高结晶度镍铝水滑石的制备及其电化学行为研究

水滑石(Hydrotalcite,简称HT)是一类层状结构的阴离子粘土,它具有碱性特征、微孔结构、记忆效应及金属离子的同晶可取代性和层间阴离子的可交换性.此外,由于它具有材料廉价易得,独特的离子交换性能,很好的热和化学稳定性等特点,使其在电分析方面作为安培传感器~([1])、电位传感器~([2])、生物传感器~([3])以及作为超级电容器的电极活性材料~([4-6])刮都有潜在应用价值.     

Nitrogen and Boron Co-Doped Carbon Nanotubes Embedded with Nickel Nanoparticles as Highly Efficient Electromagnetic Wave Absorbing Materials

Due to the limitations of impedance matching and attenuation matching,carbon nanotubes(CNTs)employed alone have a weak capacity to attenuate electromagnetic wave(EMW)energy.In this work,B and N co-doped CNTs with embedded Ni nanoparticles(Ni@BNCNTs)are fabricated via an in situ doping method.Compared with a sample without B doping,Ni@BNCNTs demonstrate a superior EMW absorption performance,with all minimum reflection loss values below?20 dB,even at a matching thickness of 1.5 mm.The experimental and theoretical calculation results demonstrate that B doping increases conduction and polarization relaxation losses,as well as the impedance matching characteristic,which is responsible for the enhanced EMW absorption performance of Ni@BNCNTs.     

阴离子柱撑磁性镍铝水滑石的制备及表征

将磁性基质与镍铝类水滑石组装制备磁性镍铝水滑石。研究了磁性基质含量、焙烧温度对水滑石磁学性能及结构的影响。并采用SEM、XRD、FT-IR、DSC-TG及VSM(vibrating sample magnetometer)等测试技术对制备的水滑石的结构和磁学性能进行了表征。结果表明,磁性基质的引入赋予镍铝类水滑石以超顺磁性,磁性基质含量对样品的磁性能起决定性作用,磁性镍铝水滑石的比饱和磁化强度随磁性基质含量的增加而增加;XRD分析结果表明,磁性基质的引入没有改变水滑石的典型层状结构且随着磁性基质含量的增多,磁性镍铝水滑石的特征衍射峰的衍射强度有所降低,n(Ni2 )/n(Fe2 )达到20时,XRD谱图中开始出现Fe3O4晶相的衍射峰;前驱体经1073K焙烧后出现尖晶石晶相;DSC-TG分析结果表明,磁性基质的引入没有改变水滑石2个阶段吸热的特征,这与XRD的检测结果一致。