Wang Huiya, Zhang Yanlin, Wang Qiuyue, Jia Chaowei, Cai Pan, Chen Gang, Dong Chengjun, Guan Hongtao
School of Materials Science and Engineering, Yunnan University Kunming 650091 P. R. China
Yunnan Province Key Lab of Micro-Nano Materials and Technology, Yunnan University Kunming 650091 P. R. China.
RSC Adv. 2019 Mar 19;9(16):9126-9135. doi: 10.1039/c9ra00466a. eCollection 2019 Mar 15.
Electromagnetic absorption materials have gained increasing attention. In this study, we report NiO decorated biomass porous carbon derived from pine nut shells as a promising microwave absorbing material by a facile strategy. The NiO/biomass porous carbon (BPC) is thermally converted from Ni(OH)/BPC with BPC as the base for precipitation. All products were characterized by XRD, Raman, and SEM techniques, which reveals that the NiO nanoflakes were uniformly self-assembled on the surface of the activated carbon. Compared with counterparts of pure Ni(OH) and Ni(OH)/BPC, a large reflection loss peak of -33.8 dB at 16.4 GHz is achieved for the NiO/BPC composites, and the absorption bandwidth less than -10 dB can reach up to about 6.7 GHz (from 11.3 to 18.0 GHz) with a thickness of 8 mm. The enhanced microwave absorption properties originate from the electric/dielectric polarization and the unique NiO decorated BPC structures. The expanded interfaces, such as NiO-NiO, Ni-BPC and NiO-paraffin interfaces in the complicated porous composites, could boost the interfacial polarization as well as related relaxation which results in enhanced dielectric loss and electromagnetic absorbing properties. In addition, NiO/BPC nanocomposites exhibit comparatively better matching of permittivity and permeability. It is expected that our present investigation could provide a new possibility for biomass based fabrication of potential microwave absorbing materials.
电磁吸收材料已受到越来越多的关注。在本研究中，我们报道了一种通过简便策略制备的以松子壳为原料的NiO修饰生物质多孔碳，它是一种很有前景的微波吸收材料。NiO/生物质多孔碳（BPC）由Ni(OH)/BPC热转化而来，其中BPC作为沉淀的基底。所有产物通过XRD、拉曼和SEM技术进行表征，结果表明NiO纳米片均匀地自组装在活性炭表面。与纯Ni(OH)和Ni(OH)/BPC的对应物相比，NiO/BPC复合材料在16.4 GHz处实现了-33.8 dB的大反射损耗峰，在厚度为8 mm时，小于-10 dB的吸收带宽可达约6.7 GHz（从11.3到18.0 GHz）。增强的微波吸收性能源于电/介电极化以及独特的NiO修饰BPC结构。复杂多孔复合材料中的扩展界面，如NiO-NiO、Ni-BPC和NiO-石蜡界面，可以促进界面极化以及相关的弛豫，从而导致介电损耗和电磁吸收性能增强。此外，NiO/BPC纳米复合材料表现出相对较好的介电常数和磁导率匹配。预计我们目前的研究可为基于生物质制备潜在的微波吸收材料提供新途径。
