Magnetic,Photoluminescent and Semiconductive Properties of a Novel 4f-5d Bromide Compound (La6HgsBr26) [4(HgBr2)l (2Br)

An unprecedented 4f-5d material(La6Hg5Br26)[4(HgBr2)](2Br)(1)was syn-thesized by hydrothermal reactions and structurally characterized by single-crystal X-ray diffraction method.Complex 1 crystallizes in the Pbam space group of orthorhombic system with a=13.0980(10),b=13.6650(9),c=28.010(2)?,V=5013.4(6)?^3,Br36Hg9La6,Mr=5515.53,Z=2,Dc=3.613 g/cm^3,μ(MoKα)=29.457 mm^–1 and F(000)=4598.Compound 1 is characteristic of a two-dimensional(2D)layered structure.The photoluminescent measurements with solid-state samples reveal that compound 1 has a strong emission in the green region of light spectrum.It has remarkable CIE chromaticity coordinates of(0.2499,0.3589).A wide optical band gap of 3.41 eV is discovered by the solid-state UV/vis diffuse reflectance spectrum.The variable-temperature magnetic susceptibility obeys the Curie-Weiss law(cm=c/(T–q))with C=2.48 K and a negative Weiss constantθ=–169.07 K as revealed by the magnetic measurements,indicating the existence of an antiferromagnetic interaction in compound 1.     

高性能超级电容器用氧化钌/氮掺杂多孔碳复合材料的研究

采用快速、简便的两步合成法,将RuO_2纳米粒子均匀地负载在氮掺杂多孔碳(NPCs)上,形成RuO_2/NPCs复合材料。首先以壳聚糖为前驱体,SiO_2纳米颗粒为硬模板,制备出比表面积高、呈三维多孔结构的氮掺杂多孔碳材料;在此基础上,将RuO_2纳米粒子通过溶胶-凝胶法均匀负载到NPCs碳骨架的表面和孔隙中,得到RuO_2/NPCs-800复合材料。研究结果表明,RuO_2均匀负载在NPCs的碳骨架上,有效地提高了复合材料的导电性;同时,电化学性能测试显示,RuO_2对复合材料的电化学性能有显著提高,当电流密度为0.5 A/g时,RuO_2/NPCs-800复合材料的比电容高达411.5 F/g,相当于同等条件下NPCs(123.9 F/g)的3.3倍;同时显示较好的循环稳定性,在5 A/g电流密度下,5000次循环后,只有6.3%比电容降低。     

原位MgO模板法制备酚醛树脂基分级多孔碳材料及其特性研究

通过简单、经济且高效的原位MgO模板法制备分级多孔碳材料。在该方法中,以酚醛树脂作为碳源,柠檬酸镁为模板,通过热解聚合物和模板前驱体的混合物并结合KOH活化来制备有序分级多孔碳材料(APRC)。由于聚合物、MgO和KOH的协同作用,所制备的APRC具有独特的均衡分级多孔结构特征,包含大量微孔、中孔和大孔。此外,APRC具有较高比表面积和良好导电性,独特的微结构赋予APRC优异的电容性能,在6 mol/L KOH水溶液中,扫描速度为5 mV/s,APRC电极具有214 F/g高的比电容,同时具有高的倍率性能(扫描速度增加到100 mV/s时,比电容保持率为75%)和优异的循环耐久性(扫描速度为50 mV/s,经5000次循环电容保持率为95.1%)。这些结果表明所制备的分级多孔碳材料在高性能双电层电容器中具有潜在应用价值。