大碳层间距的沥青基多级孔碳材料的制备及其在超级电容器中的应用

基于KOH活化法,以纳米级片层多孔MgO为模板剂,制备大碳层间距的沥青基超级电容器用多级孔碳材料。考察了模板剂添加量对多孔碳材料孔分布、碳层间距等理化性能及电化学性能的影响。结果表明模板剂添加量为沥青质量的25%时,多孔碳材料比表面积、孔体积分别为2 634 m~2·g~(-1)、1.12 cm~3·g~(-1),碳层间距高达0.374 nm,用于超级电容器电极材料时,1和20A·g~(-1)电流密度下的比电容分别为338和277 F·g~(-1),经过10 000次循环恒电流充放电,1 A·g~(-1)下容量保持率为93.5%,展现了优异的电化学性能。     

α-磷酸锆插层复合材料制备及其对Cs~+吸附性能的研究

文中采用预撑插层的方法成功的将大环化合物二苯并-21-冠-7引入α-磷酸锆(α-ZrP)材料进行预插层,获得新型二苯并-21-冠-7插层α-ZrP复合材料。由于二苯并-21-冠-7插入显著提高了α-ZrP材料对Cs~+的吸附容量,其最大可达298.2 mg·g~(-1),远优于未插层的α-ZrP材料(64.1 mg·g~(-1))。本实验的开展为新型吸附材料设计与制备提供了新的思路和线索。     

甲基橙/水滑石复合颜料制备与表征

采取共沉淀法制备不同阴离子插层的锌铬水滑石(ZnCr-LDHs),通过ZnCr-LDHs吸附甲基橙(MO)制备有机-无机复合颜料。采用XRD、FT-IR和TG-DTA对不同阴离子插层的ZnCr-LDHs结构和热稳定性能进行表征,研究了吸附剂种类、吸附温度、MO初始浓度和溶液pH值等因素对复合颜料中MO吸附量的影响。研究结果表明:ZnCr-LDHs结构参数的差异与插层阴离子的种类、电荷和空间结构有关,并影响其对MO的吸附量。ZnCr-CO_3-LDHs的层间距最小,但对MO的吸附容量最大,ZnCr-CO_3-LDHs吸附MO至层板上形成复合颜料。当反应温度313 K,MO初始浓度为100 mg·L~(-1),吸附时间为2 h时,制备得到的复合颜料中MO吸附容量为88.56 mg·g~(-1)。酸性条件下ZnCr-CO_3-LDHs对MO的吸附容量明显高于碱性条件下,溶液初始pH值为3时,吸附容量达到最大值为190.93 mg·g~(-1)。     

Na~+插层与MWCNTs隔离对石墨烯结构调控及电容性能

利用水热法制备的还原氧化石墨烯(RGO)由于重新堆叠和团聚严重影响了其超级电容器性能.本文工作中,水热反应前在氧化石墨烯(GO)溶液中依次加入NaCl和多壁碳纳米管(MWCNTs),基于Na~+插层和MWCNTs隔离作用,可有效阻碍RGO片层的重新聚集,得到均一、分散的多级孔结构.对于RGO-Na-MWCNTs,其比表面积可达571.2 m~2·g~(-1),介孔和大孔比例也都得到了明显增加,这为电荷聚集和离子扩散提供了更多活性区域和扩散通道.纯离子液体系中(室温环境下),该优化的聚集结构使得RGO-Na-MWCNTs获得了较高的比容量245.6 F·g~(-1)(2 mV·s~(-1))以及优越的电化学性能.这种利用Na+插层和MWCNTs隔离的协同效应为制备可分散二维层状材料提供了实验基础,并促进了石墨烯基超级电容器的商业化应用.     

氧化石墨阳离子交换容量测定过程中结构的变化

氧化石墨(GO)结构层上的碳羟基(―C―OH)和边缘羧基(―COOH)在水介质中发生质子化反应解离出的H+具有阳离子可交换性。实验采用甲醛缩合法测量了GO的阳离子交换容量(CEC),用X射线衍射(XRD)、傅里叶变换红外(FTIR)光谱和X射线光电子能谱(XPS)分析测试手段对GO阳离子交换过程中间产物的结构变化进行了分析。结果表明,GO的CEC高达541.48 mmol/100 g。NH_4~+和Ca~(2+)交换后的GO,保持稳定的层状结构,c轴方向层间距分别增大了0.1499和0.2905 nm。NH_4+和Ca~(2+)主要以层间可交换阳离子形式存在于层间域中,并与水分子形成可交换水化阳离子层,部分以[NH_4(H_2O)_6]+和[Ca(H_2O)_6]_2+的形式存在于结构层的边缘附近,共同平衡结构层水解产生的负电荷。     

顺式二胺基二苯并-18-冠-6插层α-磷酸锆复合材料的制备及对锶吸附性能的研究

使用直接插层法制备了顺式二胺基二苯并18-冠-6(cis-DAmDB18C6)插层α-磷酸锆(α-ZrP)材料,通过静态吸附实验,对比了顺式二胺基二苯并18-冠-6插层磷酸锆材料和α-磷酸锆对Sr~(2+)的吸附性能。实验结果表明,二胺基二苯并-18-冠-6插层磷酸锆材料对Sr~(2+)的吸附平衡时间约48h,中性溶液高温有利于吸附,低温高酸有利于解吸,最大吸附容量为125mg·g~(-1),这种插层材料对Sr~(2+)的吸附能力优于α-磷酸锆。     

碳酸盐共沉淀法可控制备超高倍率锂离子电池正极材料LiNi_(1/3)Co_(1/3)Mn_(1/3)O_2

采用碳酸盐共沉淀法通过调节NH_3·H_2O用量来实现可控制备超高倍率纳米结构LiNi_(1/3)Co_(1/3)Mn_(1/3)O_2正极材料。NH_3·H_2O用量会对颗粒的形貌、粒径、晶体结构以及材料电化学性能产生较大的影响。X射线衍射(XRD)分析和扫描电镜(SEM)结果表明,随着NH_3·H_2O用量的降低,一次颗粒形貌由纳米片状逐渐过渡到纳米球状,且nNH_3·H_2O∶(nNi+nCo+nMn)=1∶2样品晶体层状结构最完善、Li~+/Ni~(2+)阳离子混排程度最低。电化学性能测试结果也证实了nNH_3·H_2O∶(nNi+nCo+nMn)=1∶2样品具有最优异的循环稳定性和超高倍率性能。具体而言,在2.7~4.3 V,1C下循环300次后的放电比容量为119 m Ah·g~(-1),容量保持率为81%,中值电压基本无衰减(保持率为97%)。在100C(18 Ah·g~(-1))的超高倍率下,放电比容量还能达到56 m Ah·g~(-1),具有应用于高功率型锂离子电池的前景。此NH_3·H_2O比例值对于共沉淀法制备其他高倍率、高容量的正/负极氧化物材料具有一定的工艺参考价值。     

离子色谱法测定水利工程水样中的5种无机阳离子

提出新型高通量离子色谱仪快速测定水利工程水样中5种阳离子Na~+、NH_4~+、Mg~(2+)、Ca~(2+)和K~+的含量的方法。采用TSKgel Super IC-CR阳离子交换柱,以2.2 mmol·L~(-1)甲基磺酸和1.00 mmol·L~(-1)18冠醚6的混合液为淋洗液,流量为0.7 mL·min~(-1),柱温为40℃,凝胶抑制电导检测,可在18 min内完成对5种阳离子的分析。5种无机阳离子的质量浓度在一定范围内与其峰面积呈线性关系,Na~+、NH_4~+、Mg~(2+)、Ca~(2+)和K~+的检出限(3S/N)分别为7.1,6.3,9.5,10.0,8.3μg·L~(-1),水样的加标回收率为95.3%~104%,相对标准偏差(n=5)为0.26%~4.0%。     

层状(脯氨酸-N-甲基膦酸-磷酸氢)锆的合成及插层性能研究

以高结晶度制备了层状(脯氨酸-N-甲基膦酸-磷酸氢)锆(α-ZPMPP)晶体(层间距为1.52nm),并研究了其常温下对正丁胺的插层性能,用元素分析、IR、XRD和TG-DSC热分析对α-ZPMPP及其插层复合物进行了表征.结果表明,层状α-ZPMPP具有形成超分子主-客体化合物的插层性能,正丁胺客体分子在主体底物中形成单分子层,并插入α-ZPMPP中,使层间距增大0.45nm,插入的正丁胺可在150～250℃被脱除.     

简便的两步直接固相反应法制备N、Se共掺杂碳限域的NiSe纳米晶及其储钠性能

通过简便的两步直接固相反应,即在室温下的固相自组装反应制备Ni席夫碱配合物前驱体,然后通过高温固相热解碳化和硒化反应,原位制备了N,Se共掺杂碳限域的NiSe纳米晶复合物。采用X射线衍射(XRD)、扫描电镜(SEM)、透射电镜(TEM)、X射线光电子能谱(XPS)和热重分析(TGA)等表征技术分别对其物相、形貌结构、组分和含量等进行分析,并通过循环伏安、恒电流充放电和电化学阻抗谱等方法测试其电化学储钠性能。研究结果表明,复合物中NiSe粒子的平均尺寸为100 nm,被均匀限域在N,Se共掺杂的碳基体中;得益于该结构的优势,复合物作为钠离子电池负极材料时,在0.1 A·g~(-1)的电流密度下充放电循环100次后仍保持291 mAh·g~(-1)的可逆充电比容量,保持了首圈充电比容量的88%。同时,在5 A·g~(-1)的电流密度下,可逆充电比容量为197 mAh·g~(-1)。     

Interlayer-expanded MoS<Subscript>2</Subscript>/graphene composites as anode materials for high-performance lithium-ion batteries

A facile strategy was developed to prepare interlayer-expanded MoS₂/graphene composites through a one-step hydrothermal reaction method. MoS₂ nanosheets with several-layer thickness were observed to uniformly grow on the surface of graphene sheets. And the interlayer spacing of MoS₂ in the composites was determined to expand to 0.95 nm by ammonium ions intercalation. The MoS₂/graphene composites show excellent lithium storage performance as anode materials for Li-ion batteries. Through gathering advantages including expanded interlayers, several-layer thickness, and composited graphene, the composites exhibit reversible capacity of 1030.6 mAh g^?1 at the current density of 100 mA g^?1 and still retain a high specific capacity of 725.7 mAh g^?1 at a higher current density of 1000 mA g^?1 after 50 cycles.     

MoS2 Nanoflowers with Expanded Interlayers as High‐Performance Anodes for Sodium‐Ion Batteries

MoS₂ nanoflowers with expanded interlayer spacing of the (002) plane were synthesized and used as high‐performance anode in Na‐ion batteries. By controlling the cut‐off voltage to the range of 0.4–3 V, an intercalation mechanism rather than a conversion reaction is taking place. The MoS₂ nanoflower electrode shows high discharge capacities of 350 mAh g^?1 at 0.05 A g^?1, 300 mAh g^?1 at 1 A g^?1, and 195 mAh g^?1 at 10 A g^?1. An initial capacity increase with cycling is caused by peeling off MoS₂ layers, which produces more active sites for Na⁺ storage. The stripping of MoS₂ layers occurring in charge/discharge cycling contributes to the enhanced kinetics and low energy barrier for the intercalation of Na⁺ ions. The electrochemical reaction is mainly controlled by the capacitive process, which facilitates the high‐rate capability. Therefore, MoS₂ nanoflowers with expanded interlayers hold promise for rechargeable Na‐ion batteries.     

Coordination‐Driven Hierarchical Assembly of Silver Nanoparticles on MoS2 Nanosheets for Improved Lithium Storage

We report a novel strategy for the hierarchical assembly of Ag nanoparticles (NPs) on MoS₂ nanosheets through coordination by using a multifunctional organic ligand. The presence of Ag NPs on the surface of MoS₂ nanosheets inhibits their agglomeration, thereby providing increased interlayer spacing for easy Li⁺ ion intercalation. Such a unique hybrid architecture also ensures sufficient percolation pathways on the whole surface of the MoS₂ nanosheets. Moreover, the high rigidity and low deformability of the Ag NPs effectively preserve the hybrid architecture during the charge–discharge process, which translates into a high cycle stability. A prominent synergistic effect between MoS₂ and Ag is witnessed. When the Ag content is only 5 wt %, the Ag–MoS₂ hybrid delivers a reversible capacity as high as 920 mA h g^?1 at a current density of 100 mA g^?1, making the Ag–MoS₂ hybrid an attractive candidate for next‐generation LIBs.     

Preparation and Characterization of TiO2-pillared Layered HNb3O8

IntroductionThelayeredcompoundssuchassmectiteclays,me-tallicphosphatesandtransitionmetaloxidespillaredwithinorganicoxideshavebeenattractingmoreandmoreattentionfrombothacademicandindustrialfieldsduetotheirpotentialapplicationsinadsorption,separa-tion,conductionandparticularlycatalysis.1-7NiobatessuchasKNb3O8andK4Nb6O17,andthecorrespondingprotonicoxides,HNb3O8andH4Nb6O17,aremembersofthefamilyoflayeredtransitionmetaloxidesbasedonoctahedralframeworkstructure,inwhichK+orH+liesbetweenlayersbuil…     

Phase engineering of cobalt hydroxide toward cation intercalation

Multi-cation intercalation in aqueous and neutral media is promising for the development of high-safety energy storage devices. However, developing a new host matrix for reversible cation intercalation as well as understanding the relationship between cation intercalation and the interlayer structure is still a challenge. In this work, we demonstrate layered cobalt hydroxides as a promising host for cation interaction, which exhibit high metal ion (Li⁺, Na⁺, K⁺, Mg²⁺ and Ca²⁺) storage capacities after phase transformation. Moreover, it is found that α-Co(OH)₂ with an intercalated structure is more conducive to phase transition after electrochemical activation than β-Co(OH)₂. As a result, the activated α-Co(OH)₂ delivers four times higher capacity in multi-cation storage than activated β-Co(OH)₂. Meanwhile, the α-Co(OH)₂ after activation also shows an ultralong cycle life with capacity retention of 93.9% after 5000 cycles, which is also much superior to that of β-Co(OH)₂ (∼74.8%). Thus, this work displays the relationship between cation intercalation and the interlayer structure of layered materials, which is important for designing multi-ion storage materials in aqueous media.

Phase engineering of cobalt hydroxide toward cations intercalation is explored. Among them, α-Co(OH)₂ is proven to be more conductive to phase transition than β-Co(OH)₂ during electrochemical activation, which shows superior multi-cations storage performance.     

CdS插层的K4Nb6-xCuxO17复合物的制备及其光催化制氢活性

以Nb2O5,K2CO3和CuO为原料经高温固相反应合成K4Nb6-xCuxO17催化剂,并通过层间离子交换反应,胺插入反应以及硫化反应制备CdS插层K4Nb6-xCuxO17复合催化剂(K4Nb6-xCuxO17/CdS)。利用X射线衍射(XRD),X射线光电子能谱(XPS),场发射扫描电镜(SEM),X射线能谱仪(EDX),紫外-可见漫反射(UV-Vis),分子荧光光谱(PL)等技术对催化剂进行表征。考察了催化剂的可见光催化制氢活性。结果表明,Cu离子掺杂进入K4Nb6O17晶格中,CdS位于K4Nb6O17层间。CdS插层K4Nb6-xCuxO17催化剂的最大吸收光波长约为550 nm。催化剂制氢活性有明显提高,紫外光和可见光下3 h产氢量分别达到279.83 mmol.gcat-1和7.11 mmol.gcat-1。最后讨论了复合催化剂光生电荷转移机理。     

水系混合离子全电池LiMn2O4//NaTi2(PO4)3

分别以LiMn_2O_4,NaTi_2(PO_4)_3为正负极,1 mol·L~(-1) Li_2SO_4和0.5 mol·L~(-1) Na_2SO_4的混合水溶液为电解液组装成一种水系混合离子全电池。分别将正负极材料在3种不同水相电解液(1 mol·L~(-1) Li_2SO_4、0.5 mol·L~(-1)Na_2SO_4以及1 mol·L~(-1) Li_2SO_4+0.5 mol·L~(-1)Na_2SO_4混合电解液)中进行循环伏安和恒流充放电测试,结果发现,LiMn_2O_4在上述电解液中仅有Li~+的脱出/嵌入而Na~+由于半径较大而不参与该过程,NaTi_2(PO_4)_3在3种电解液中Li+、Na+均参与嵌入/脱嵌过程,且Li~+和Na~+的嵌入/脱出峰电位相差不大,分别为-0.82和-0.64 V,-0.95和-0.75 V;全电池在265 mA·g~(-1)电流密度下平均放电电压为1.55 V,充放电比容量分别为100.1和74.9 m Ah·g~(-1)。     

两个含双磺酸基团化合物的合成、晶体结构及荧光性质

采用缓慢蒸发溶剂法在水中合成了2个含双磺酸基的化合物A-2,5-DSA·（Hphen）₂·2H₂O（1）和[Co（phen）₂（H₂O）₂]·（A-2,5-DSA）·3H₂O（2）（A-2,5-DSA=苯胺-2,5-二磺酸根离子,phen=1,10-邻菲罗啉）。化合物1中,相邻的质子化的1,10-邻菲罗啉反向堆叠在一起,水分子通过氢键与（Hphen）+和苯胺-2,5-二磺酸根离子相连,形成二维的层状结构。配合物2中,钴离子与2个1,10-邻菲罗啉和2个水分子配位,构成[Co（phen）₂（H₂O）₂]²⁺阳离子。3个自由的水分子通过氢键将苯胺-2,5-二磺酸根离子和[Co（phen）₂（H₂O）₂]²⁺连接形成三维网状结构。两个化合物中苯胺-2,5-二磺酸根离子均起到平衡电荷的作用。室温下2个化合物均具有荧光性质,其最大发射峰分别在601nm和441nm。     

The intercalation of transition metal salen complexes into layered MoS2

Exfoliation-restack method has been employed to synthesize the intercalation compounds based on the cationic complexes [M(Salen)]⁺ (M = Mn³⁺, Fe³⁺, Co³⁺; Salen = N, N′-ethylene-bis(salicylaldimine)) into the layered MoS₂. Their conductivity is in the range of 0.04–0.1 S/cm, which is much higher than the pristine MoS₂. Magnetic measurement indicated that the intercalation compounds [Mn(Salen)]_0.18MoS₂ · 0.25H₂O and [Fe(Salen)]_0.12MoS₂ · 0.3H₂O exhibit the temperature-dependent paramagnetism, which obviates from the Curie–Weiss law due to the temperature-independent paramagnetism of the exfoliated MoS₂ slabs, while [Co(Salen)]_0.14MoS₂ · 0.5H₂O exhibits the almost temperature-independent paramagnetism. All three intercalation compounds do not show magnetic spin crossover behavior.     

两个含双磺酸基团化合物的合成、晶体结构及荧光性质(英文)

采用缓慢蒸发溶剂法在水中合成了2个含双磺酸基的化合物A-2,5-DSA·(Hphen)2·2H2O(1)和[Co(phen)2(H2O)2]·(A-2,5-DSA)·3H2O(2)(A-2,5-DSA=苯胺-2,5-二磺酸根离子,phen=1,10-邻菲罗啉)。化合物1中,相邻的质子化的1,10-邻菲罗啉反向堆叠在一起,水分子通过氢键与(Hphen)+和苯胺-2,5-二磺酸根离子相连,形成二维的层状结构。化合物2中,钴离子与2个1,10-邻菲罗啉和2个水分子配位,构成[Co(phen)2(H2O)2]2+阳离子。3个自由的水分子通过氢键将苯胺-2,5-二磺酸根离子和[Co(phen)2(H2O)2]2+连接形成三维网状结构。两个化合物中苯胺-2,5-二磺酸根离子均起到平衡电荷的作用。室温下2个化合物均具有荧光性质,其最大发射峰分别在601 nm和441 nm。