Strategy of Graphdiyne (g−CnH2n-2 ) Preparation Coupling with the Flower-Like NiAl-LDH Heterojunctions for Efficient Photocatalytic Hydrogen Evolution**

Graphdiyne (g−C_nH_2n-2), a novel two-dimension carbon allotrope material composed of a sp- and sp²-hybrid carbon network, has been widely explored since it was synthesized for the first time by Li's group in 2010. A series distinct and excellent properties bestow graphdiyne excellent performance in many fields. Here, an innovative progress for preparing graphdiyne by using Cu⁺ contained material as catalyst is reported and the composite CuI-GD is coupled with flower-like NiAl-LDH to produce H₂ from photocatalytic water splitting. The results of FTIR and Raman spectroscopy together reveal that graphdiyne nanosheets are synthesized successfully by employing a cross-coupling method. Photocatalytic hydrogen evolution performance shows that the hydrogen production activity of CuI-GD/NiAl-LDH has a 15- and 216-fold enhancement compared with CuI-GD and NiAl-LDH, respectively. A series of characterizations are carried out to expound the underlying reasons in the enhancement of the photocatalytic hydrogen production performance of CuI-GD/NiAl-LDH. Meanwhile, a possible mechanism for the photocatalytic hydrogen evolution process was proposed to understand the interaction among these materials.     

A Lamellar Coordination Polymer with Remarkable Catalytic Activity

A positively charged lamellar coordination polymer based on a flexible triphosphonic acid linker is reported. [Gd(H₄nmp)(H₂O)₂]Cl ? 2 H₂O ( 1 ) [H₆nmp=nitrilotris(methylenephosphonic acid)] was obtained by a one‐pot approach by using water as a green solvent and by forcing the inclusion of additional acid sites by employing HCl in the synthesis. Compound 1 acts as a versatile heterogeneous acid catalyst with outstanding activity in organic reactions such as alcoholysis of styrene oxide, acetalization of benzaldehyde and cyclohexanaldehyde and ketalization of cyclohexanone. For all reaction systems, very high conversions were reached (92–97 %) in only 15–30 min under mild conditions (35 °C, atmospheric pressure). The coordination polymer exhibits a protonic conductivity of 1.23×10^?5 S cm^?1 at 98 % relative humidity and 40 °C.     

交换时间对离子交换法合成谷氨酸/锌铝层状双氢氧化物的结构和热稳定性的影响

采用离子交换法实现了谷氨酸(Glu)插层到ZnAl层状双氢氧化物(ZnAl-LDH)中而形成Glu/ZnAl-LDH纳米复合材料,并用X射线衍射(XRD)、傅里叶变换红外(FT-IR)光谱、透射电子显微镜(TEM)以及热失重-差热(TG-DTA)分析等测试技术,研究了交换时间对Glu/ZnAl-LDH纳米复合材料结构的影响。发现当交换时间为1d时,Glu/ZnAl-LDH纳米复合材料粒子的结晶度好,Glu分子均以垂直形式插入,此时Glu在层间达到交换平衡。当交换时间为2d时,部分Glu开始以水平方式插入ZnAl-LDH纳米材料层间。但当交换时间进一步延长时,ZnAl-LDH纳米材料的结构发生部分坍塌,而且ZnAl-LDH纳米材料在微酸性的Glu溶液中发生部分溶解而使其六边形的结构出现破损。由于Glu插入ZnAl-LDH纳米复合材料层间后,其稳定性得到提高,因此,ZnAl-LDH纳米材料可以作为优良的生物分子的载体和储存器。     

含Fe、Co、Ni的层状双金属氢氧化物为催化剂前体生长碳纳米管

分别以具有相似Fe、Co、Ni含量的层状双金属氢氧化物(LDHs)为催化剂前体,用化学气相沉积的方法生长碳纳米管(CNTs).催化剂由LDHs焙烧还原得到.通过X射线衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)及拉曼光谱(Raman)测试技术对LDHs及其焙烧产物的结构、CNTs的形貌和结构进行了研究.结果表明,3种催化剂生长的CNTs均为多壁结构;其中Co催化剂活性较低,生长CNTs的管径较细、石墨化程度较高;Ni催化剂的活性较高,生长CNTs的密度较大、管壁较厚、石墨化程度较差;Fe催化剂的活性介于Co和Ni之间.催化剂活性及CNTs的密度可以由生长CNTs的结构来解释.     

含Fe(Ⅲ)离子有机-无机层状类钙钛矿杂合物修饰电极对对苯二酚的电催化作用及测定

以酚藏花红为有机层、含三价铁的K3Fe(CN)6为无机层在空气中合成了有机-无机层状类钙钛矿杂合物修饰碳糊电极。利用扫描电镜(SEM)和X-射线衍射(XRD)对其表面形貌和微观结构进行表征,并用循环伏安法研究了杂合物修饰电极的电化学性质,发现该电极对对苯二酚具有良好的电催化作用。结果表明,在pH5.0的PBS缓冲溶液中,对苯二酚在空白碳糊电极上为二步还原过程而在修饰电极上只有一步还原过程,修饰电极更有利于检测对苯二酚。采用微分脉冲伏安法在-0.4～0V电位范围内进行扫描,在-240.2mV处的还原峰电流与对苯二酚浓度在1.0×10-6～1.0×10-3mol/L范围呈良好的线性关系,相关系数为0.9951,检出限为4.73×10-7mol/L。对1.0×10-5mol/L的对苯二酚连续测定5次,相对标准偏差为1.8%。模拟样品中对苯二酚的平均加标回收率为102%。     

以[M(DETA)2)]n+(M=Cu2+, Ni2+, Co3+)为客体的MnPS3夹层化合物的合成、结构表征与磁性研究

将过渡金属配合物阳离子([M(DETA)₂]ⁿ⁺(M=Cu²⁺,Ni²⁺,Co³⁺;DETA=Diethylenetriamine,二乙烯三胺)作为客体插入层状MnPS₃层间得到了相应的3个夹层化合物。通过X-射线粉末衍射、元素分析和红外光谱对夹层化合物的结构进行了表征。结果表明,与主体MnPS₃ 0.65 nm的层间距相比较,夹层化合物(Mn_0.88PS₃[Cu(DETA)₂]_0.12)的层间距扩大了0.32 nm,由此推测客体[Cu(DETA)₂]²⁺在层间以平面四方的配位形式存在,而另2个夹层化合物(Mn_0.79PS₃[Ni(DETA)₂]_0.21和Mn_0.74PS₃[Co(DETA)₂]_0.17)的层间距扩大了0.48 nm,说明客体[(M(DETA)₂]ⁿ⁺,M=Co³⁺,Ni²⁺) 在主体层间以八面体配位形式存在。磁性测试结果表明过渡金属离子[(M(DETA)₂]ⁿ⁺(M=Cu²⁺,Co³⁺)的插入能引起主体MnPS₃的磁性在35~40 K发生由顺磁向亚铁磁性的转变并表现自发磁化,而客体[Ni(DETA)₂]²⁺却使夹层化合物的反铁磁相互作用增强,抑制了自发磁化的发生。     

两个二维层状4-双(咪唑基-1-甲基)-苯钴和镍配位聚合物的合成与表征

以1,4-双(咪唑基-1-甲基)-苯(bix)为配体,间苯二甲酸(IPA)为辅助配体,合成制备了两种新型同构配位聚合物:{[Ni(bix)(IPA)(H_2O)]}_n(1)和{[Co(bix)(IPA)(H_2O)]}_n(2)。单晶结构表明,此两个配合物均形成二维层状空间结构,金属原子均为六配位八面体结构,赤道平面上四个配位原子来自间苯二甲酸和配位水分子,轴向两个配位原子为bix配体的咪唑环上的N原子。金属原子通过配体连接形成四连接的二维4(4).6(2)方格层状结构。     

磷酸二氢根插层水滑石的制备及其选择性红外吸收性能

采用成核/晶化隔离法制备了镁铝碳酸根型水滑石(MgAl-CO3-LDHs),以其为前驱体,在酸性条件下通过离子交换将磷酸二氢根阴离子组装到水滑石层间,制备了具有超分子插层结构的MgAl-H2PO4-LDHs,并采用XRD、FTIR、TG-DTA-DTG、SEM和ICP等手段进行了表征。采用母粒工艺将MgAl-CO3-LDHs和MgAl-H2PO4-LDHs添加到聚乙烯(PE)中制备了LDHs/PE薄膜,研究其红外吸收性质发现,添加MgAl-H2PO4-LDHs的PE薄膜在7～25μm特别是9～11μm范围的红外吸收率明显高于添加MgAl-CO3-LDHs的薄膜,表现出显著的选择性红外吸收性能。