无定形介孔磷酸锆固定葡萄糖氧化酶的直接电化学

利用无定形介孔磷酸锆(ZrP)为载体,通过吸附法固定葡萄糖氧化酶(GOD),修饰玻碳(GC)电极得到GOD/ZrP/GC电极。在0.1 mol·L^-1磷酸盐缓冲溶液中,利用循环伏安法研究了GOD/ZrP/GC电极的直接电化学行为和对葡萄糖的催化性能。结果表明,无定形磷酸锆ZrP为载体修饰的电极GOD/ZrP/GC其电化学反应电子转移速率快、表观覆盖量大;对葡萄糖的检测表现出较快的电流响应和较高的灵敏度,说明无定形磷酸锆更有利于GOD的固定和酶电极的直接电化学。     

壳聚糖/纤维素复合微球对Cu2+的吸附

制备壳聚糖/纤维素(CS/CE)和交联壳聚糖/纤维素(ECS/CE)复合微球,用于吸附重金属离子,考察了微球对Cu2+的吸附性能。溶解性测试表明交联反应可提高微球在酸性介质中的化学稳定性。静态吸附表明,CS/CE和ECS/CE均能有效吸附Cu2+,pH 6附近吸附容量最大。吸附等温线与Langmuir和Freundlich模型均吻合,由Lang-muir模型得到的Cu2+饱和吸附容量分别为38.76 mg/g(CS/CE)和34.13 mg/g(ECS/CE)。CS/CE和ECS/CE对Cu2+的吸附初期为内扩散控制,但后期为配合反应控制。FTIR和X-射线光电子能谱(XPS)分析表明,壳聚糖中的N为Cu2+的主要吸附位,发生表面配合吸附。     

Ru(bpy)2(NCS)2染料敏化PbS/Zn2+--TiO2复合半导体纳米多孔膜电极的光电化学

采用水热法合成了Zn2+离子掺杂的TiO2纳米粒子(掺杂量0.5%),并用光电化学方法研究了Ru(bpy)2(NCS)2(bpy=2,2'-bipydine-4,4'-dicarboxylicacid)分别敏化Zn2+掺杂的TiO2电极和PbS/Zn2+-TiO2复合半导体纳米多孔膜电极的光电化学行为.实验证明Ru(bpy)2(NCS)2敏化PbS/Zn2+-TiO2复合半导体纳米多孔膜电极比单独敏化Zn2+-TiO2电极的光电效果好,且敏化电极的光电流产生的起始波长都比Zn2+-TiO2电极向长波方向移动;在360600nm范围内,Ru(bpy)2(NCS)2敏化PbS/Zn2+-TiO2复合半导体纳米多孔膜电极比单独敏化Zn2+掺杂TiO2电极的效果更好.     

导电聚邻苯二胺的合成及在染料敏化太阳能电池中的应用

制备了聚邻苯二胺,并将其作固体传输材料应用在染料敏化太阳能电池中。用光电化学方法研究了染料酸性湖蓝、聚邻苯二胺(PoPD)、二氧化钛(TiO2)纳米晶电极以及用酸性湖蓝和PoPD复合敏化TiO2纳米晶膜电极的光电化学行为。用聚邻苯二胺作为固体电解质,染料酸性湖蓝,组装了电池,初步测定了TiO2/酸性湖蓝/PoPD电极作为光阳极的光电化学电池的工作特性曲线,测得Voc=0.43V,Isc=0.378mA。     

纳米二氧化钛接枝PMMA/PBMA共聚物的表面改性

以羟丙基甲基纤维素(HPMC)对纳米TiO2进行包覆,然后再将纤维素与甲基丙烯酸甲酯/甲基丙烯酸丁酯(MMA/BMA)进行接枝共聚合,对纳米TiO2的进行表面修饰,对复合粒子进行了表征并观察了粒子的形貌.分析表明在纳米TiO2粒子的表面接枝上了MMA/BMA的共聚物;经过处理的纳米粒子的表面均匀地包覆了一层聚合物;改性后的复合纳米粒子TiO2/HPMC-g-PMMA/PBMA的热分解温度比复合物HPMC-g-PMMA/PBMA的热分解温度高56.9 K.     

窑洞建筑气凝胶复合保温材料制备表征研究

为了解决常规纤维素气凝胶物理性能不足的问题,提高保温材料隔热性能,利用TiO2纳米颗粒对纤维素气凝胶实施改性处理,制备TiO2/纤维素气凝胶复合保温材料,并从微观形貌、力学性能和导热性能三个方面对该材料加以表征。经实验发现,TiO2/纤维素气凝胶复合保温材料的压缩强度和弹性模量均显著优于单纯纤维素气凝胶,且热导率系数符合现行国家标准,可用于窑洞建筑的保温设计。     

纳米TiO_2-Pt修饰电极上甲醇的电催化氧化研究

用电化学法合成前驱体Ti(OEt)4,经直接水解法制备纳米TiO2膜,通过直接在纳米TiO2膜上电沉积Pt微粒得到纳米TiO2 Pt复合催化电极。扫描电子显微镜(SEM)和X射线衍射(XRD)分析结果表明,纳米TiO2的晶形为锐钛矿型,粒径约30nm,电沉积纳米Pt粒子(平均粒径约60nm)均匀地分散在纳米TiO2膜表面。循环伏安和计时电位测试表明,纳米TiO2 Pt修饰电极对甲醇的电氧化具有高催化活性和稳定性,Pt载量为0 68mg/cm2时,室温下甲醇氧化电流达到190mA/cm2,是纯Pt电极上的7 6倍。     

铜修饰微弧氧化二氧化钛网电极三维光电催化研究

实验采用微弧氧化技术制备了负载Cu2+的二氧化钛/钛(TiO2/Ti)网电极,考察了微弧氧化电解液浓度、光电催化电解质初始浓度、电解间距、外加电压对亚甲基蓝三维光电催化的脱色情况。结果表明,在6g/L的Na3PO4溶液中微弧氧化5min制备TiO2/Ti网电极的光催化效果最高达到25.3%;采用微弧氧化负载Cu2+法修饰TiO2/Ti网电极,当电解液中Cu2+的浓度为0.01mol/L,微弧氧化时间7min时制备的负载Cu2+的TiO2/Ti网电极,在三维光电催化体系为5mg/L的亚甲基蓝,0.01mol/L的硫酸钠溶液,1.5cm的电解间距,3.0V的外加电压以及pH为5的情况下,光电催化对亚甲基蓝的脱色率达到46.2%。     

TiO_2/沸石与活性炭三维粒子电极体系光电催化研究

采用溶胶-凝胶法制备沸石负载TiO2(TiO2/沸石)。将TiO2/沸石与活性炭按照不同比例混合为粒子电极,采用钛网作为主电极,硫酸钠溶液为助电解质,紫外灯为光源建立了三维电极光电催化体系,处理亚甲基蓝模拟废水。实验表明:当电极间距为4.0 cm、TiO2/沸石∶活性炭=2∶3、亚甲基蓝的初始浓度为3 mg/L,灯距为10 cm、电压为2.0 V、电解质浓度为0.04 mol/L、初始p H=6.0,光催化降解效率可达49.5%。三维电极光电催化效果优于二维电极光电催化与光催化效果。Fe3+离子掺杂提高了体系的光电催化效率,最大光电催化效率可达53.3%。     

电合成法制备纳米材料及纳米材料电极上的电催化合成

通过电化学合成前驱体直接水解法制备纳米TiO2 粉体和纳米TiO2 膜电极。用循环伏安法、循环方波伏安法和电解合成法研究了纳米TiO2 膜电极对有机合成反应的电催化活性。发现纳米TiO2 膜电极在 0 2～ - 1 2V扫描电位区间有两对氧化还原峰 (峰电位Epc1=- 0 5 6V ,峰电位Epc2 =- 0 95V ,扫描速度 10 0mV·s-1) ,具有异相氧化还原催化行为。电解结果表明 ,纳米TiO2 膜中的Ti(Ⅳ ) /Ti(Ⅲ )氧化还原电对作为媒质 ,异相间接电还原硝基苯为对氨基苯酚 (收率91 6 % ,电流效率 95 2 % )和草酸为乙醛酸 (收率 96 5 % ,电流效率 90 % )。     

乳糖诱导E.coli发酵生产FAD为辅基的葡萄糖脱氢酶

黄素腺嘌呤二核苷酸（FAD）为辅基的葡萄糖脱氢酶（FAD-GDH,EC1.1.5.9）,具有辅基结合紧密、催化效率高的优点,可替代目前诊断用葡萄糖氧化酶应用于血糖指标的临床生化检测。本文选取Burkholderia cepacia的葡萄糖脱氢酶基因（gdh）构建表达质粒pTrc99a-gdh,转化E. coli BL21(DE3)。异丙基硫代半乳糖苷（IPTG）诱导发酵,通过酶活测定及聚丙烯酰胺凝胶电泳分析,获得可溶性表达的FAD-GDH,分子量约为60000。利用乳糖替代IPTG作为诱导剂,摇瓶水平初步探索诱导条件,酶活达到994U/L。7.5L发酵罐放大培养该菌,采用梯度流加补料策略,分阶段温度控制,并采用不同的乳糖流加速率进行诱导。当采用0.3mL/min的乳糖流加速率时,酶活达22200U/L,菌体量达69.48g/L。经过镍柱层析,最终获得纯酶的比酶活104.5U/mg。为医用诊断原料用酶葡萄糖脱氢酶新酶种的工业化生产提供借鉴。     

反胶束法制备纳米氧化锌及其在葡萄糖生物传感器中的应用

采用琥珀酸-2-乙基己基磺酸钠/环己烷反胶束体系制备纳米ZnO,并以此ZnO为载体固定葡萄糖氧化酶,用戊二醛交联制作成葡萄糖氧化酶电极. 实验结果表明,此酶电极表现出对葡萄糖溶液浓度的优良响应,线性范围在1′10-5~3′10-3 mol/L,响应灵敏度约为6 mA/(cm2×mmol/L),表观米氏常数为2.57 mmol/L. 还研究了温度和溶液pH值对电极电流响应的影响.     

Carbon/polymer composite counter‐electrode application in dye‐sensitized solar cells

Carbon black was embedded in mixtures of poly(ethylene oxide) and poly(vinylidene fluoride–hexafluoropropylene) to make a carbon/polymer composite slurry, which was deposited onto a transparent conducting glass substrate by a doctor‐blade coating for application in dye‐sensitized solar cells (DSSCs) as a counter‐electrode (CE) material. The experiments indicated that the photovoltaic parameters of the DSSCs were strongly dependent on the carbon concentration in the slurry. The device with a carbon CE whose mass ratio was 1 : 1 (mass ratio = carbon black mass to polymer mass) exhibited an overall energy conversion efficiency of 4.62%; this was comparable to that of a device with platinum as a CE (5.32%) under the same test conditions. The better electrocatalytic activity of CE‐1.0 (where 1.0 indicates the mass ratio of carbon black to polymer) for the reduction of triiodide resulted a higher performance of the DSSC with such a CE. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Self-assembly electrode based on silver nanoparticle toward electrogenerated chemiluminescence analysis of glucose

Electrogenerated Chemiluminescence (ECL) involves applying a certain electric potential to a chemical reaction, resulting in the oxidation or reduction of the substance which reacts to produce light. We determined the amount of glucose by its reaction to glucose oxidase (GO _X ) on the surface of the proposed modified electrode, which results hydrogen peroxide (H₂O₂) as side product. After that the reactions between luminol and H₂O₂ under oxidizing conditions generate dependent light which can be used to analyze. In the current article at first we proposed a convenient method to obtaining a self-assembly modified electrode. A nano based modified glassy carbon (GC) electrode (Glucose oxidase/Ag nanoparticles/cysteamine (CA)/p-aminobenzene sulfonic acid/GC electrode) was prepared, and the ECL behavior of luminol in the presence of glucose was examined. Compared to the bare GC electrode, the modified electrode incorporating glucose oxidase significantly enhanced the response of the ECL biosensor to glucose due to the enhanced specificity of the modified surface to enzymatic reaction, and the sensitivity of the luminol ECL reaction. Under optimal conditions, the electrode was established to respond linearly to glucose in the concentration range 5.0×10^?7 to 8.0×10^?3 mol/L, and the detection limit was established to be a glucose concentration of 4.0×10^?8 mol/L.     

Preparation and characterization of poly(o‐anisidine) with the influence of surfactants on stainless steel by electrochemical polymerization as a counter electrode for dye‐sensitized solar cells

Efficient fast electron transfer from counter electrode to an electrolyte is a key process during the operation of dye‐sensitized solar cells (DSSCs). We introduce a surfactants assisted electro‐polymerized poly(o‐anisidine) (POA) counter electrodes (CE) for DSSCs. Commencing the electrochemical impedance spectroscopy, the POA/sodium dodecyl sulphate (SDS) CE exhibited very low series and charge‐transfer resistance. This is due to high electrocatalytic activity confirmed by cyclic voltammetry, surface area and the conductivity of the stainless steel film. The photovoltaic performance of POA/SDS counter electrode shows an energy conversion efficiency of 2.5% under 1 sun illumination. Short‐term stability test for POA/SDS point out that CE have almost uphold its initial performance. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42310.     

Graphene wrapped copper–nickel nanospheres on highly conductive graphene film for use as counter electrodes of dye-sensitized solar cells

A novel architecture of graphene wrapped copper–nickel (Cu–Ni) nanospheres (NSs)/graphene film was proposed to be TCO- and Pt-free counter electrode (CE) with high electrocatalytic activity for dye-sensitized solar cells (DSSCs). The novel architecture CE is composed of highly conductive graphene film, Cu–Ni alloy NSs and the wrapping graphene on the surface of alloy NSs. The graphene film as an electrically conductive layer was synthesized by chemical vapor deposition (CVD) on the insulating SiO₂ substrate, and graphene wrapped Cu–Ni alloy catalyst NSs on the graphene film were in situ formed by the reduction of Cu–Ni acetate and graphene growth using CVD. The graphene wrapped Cu–Ni NSs/graphene film CE shows much superior electrocatalytic activity, compared with graphene film, and the power conversion efficiency of 5.46% was achieved in DSSC devices, which is close to that of Pt/FTO electrode (6.19%). Therefore, the novel architecture of graphene wrapped Cu–Ni NSs/graphene film CE may be used as Pt- and TCO-free CEs for low-cost, high performance DSSCs.     

An efficient thiolate/disulfide redox couple based dye-sensitized solar cell with a graphene modified mesoscopic carbon counter electrode

Graphene sheet is used to modify mesoscopic carbon materials through electrostatic induced self-assembly and applied as a Pt-free counter electrode (CE) in a thiolate/disulfide redox couple based dye-sensitized solar cell (DSSC). The electrochemical characterization are carried out with Electrochemical impedance spectroscopy and Tafel polarization, which indicates that the catalytic activity of mesoscopic carbon CE is dramatically improved and the mass transport of the thiolate/disulfide redox couple in the pores of mesoscopic carbon electrode was accelerated via being modified with graphene. As a result, efficiency up to 6.55% is obtained, which is increased by 35% than that of the normal mesoscopic carbon CE. It could be expected that Pt-free graphene modified mesoscopic carbon materials promise tremendous potential for iodine-free DSSC.     

A facile one-step synthesis and fabrication of hexagonal palladium-carbon nanocubes (H-Pd/C NCs) and their application as an efficient counter electrode for dye-sensitized solar cell (DSSC)

Hexagonal palladium-carbon nanocubes (H-Pd/C NCs) were prepared using a simple one-step chemical synthesis protocol and subsequently the prepared materials were used as the counter electrode (CE) in dye sensitized solar cell (DSSC) to replace the platinum (Pt) electrode. The H-Pd/C NCs were characterized by a variety of suitable analytical techniques including powder X-ray diffraction (PXRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and Brunauer–Emmett–Teller (BET) analysis to evaluate the crystalline, structural, morphological, compositional, chemical state and surface area. The BET nitrogen adsorption /desorption analysis shows that the as-prepared H-Pd/C NCs sample had a large surface area (568.8 m² g⁻¹) with average pore size of ∼3 nm. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) analyses indicate that the H-Pd/C NCs have low charge-transfer resistance on the electrolyte/electrode interface and high electrocatalytic activity for the reduction of triiodide to iodide redox electrolyte and hence it is used as a CE in DSSC. The H-Pd/C NCs showed an overall power conversion efficiency (PCE) of 4.1% which performance is comparable with the conventional Pt CE (4.0%) under the identical condition.     

贮氢合金电极在山梨醇制备中的应用

用贮氢合金作催化还原电极恒电位电解葡萄糖 ,得出合金的表面处理及电极的活化可提高山梨醇电流效率至 80 %以上的结论。同时贮氢电极与Pb电极及发泡Ni电极作了对比 ,发现电解葡萄糖制备山梨醇过程中 ,贮氢电极是较好的还原电极。用贮氢电极 (2 )做阴极 ,30℃ ,电流密度为 80 0mA/dm2 ,葡萄糖溶液及硫酸钠支持电解质浓度均为 0 .5mol/L ,pH =8的条件下 ,电解葡萄糖制山梨醇电流效率高达 94% ,葡萄糖转化率达 80 %以上。     

重组基因工程菌几丁质酶C的可溶性表达研究

在不同培养温度条件下对产几丁质酶C的基因工程菌BL21（DE3）进行诱导,使其表达可溶性蛋白.随后在较佳培养温度诱导条件的基础上向培养基中添加不同浓度的甘油,甘氨酸,山梨醇/甜菜碱等成分来更进一步的提高几丁质酶C的可溶性表达.其结果是在25℃诱导条件下,以添加2g/L葡萄糖的LB培养基作为基础培养基进行培养,在基础培养基中添加3g/L甘油的总酶活最高,达到了18.17 U/mL,较之仅含2g/L葡萄糖的LB培养基在37℃及25℃诱导培养条件下酶活力分别提高了41.6％和20.3％;添加0.3％甘氨酸约90％的可溶性几丁质酶表达到了胞外,胞外酶活达到14.68 U/mL;添加0.5 M山梨醇/2.5 mM甜菜碱工程菌胞内酶活达到最高,为8.43 U/mL.结果表明适当降低工程菌诱导表达时的培养温度提高了几丁质酶C的可溶性表达,在较佳温诱导表达的基础上向培养基中添加不同浓度的甘油,甘氨酸,山梨醇/甜菜碱更进一步的提高了几丁质酶C的可溶性表达.