Surface status and size influences of nickel nanoparticles on sulfur compound adsorption

Metallic nickel nanoparticles were incorporated on mesoporous silica to remove sulfur compounds in diesel selectively. In the first method, nickel nanoparticles were formed on mesoporous silica SBA-15 by impregnation and subsequent reduction of nickel nitrate. The sulfur adsorption capacity was strongly dependent on the nickel loading and the average nickel particle size. In the second method, nickel nanoparticles were synthesized in solution in the presence of a capping agent and then incorporated in mesoporous silica MCF by sonication. Although these particles maintain their sizes on the MCF surface after heat treatment, capping agent remaining on the Ni particle surface might interfere the adsorption of sulfur compounds.     

One-step hydrothermal synthesis of feather duster-like NiS@MoS<Subscript>2</Subscript> with hierarchical array structure for the Pt-free dye-sensitized solar cell

Novel feather duster-like nickel sulfide (NiS) @ molybdenum sulfide (MoS₂) with hierarchical array structure is synthesized via a simple one-step hydrothermal method, in which a major structure of rod-like NiS in the center and a secondary structure of MoS₂ nanosheets with a thickness of about 15–55 nm on the surface. The feather duster-like NiS@MoS₂ is employed as the counter electrode (CE) material for the dye-sensitized solar cell (DSSC), which exhibits superior electrocatalytic activity due to its feather duster-like hierarchical array structure can not only support the fast electron transfer and electrolyte diffusion channels, but also can provide high specific surface area (238.19 m² g^?1) with abundant active catalytic sites and large electron injection efficiency from CE to electrolyte. The DSSC based on the NiS@MoS₂ CE achieves a competitive photoelectric conversion efficiency of 8.58%, which is higher than that of the NiS (7.13%), MoS₂ (7.33%), and Pt (8.16%) CEs under the same conditions.

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Graphical abstract Novel feather duster-like NiS@MoS₂ hierarchical structure array with superior electrocatalytic activity was fabricated by a simple one-step hydrothermal method.

     

A Modified Technique for the Preparation of SO2 from Sulphates and Sulphides for Sulphur Isotope Analyses

Abstract

A modified technique for the conversion of sulphates and sulphides to SO₂ with the mixture of V₂O₅—SiO₂ for sulphur isotopic analyses is described. This technique is more suitable for routine analysis of large number of samples. Modification of the reaction vessel and using manifold inlet system allows to analyse up to 24 samples every day. The modified technique assures the complete yield of SO₂, consistent oxygen isotope composition of the SO₂ gas and reproducibility of δ³⁴S measurements being within 0.10‰. It is observed, however, oxygen in SO₂ produced from sulphides differs in δ¹⁸O with respect to that produced from sulphates.     

固定漆酶聚苯胺-CoC2O4纳米复合物修饰电极的直接电化学

采用循环伏安法、微分脉冲伏安法、交流阻抗谱以及计时电流法等电化学方法,结合红外光谱、紫外-可见分光光度法、原子力显微镜、透射电子显微镜以及原子吸收光谱等辅助手段,表征了固定漆酶的聚苯胺-草酸钴纳米复合物的化学组成、结构和形貌,测试了纳米复合物固酶前后的导电性能的变化,研究了纳米复合物修饰电极上固定漆酶的直接电化学行为,评估了该电极的催化氧还原效能以及作为电化学传感器检测氧分子的性能。实验结果表明该电极在不含电子介体的溶液中以酶活性中心T2作为首要电子受体,将得到电子传递给化学吸附的氧气使其被电还原,其表观电子迁移速率为0.017 s~(-1),且具有良好的催化氧还原性能(氧还原起始电位:460 m V vs NHE,转化氧分子为水的表观速率常数为2.6×10-4 s~(-1)),酶电催化氧还原为水分子步骤为反应的速控步。该电极作为电化学传感器对氧具有极低检测限(0.20μmol·L~(-1)),宽线性响应范围(0.4~7.5μmol·L~(-1))以及对底物高亲和力(KM=122.4μmol·L~(-1))等优势。     

链酚胺型配体锌(Ⅱ)配合物模拟碳酸酐酶研究

合成了酚胺型链状配体,N,N'-二(2-羟基苄基)丙二胺(H~2L)及其Zn(Ⅱ)配合物(ZnL),通过元素分析、IR和^1HNRM等手段进行了表征。采用pH电位滴定法,在25℃±0.1℃,I=0.1mol·dm^-^3(KNO~3)条件下,测定了配体的质子化常数以及配体与金属离子Zn(Ⅱ)配位反应平衡常数。讨论了配体与金属离子Zn(Ⅱ)的配位情况,得到了配位酚羟基的解离常数。运用分光光度法,在25℃±0.1℃,I=0.1mol·dm^-^3(KNO~3)条件下,在pH=5.5～9.0(50mmol·dm^-^3缓冲溶液)范围内,研究了配合物作为碳酸酐酶模拟物催化对-硝基苯酚乙酸酯(NA)水解动力学,得到了NA酯水解的配合物催化速率常数k~N~P。实验结果表明,ZnHL^+的配位酚羟基的解离常数pK~a为6.83;催化速率常数k~N~P与pH之间不存在Sigmoidal型曲线关系,而是在pH值中性附近有最大值,ZnHL^+对NA酯水解有很好的催化效果,并且采取双重催化机理,是碳酸酐酶很好的模拟物。     

含羧酸配体的鼓形有机锡氧簇合物：六聚苯基锡氧3-吲哚丁酸酯的合成及晶体结构

利用Ph3SnOH和3-吲哚丁酸以1：1摩尔比反应，合成了新型含羧酸配体的鼓形 有机锡氧簇合物：六聚苯基锡氧3-吲哚西酸酯。通过元素分析、红外光谱和X射线 单晶衍射对其结构进行了表征。测试结果表明：该化合物为三斜晶系，空间群P1， a=1.1722(6),b=1.5694（8）nm，c=1.7227(9)nm，α=116.251（8）°，β=100. 854（10）°，γ=95.606（9）°，Z=1，V=2.732(3)nm^3，Dc=1.554g·cm^-3，μ =1.420mm^-1，F(000)=1276，R=0.0630，ωR=0.0762。晶体结构中，六配位的锡原 子呈畸变的八面体构型。     

用时间分辨光谱研究红细胞悬液的荧光发射

实验获得了激光照射红细胞悬液的荧光光谱,并分别监测不同荧光峰值波长处强度随时间的衰变过程,测试了其相应的荧光寿命.结果表明,在波长为407 nm的激光照射下,红细胞悬液向外发射中心波长分别位于596,628,692 nm的荧光光谱,各荧光峰对应衰变过程的平均荧光寿命分别为1.97,13.31,14.58 ns.利用荧光强度和吸收率的加和性表示了混合物的总吸收率和总荧光发射强度,通过理论计算获得了红细胞悬液中锌卟啉、原卟啉和其他游离物参与荧光发射的相对含量和相对强度在不同荧光峰位的变化关系,进一步解释了不同峰位处荧光发射强度和平均荧光寿命的变化原因.     

薄膜梯度扩散-分光光度法富集测量水中痕量Mo (VI)

建立了薄膜梯度扩散(DGT)- 硫氰酸钾(PT)分光光度法(DGT-PT法)富集测量水中痕量Mo (VI) 的分析方法。本研究先以聚季铵盐(PQAS)溶液为结合相的DGT技术 (PQAS DGT) 原位分离富集水中Mo (VI),再以PT分光光度法测定DGT结合相中Mo (VI)的含量,最后依据DGT方程计算水中Mo (VI)的浓度。DGT-PT法测得配制水中Mo ( VI) 的回收率为96.3% ~ 101.3%,相对标准偏差(RSD)为1.3% ~4.0%;测得工业废水中Mo (VI) 的浓度为27.13 ~ 121.79mg/L,加标回收率为96.0% ~ 101.6%。当采样时间为48h,PQAS DGT对水中Mo (VI) 富集近18倍,可显著降低分析方法的检测限,实现水中痕量Mo (VI) 的定量检测。     

聚苯胺盐在无溶剂条件下有效催化羰基保护反应

合成了自掺杂聚苯胺盐PABSA,并成功应用于醛和乙酸酐的缩醛化反应,发现此聚苯胺盐催化剂具有高效、可回收等特性。同时,利用二元醇作为保护基团,醛也可以转化成相应的缩醛。考察了反应时间、温度和催化剂用量对反应的影响,并通过IR、1H NMR、13C NMR和元素分析对部分产物进行了结构表征。