cmcm. Scanning electron microscope (SEM) observation indicates that the diameters of SnS nanofibers and SnSe nanofibers are respectively 140.54±12.80 nm and 96.52±14.17 nm under the 95 % confidence level. The photocatalytic activities of samples were studied by using rhodamine B (Rh B) as degradation agent. When SnS or SnSe nanofibers are employed as the photocatalysts, the respective degradation rates of Rh B solution under the ultraviolet light irradiation after 200 min irradiation are 92.55 % and 92.86 %. The photocatalytic mechanism and formation process of SnS and SnSe nanofibers are also provided. More importantly, this preparation technique is of universal significance to prepare other metal chalcogenides nanofibers.

本研究通过煅烧静电纺丝制备的聚乙烯吡咯烷酮（Polyvinylpyrrolidone, PVP）/四氯化锡（SnCl₄）复合纳米纤维，成功制备得到二氧化锡（SnO₂）纳米纤维。首次以该二氧化锡纳米纤维作为前驱体，分别通过双坩埚硫化法与硒化法，保留其原始形貌并成功合成硫化锡（SnS）纳米纤维与硒化锡（SnSe）纳米纤维。X射线衍射（XRD）分析结果表明，硫化锡纳米纤维与硒化锡纳米纤维均为纯相正交晶型，其空间群分别为Pbnm与Cmcm。扫描电子显微镜（SEM）观测显示，在95%置信水平下，硫化锡纳米纤维与硒化锡纳米纤维的直径分别为140.54±12.80 nm与96.52±14.17 nm。本研究以罗丹明B（Rhodamine B, Rh B）为降解底物，考察了所制备样品的光催化性能：当以硫化锡纳米纤维或硒化锡纳米纤维作为光催化剂时，紫外光照射200分钟后，罗丹明B溶液的降解率分别可达92.55%与92.86%。本研究同时阐明了硫化锡与硒化锡纳米纤维的光催化机理与生长过程。更为重要的是，该制备技术对于拓展制备其他金属硫族化合物纳米纤维具有普适性意义。