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A novel 1-D Cd(Ⅱ) coordination polymer, [Cd(p-BDOA)·2H2O]n(I) ( p-BDOA2-=benzene-1,4-dioxyacetate dianion) has been synthesized and characterized by elemental analysis, IR, PL, TG and X-ray single crystal diffraction. The Crystal crystallizes in monoclinic system, the space group is C2/c, with the crystal cell parameters a=1.175 1(1) nm, b=0.551 0(1) nm, c=1.827 7(2) nm, β=96.14(2)°, and V=1.176 6(3) nm3,, Mr=372.60, R=0.045 9, wR=0.127 9. The Cd(Ⅱ) ion has a trigonal prism coordination configuration that defined by four carboxyl O atoms from two different p-BDOA2- ligands and two water molecules. Adjacent Cd(Ⅱ) ions are linked by carboxylate groups with the bidentate coordination mode, giving rise to a chain structure with the adjacent Cd…Cd distance of 1.526 3(5) nm. Furthermore, such chains are linked by hydrogen bonds to form supramolecular network. The results of PL and TG show that the complex exhibits intense fluorescent emissions and its chain skeleton is thermally stable up to 419 K. CCDC: 220443. 相似文献
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将三肽Gly-Gly-His(GGH)共价键合到MPA修饰的微悬臂梁表面,研究了肽与Cu2+的相互作用过程.研究发现,在Cu2+浓度较高时,Cu2+能快速与不同肽链上的羧基和咪唑环配位,并通过连锁反应诱导悬臂梁向镀金面偏转;而后肽链上的氮原子与Cu2+配位,同时构象发生变化,由直链转变成折叠状,进而增加链间的作用力使悬臂梁反向偏转;而Cu2+浓度低时不能实现连锁反应诱导悬臂梁表面快速的形成向内的拉力,直接通过构象变化推动悬臂梁反向偏转.考察了溶液pH值、Cl-浓度对GGH与Cu2+作用的影响,结果表明,在pH 7.0的条件下GGH与Cu2+作用导致悬臂梁偏转最大.Cl-的存在会与Cu2+形成CuCl2–xx配合物不易与肽链结合. 相似文献
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采用水热法合成2种氧化钨(WO3)纳米材料,并利用XRD和电子探针显微分析仪(EPMA)进行了表征。 利用循环伏安法研究了Pt-WO3/C电极对甲醇氧化的电催化活性。 结果表明,Pt-WO3/C催化剂对甲醇氧化的电催化活性优于Pt/C催化剂,且氧化钨质量分数为20%的Pt-氧化钨/C催化效果最好。 与青铜相氧化钨掺杂的Pt/C电极比较,掺杂焦绿石型氧化钨的Pt/C电极催化性能有很大提高,这是由于焦绿石型氧化钨表面具有较多OHads。 质量分数20%的Pt-焦绿石型氧化钨/C在0.5 mol/L CH3OH+1 mol/L H2SO4溶液中对甲醇氧化的峰电流密度达到87.2×10-3 A/cm2。 相似文献
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介稳态氧化钨超微粉体的水热合成与光致变色性质研究 总被引:5,自引:0,他引:5
Under hydrothermal conditions, the superfine powders of cubic pyrochlore-type of tungsten oxide and hexagonal tungsten bronze were obtained by using Na2WO4·2H2O as the starting material. The products were characterized by XRD, TG, IR, UV and EPMA, respectively. The effects of the pH value, the acid concentration, reaction temperature and time on the structure and particle size of products were investigated in detail. The conditions for the preparation of superfine powders of tungsten oxide were optimized. The pH 2.5~4.5 of the reaction system led to the formation of a pyrochlore phase and pH 0.5~2.0 gave the hexagonal tungsten bronze structure. The photochromism property of the hexagonal tungsten bronze was studied. The results show that pyrochlore and bronze phases are decomposed at 300 ℃ and 450 ℃, respectively. With the increasing of temperature, the structure of the two oxides changes. The pyrochlore-type powder changes completely into triclinic Na2W4O13 around 500 ℃, while the bronze phase into a mixture of Na2W6O19 and triclinic WO3 at 550 ℃. The powder of the hexagonal tungsten bronze showed better photochromism property. 相似文献
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采用沉淀结合渗析的方法,以钨酸钠、钨酸铵为原料,制备了不同形貌、具有择优取向的MxWO3·xH2O(M=Na+,NH4+,x<1)粉晶,利用SEM、XRD、TG、IR、XPS等手段对粉体进行表征,考察了不同渗析时间和焙烧温度对粉晶形貌、晶化程度及结构转变的影响。结果表明,长时间渗析后粉体的晶化程度明显提高,并沿(010)晶面方向择优生长,形貌由不规则形变为梭形和蝴蝶形。经空气气氛400 ℃焙烧后,NaxWO3·xH2O和(NH4)xWO3·xH2O粉晶均转变为沿(200)晶面方向择优生长的立方青铜相,且形貌也发生改变。 相似文献
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采用两步溶液法在陶瓷管上原位生长了ZnO纳米棒阵列,然后以ZnO纳米棒为载体,通过水热法在其表面负载α-Fe2O3纳米粒子,生成异质α-Fe2O3/ZnO复合纳米材料。 α-Fe2O3/ZnO纳米棒直径30~80 nm,长1 μm左右,交叉排列形成纳米棒阵列,α-Fe2O3纳米粒子粒径约10 nm,均匀分布在ZnO纳米棒表面。 将纯ZnO和α-Fe2O3/ZnO纳米棒阵列制成气敏元件,测试并对比了2种气敏元件的气敏性能,揭示其气敏机理。 结果表明:α-Fe2O3纳米粒子的复合显著提高了ZnO纳米棒阵列对乙醇气体的灵敏度和选择性,在工作温度370 ℃时,对100 μL/L乙醇气体的响应值为85.4,是同条件下ZnO器件对乙醇响应值(9.4)的9.1倍,响应时间7 s,最低检出限为0.01 μL/L。 相关研究可以应用于痕量乙醇的快速、高灵敏度和高选择性检测。 相似文献
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