氮化硼纳米片的制备及其可调控磁性的研究

Hexagonal boron nitride nanosheets (BNNSs) are the isoelectric analogue of graphene. Compared with graphene, BNNSs has many peculiar properties, including high temperature stability, anti-oxidation ability, corrosion-resistance, broad bandgap, and so on. These unique features lead to BNNSs having a promising application. However, compared to the preparation of graphene, the methods to prepare BNNSs are fewer and less effective. In addition, it is still a great challenge to improve the properties of BNNSs via functionalization or doping, which leads to extend their application fields. In order to solve above problems, we plan to use a chemical exfoliation method to obtain large size and few-layer BNNSs with high yield，and to implement the functionalization of BNNSs preliminary. Moreover, we have developed an innovative approach for the chemical functionalization of BNNSs. We have reported a one-step route to exfoliate and fluorinate the BNNSs from hexagonal boron nitride (h-BN) powder, and initially verified that the as-prepared fluorinated BNNSs (F-BNNSs) exhibit ferromagnetic characteristics. On this basis, we will further study the tunable magnetic properties of the as-prepared F-BNNSs, which would establish a foundation to have good potential applications for spintronic devices.

氮化硼纳米片和石墨烯的结构类似，但与石墨烯相比，氮化硼纳米片具有更好的耐高温、更高的抗氧化性、更强的抗化学腐蚀性和宽带隙等优异的性能。这些优点使得氮化硼纳米片在许多方面具有很好的应用前景。但是，相对于石墨烯，氮化硼纳米片的制备方法不是很多，而且产率不高。目前，如何通过功能化或掺杂等手段来提高氮化硼纳米片的应用性能也是一个极具挑战性的问题。为了解决上述问题，本课题拟通过化学剥离法将六方氮化硼粉末剥离成较大尺寸和少层的氮化硼纳米片，并提高纳米片的产率；进而初步实现氮化硼纳米片的功能化。另外，我们在氮化硼纳米片的功能化研究方面取得了重要的创新性成果。我们利用一步氟化剥离法将六方氮化硼粉末剥离成氟化氮化硼纳米片，首次证实了氟化氮化硼纳米片具有铁磁性；在此基础上，我们进一步研究氟化氮化硼纳米片的磁性的可调控性，为其在电子自旋器件研究领域奠定基础。

氮化硼纳米片和石墨烯的结构类似，但与石墨烯相比，氮化硼纳米片具有更好的耐高温、更高的抗氧化性、更强的抗化学腐蚀性和宽带隙等优异的性能。这些优点使得氮化硼纳米片在许多方面具有很好的应用前景。目前，氮化硼纳米片的有效制备方法不是很多，从而限制了氮化硼纳米片功能化的研究。为了解决上述问题，本项目成功利用了尿素、碳酸氢钠、碳酸氢铵和乙二胺等化学试剂将氮化硼粉末剥离成大尺寸和少层的氮化硼纳米片，并且有较高的产率。利用所得氮化硼纳米片进行功能化研究，制备出了氮化硼纳米片/聚乙烯醇薄膜复合材料和氮化硼纳米片/聚乙二醇复合材料。通过热重分析仪表征发现，氮化硼纳米片能够提高聚乙烯醇和聚乙二醇高分子材料的热稳定性。通过紫外-可见分光光度计表征，所制备的氮化硼纳米片/聚乙烯醇薄膜复合材料和氮化硼纳米片/聚乙二醇复合材料在深紫外区具有一定的吸收能力。本项目还利用一步氟化剥离法将六方氮化硼粉末剥离成氟化氮化硼纳米片，并且证实了其具有铁磁性；通过系统优化反应条件，使氟化氮化硼纳米片的磁化强度提高，为其在稀磁半导体材料研究领域奠定了实验基础。