纳米纤维基催化材料的制备及其在环境领域中的应用研究进展

纳米粒子催化剂具有优异的催化活性，但在使用时其易团聚且回收较为困难。鉴于此，以纳米纤维为载体，将纳米粒子催化剂负载于纳米纤维上制得纳米纤维基催化材料，从而有效解决了纳米粒子催化剂的回收难题。为更好了解纳米纤维基催化材料的制备及应用研究进展，综述了近年来纳米纤维基催化材料的制备方法和工艺流程，介绍了纳米纤维基催化材料在催化染料降解、有机物降解、重金属离子还原等领域的应用研究进展。最后指出：纳米纤维基催化材料具有催化活性高、催化剂易回收等优点，但仍存在力学性能差和制备效率低的缺点，尚无法满足大规模实际应用；为满足实际应用，提高纳米纤维基催化材料力学性能，寻求批量化制备工艺，是未来研究的重点。

Research progress of preparation of nanofiber-supported catalysts and application thereof in environmental protection

Significance Nano-sized catalysts show higher catalytic activity than bulk analogues by virue of their larger specific surface area. Therefore, nano-sized catalysts have been widely used in the field of catalysis research. However, nano-sized catalysts tend to agglomerate during the application, which leads to the formation of large particles and a huge reduction in catalytic activity. Meanwhile, the recycling of nano-sized catalysts is difficult. These challenges all restrict the application of nano-sized catalysts. In order to solve these problems, some efforts have been made, such as surface modification, and immobilization of the nano-sized catalysts on supports. Among the various supports employed, the nanofibers have attracted much attention by virue of their larger specific surface area and nanoscale diameter. The larger specific surface area of nanofibers leads to an increase in the catalytic activity of nanofiber-supported catalysts as more active sites are available and accessible by reactants in the catalysis process. Moreover, the recovery and reuse of nanofiber-supported catalysts are simple. Hence, the nanofiber-supported catalysts show potential applications in the field of catalysis.Progress The recent studies about the preparation of nanofiber-supported catalysts and their application in environmental remediation are reviewed. As a general method for preparing nanofibers, electrospinning technology has been known to be able to prepare nanofibers with various compositions and structures. The methods involving electrospinning technology for preparing the nanofiber-supported catalysts could be divided into two ways. One method is coated by an electrospinning process, in which the nano-sized catalysts or catalyst precursors are dispersed into an electrospinning solution followed by the electrospinning process. If the catalyst precursors are added to the electrospinning solution, a post treatment is necessary after the electrospinning process to convert catalyst precursors into nano-sized catalysts. The other method is to deposit the nano-sized catalysts on the surface of nanofiber after electrospinning process. Though the coating method is simple, it is difficult to achieve a homogeneous dispersion of nano-sized catalysts in nanofibers. While the precursor electrospinning deposition method shows more advantages for preparing nanofiber-supported catalysts with quite uniform distribution of the nano-sized catalysts on nanofiber surface. The simplicity of recovery and the higher catalytic activity of nanofiber-supported catalysts makes them economical and environmentally friendly in the application of dye degradation, organic matter degradation, and heavy metal ion reduction, etc.Conclusion and Prospect According to the reported research, nanofiber-supported catalysts have the advantages of high catalytic activity and recyclability. Thus, nanofiber-supported catalysts have great potential in catalytic applications. However, they still has the disadvantages of poor mechanical properties and low preparation efficiency, which cannot meet the requirement of practical applications. Therefore, some efforts can be made from the following aspects in future research. 1) In view of practical applications, nanofiber-supported catalysts with fine mechanical properties have huge advantages. Some efforts should be made to improve the mechanical properties, such as tailoring the structure by regulating the electrospinning process and using the substrates with excellent mechanical properties as the nanofiber receiver. 2) The large-scale fabrication and commercial application of nanofiber-supported catalysts are still a huge challenge. Therefore, it is necessary to explore the electrospinning process using green solvent and have low cost and high efficiency for fabricating nanofiber-supported catalysts. 3) The catalytic activity of nanofiber-supported catalysts should be improved by optimizing the structure and surface composition of nanofibers as it is highly dependent on the active sites of nanofiber-supported catalysts. Except for the metal-based catalysts, other catalysts should be combined with nanofibers to expand the applications of nanofiber-supported catalysts.