酸溶液中氧在Ti/RuO2+TiO2电极上阳极析出动力学与机理研究

本文通过在酸溶液中Ti/RuO_2+TiO_2电极上氧阳极析出动力学的研究, 表明酸溶液中氧阳极析出的极化曲线同样具有两Tafel区. 低极化区的Tafel斜率? φ/?lgi=2.303RT/(1+β)F(即0.039 V, 其中β=0.5). 高极化区为?φ/?lg i=2.303RT/βF(即0.118 V). 在前一区域内氧析出反应对于水分子活度(α_w)的反应级数为4, 即i～α_w~4. 后一区域内则为2, 即i～α_w~2. 实验结果表明, 酸溶液中上述电极上氧阳极析出是按反应序列(1)、(2)进行的     

钛基导电氧化物电极上氧的阳极析出动力学与机理研究

本文通过在碱溶液中Ti/RuO_2+TiO_2(A)和Ti/SnO_2+CuCo_2O_4(B)电极上氧阳极析出动力学的对比研究, 表明这两类电极上氧的极化曲线均有两Tafel区。低极化区的Tafel斜率为0.039V(简称b_1区); 高极化区为0.120V(简称b_2区)。在A电极上b_1区i～a_W·a_(OH~-); b_2区i～a_W(浓碱溶液)或i～a_(OH)~(0.1～0.5)(稀碱溶液),在B电极上b_1区i～a_(OH~-); b_2区i～a_(OH~-)~(0.39)(浓碱溶液);或i～a_(OH~-)(稀碱溶液), 实验结果表明, 虽然这两类电极上氧阳极析出过程都由第二电子转移步骤控制, 但其机理不同, 前者是由水分子参加, 控制步骤为RuO_2·OH_(ads)+H_2O ~(rds)→ RuO(OH)~+_3+e后者则为 (SOH)~(n+)_(ads) ~(rds)→ (SOH)~((n+1)+)_(ads)+e它们与PbO_2、Pt和低碳钢上机理有些不同~[1,2]。     

酸溶液中氧在Ti/RuO_2+TiO_2电极上阳极析出动力学与机理研究

本文通过在酸溶液中Ti/RuO_2+TiO_2电极上氧阳极析出动力学的研究,表明酸溶液中氧阳极析出的极化曲线同样具有两Tafel区.低极化区的Tafel斜率?/?lgi=2.303RT/(1+β)F(即0.039V,其中β=0.5).高极化区为?/?lg i=2.303RT/βF(即0.118V).在前一区域内氧析出反应对于水分子活度(α_w)的反应级数为4,即i～α_w~4.后一区域内则为2,即i～α_w~2.实验结果表明,酸溶液中上述电极上氧阳极析出是按反应序列(1)、(2)进行的     

Pr-PVP掺杂Ti/PbO_2电极制备及其在有机物降解中的应用

在Ti基体上,采用电沉积法制备了镨(Pr)和聚乙烯吡咯烷酮(PVP)掺杂的Ti/SnO_2-Sb_2O_3/Pr_2O_3-PVP-PbO_2电极.SEM测试显示,Ti/SnO_2-Sb_2O_3/Pr_2O_3-PVP-PbO_2电极表面颗粒细化,镀层结构更加致密和均匀.XRD分析说明掺杂可以使电极的表面颗粒变小.循环伏安(CV)测试表明,共掺杂改性后的电极电催化活性明显提高.强化寿命测试显示Ti/SnO_2-Sb_2O_3/Pr_2O_3-PVP-PbO_2电极稳定性更好,使用寿命更长.将所制备的电极应用于甲基蓝(MB)模拟染料废水的降解测试,与常规的Ti/PbO_2电极相比,Ti/SnO_2-Sb_2O_3/Pr_2O_3-PVP-PbO_2电极对甲基蓝具有更好的脱色率和COD除去率.降解120 min后,对30 mg·L~(-1)甲基蓝的去除率可达99%,对COD去除率为87.9%.     

Co_3O_4/Ti电催化膜电极制备及其苯甲醇催化氧化性能

本文采用浸渍涂覆法制备出多孔Ti负载纳米Co_3O_4电催化膜电极(Co_3O_4/Ti),以该膜电极为阳极,辅助电极为阴极,构建电催化膜反应器(electrocatalytic membrane reactor,ECMR)用于可控催化氧化苯甲醇制备苯甲醛和苯甲酸,并考察了Co_3O_4/Ti膜电极结构、电化学性能以及ECMR不同操作参数对苯甲醇转化率、苯甲醛和苯甲酸选择性的影响.结果表明,负载Co_3O_4纳米颗粒可以显著提高Ti膜电极的电化学性能和催化活性.在常温常压下,当反应物苯甲醇浓度为10 mmol·L~(-1),pH为7.0,停留时间为5.0 min,电流密度为2.5 mA·cm~(-2)时,苯甲醇的转化率达到49.8%,苯甲醛选择性为51.5%,苯甲酸选择性为23.6%.     

Fe_3O_4/MnO_2掺杂石墨烯基分子印迹杂化材料用于水环境中17β-雌二醇的电化学传感检测

采用可逆加成-断裂链转移(Reversible addition fragmentation chain transfer,RAFT)分子印迹技术,以内分泌干扰物17β-雌二醇(17β-estradiol,17β-E_2)作为模板分子,以甲基丙烯酸(Methacrylic acid,MAA)为功能单体,二乙烯基苯(Divinyl benzene,DVB)为交联剂,Fe_3O_4/MnO_2掺杂的石墨烯(RGO)为载体,成功制备了Fe_3O_4/MnO_2掺杂石墨烯基分子印迹杂化材料(Fe_3O_4/MnO_2-MIP@RGO),构建了基于Fe_3O_4/MnO_2-MIP@RGO修饰电极的分子印迹电化学传感器。研究结果表明,Fe_3O_4/MnO_2-MIP@RGO修饰电极对17β-E_2的线性响应范围为4.0 nmol/L~0.8μmol/L(R=0.9852),检出限为47.2 pmol/L(3σ),相对标准偏差(RSD)为2.1%~2.5%。本研究为水环境中痕量17β-E_2的特异性识别检测提供了一种简单、高效、经济的分析方法。     

铈改性纳米Ti/SnO_2-Sb_2O_3电极的制备及催化性能

以SnCl_4·5H_2O,Sb_2O_3和Ce(NO_3)_3·6H_2O为前驱体,采用溶胶-凝胶法制备了Ce改性Ti/SnO_2-Sb_2O_3电极。通过对Ce改性Ti/SnO_2-Sb_2O_3电极的析氧电位的测试及油田废水降解情况的考察,优化了稀土的掺杂量和热处理方法;分析了电极的电催化氧化能力。借助SEM,EDX和XRD等检测手段对所制备电极的表面形貌、元素组成、晶体结构进行了表征和分析。结果表明:最优掺杂比为Sn∶Sb∶Ce=100∶10∶2.5(摩尔比),最优热处理方法为方法二,此电极对目标有机物COD去除率达到91.2%,发现Ce的掺杂有利于电极催化性能的提高。     

La-Ti/SnO2-Sb/RuO2-Co电极制备及其处理垃圾渗滤液研究

以纯钛为基体材料,并以热氧化的方式制备La-Ti/SnO_2-Sb/RuO_2-Co电极,采用X-射线衍射仪(XRD)、扫描电子显微镜(SEM)及X-射线能量色散谱(EDS)对电极涂层表面形貌和晶体结构进行表征。采用制备的La-Ti/SnO_2-Sb/RuO_2-Co电极作为阳极,不锈钢为阴极,构建电化学反应器,对老龄垃圾渗滤液进行降解。结果表明在电流密度为65 mA/cm~2、Cl-浓度为4 500 mg/L、初始pH=9和反应时间为6 h的最佳反应条件下,La-Ti/SnO_2-Sb/RuO_2-Co电极对NH_3-N和COD的去除率分别达到86.5%、61%。     

Composite Electrodeposited PbO_2/Co_3O_4 on a Ti Substrate as Positive Electrode Materials for a Hybrid Supercapacitor

PbO_2/Co_3O_4 composites were prepared on a Ti substrate by means of a composite electrodeposition method in Pb~(2+) plating solution containing dissolved nano-Co_3O_4 particles. X-ray diffraction(XRD), scanning electron microscopy(SEM), energy dispersive spectrometry(EDS) and transmission electron microscopy(TEM) were used to characterize the chemical composition and morphology of the PbO_2/Co_3O_4 composites. The electrochemical and capacitance performance of the composites were investigated by cyclic voltammetry(CV), charge-discharge tests and electrochemical impedance(EIS). The results indicate that the composites comprise rutile phase Co_3O_4 and β-PbO_2. In addition, the surface of the composite electrode is rough and porous. The PbO_2/Co_3O_4 composites exhibit a high specific capacitance up to 215 F/g, which is ten times higher than that of the pure-PbO_2 and two times higher than that of the pure-Co_3O_4 in 1 mol/L NaOH electrolytes.     

Sno2+Sb203中间层的制备条件对Ti/SnO2+Sb2O3/PbO2阳极性能的影响

研究了聚合前驱体制备的SnO2+Sb2O3中间层的焙烧温度、锑含量对Ti/SnO2+Sb2O3/PbO2阳极性能的影响. 用XRD、ESEM和探针法对锡锑中进行了表征,应用阳极寿命快速检测法测定了Ti/SnO2+Sb2O3/PbO2电极在1.0 mol/L H2SO4溶液中的寿命,并用极化曲线和电荷容量表征了锡锑中间层对钛基PbO2阳极性能的影响. 实验结果表明,聚合前驱体制备中间层的焙烧温度和锑含量对Ti/SnO2+Sb2O3/PbO2电极的寿命和性能有显著的影响. 在锡锑中间层的制备温度为500 ℃、n(Sn):n(Sb)=9:1时,制得的Ti/SnO2+Sb2O3/PbO2电极用阳极寿命快速检测法测得的电极寿命达30h,具有良好的稳定性.     

Ti／SnO2＋Sb2O3／PbO2阳极的性能研究

以ＳＥＭ、ＥＤＳ和ＸＲＤ研究Ｔｉ／ＳｎＯ２＋Ｓｂ２Ｏ３／ＰｂＯ２阳极，测定该阳极在１ｍｏｌ／ＬＨ２ＳＯ４中的使用寿命及其电化学参数ａ，ｂ，ｉ０并用双位垒模型讨论了其动力学参数。结果表明该电极具有优良的电化学性能和较长的使用寿命。     

金属氧化物对聚丙烯膨胀阻燃体系阻燃性能的影响

将Bi2O3、Sb2O3、SnO2添加到聚磷酸铵(APP)和双季戊四醇(DPER)膨胀型阻燃聚丙烯(PP)体系中,采用氧指数(OI)、热分析(TGA)、热红联用(TG-FTIR)和扫描电镜(SEM),考察它们对膨胀阻燃体系的催化协效作用,探讨其作用机理.结果表明,3种金属氧化物在适量的添加下都可以提高体系的氧指数.TG结果表明,Bi2O3的加入可以提高膨胀炭层在高温时的热稳定性,增加高温时残余物的量;TG-FTIR结果显示添加Bi2O3后,膨胀阻燃剂在热分解过程中,气体的释放过程发生了改变.膨胀炭层的SEM图表明,Bi2O3可以改善膨胀炭层的形貌,提高炭层的隔热隔质性能.0.1 wt%的Bi2O3和1 wt%的纳米黏土复配用于膨胀阻燃体系中,可以在阻燃剂添加20份下,样品氧指数达到28.3;在阻燃剂添加25时,样品(3.2 mm)通过UL-94 V-0级.0.1 wt%的Bi2O3和1 wt%纳黏粘土的添加,还可以提高体系的力学性能.     

3-甲基吡啶电氧化合成烟酸的研究

在有阳离子交换膜的电解槽内,通过稳态极化曲线测量,考察了3-甲基吡啶在Pt电极和PbO2/Ti电极上的电极反应,发现PbO2/Ti电极对生成烟酸有电催化作用.通过高效液相色谱分析,进一步考察了各种因素对电流效率的影响.     

一维纳米Co_3O_4,Ag/Co_3O_4及CuO/Co_3O_4的合成与电催化性能(英文)

采用水热合成法制备了Co3O4及复合Ag/Co3O4、CuO/Co3O4一维纳米产品。用XRD,FE-SEM和TEM手段对产品进行了表征。采用循环伏安法研究了合成产品修饰的玻碳电极在碱性溶液中对对硝基苯酚的电催化还原性能。与裸玻碳电极相比,1mmol·L-1的对硝基苯酚在用Co3O4、特别是CuO/Co3O4修饰的玻碳电极上还原的峰电流明显增大,用Ag/Co3O4(Ag/Co原子比分别为1∶5和2∶5)修饰的玻碳电极催化还原对硝基苯酚时,尽管还原峰电流增大不是太大,但其峰电位明显降低(分别降低0.265和0.371V)。     

Co(III)离子在二氧化铅电极上的阳极形成

文献上曾报导过Co(Ⅱ)离子具有加速PbO_2电极上氧阳极析出过程的作用,并表明当Co(Ⅱ)离子存在时,氧的析出过程有可能通过表面吸附的高价钴氧化物氧化水分子而形成.本文通过浓硫酸溶液中Co(Ⅱ)阳极氧化为Co(Ⅲ)以及O_2阳极析出动力学的研究,表明了O_2的析出和Co(Ⅲ)的形成是通过吸附在电极表面的高价钴(Ⅳ)的OH 基配合物分别氧化水分子和Co(Ⅱ)离子形成的,它与Cr(Ⅲ)、Mn(Ⅱ)离子的阳极氧化过程相类似,而不是通过Co(Ⅱ)离子直接放电形成的.本文利用文献所述的研究方法.在固定硫酸浓度(3.4mol·kg~(-1))下,研究CoSO_4浓度(0.05—0.35mol·drn~(-3))对于O_2和Co(Ⅲ)阳极形成过程分别的影响.在固定CoSO_4(0.2mol·     

The design and fabrication of Co_3O_4/Co_3V_2O_8/Ni nanocomposites as high-performance anodes for Li-ion batteries

The Co_3O_4/Co_3V_2O_8/Ni nanocomposites were rationally designed and prepared by a two-step hydrothermal synthesis and subsequent annealing treatment. The one-dimensional(1D) Co_3O_4 nanowire arrays directly grew on Ni foam, whereas the 1D Co_3V_2O_8 nanowires adhered to parts of Co_3O_4 nanowires.Most of the hybrid nanowires were inlayed with each other, forming a 3D hybrid nanowires network.As a result, the discharge capacity of Co_3O_4/Co_3V_2O_8/Ni nanocomposites could reach 1201.8 mAh/g after100 cycles at 100 mA/g. After 600 cycles at 1 A/g, the discharge capacity was maintained at 828.1 mAh/g.Moreover, even though the charge/discharge rates were increased to 10 A/g, it rendered reversible capacity of 491.2 mAh/g. The superior electrochemical properties of nanocomposites were probably ascribed to their unique 3D architecture and the synergistic effects of two active materials. Therefore, such Co_3O_4/Co_3V_2O_8/Ni nanocomposites could potentially be used as anode materials for high-performance Li-ion batteries.     

水热-热解法制备具有一维结构的Co3O4多晶

采用温和的水热-热解法, 在一定温度下, 通过调节Na2CO3溶液和可溶性钴盐的摩尔比控制产物的形貌, 得到具有一维结构的水热产物. 以该产物为前驱体制备了具有一维结构的Co3O4多晶. 以六次甲基四胺、尿素等代替Na2CO3溶液作为沉淀剂, 均得到了一维纳米结构的Co3O4, 表明CO2-3在水镁石CoO2层间的嵌入是得到一维结构水热产物的关键.     

羟基新戊醛在Ti/Sb2O5-SnO2电极上的电氧化研究

在以质子交换膜为隔膜的电解槽内, 以硫酸为支持电解质, 羟基新戊醛为原料, 在Ti/Sb2O5-SnO2电极上直接电氧化制取羟基新戊酸. 线性扫描伏安曲线显示, 加入羟基新戊醛使氧化电流密度明显提高, 表明Ti/Sb2O5-SnO2电极对羟基新戊醛氧化有电催化作用. 通过恒电位电解实验研究羟基新戊醛浓度、pH、温度及阳极电位对生成羟基新戊酸选择性和电流效率的影响, 结果表明, pH对选择性和电流效率影响最大.     

Effect of dissolved CO2 on the potential stability of all-solid-state ion-selective electrodes.

The influence of dissolved CO2 on the potentiometric responses of all-solid-state ion-selective electrodes (ISEs) was systematically examined with four different types of electrodes fabricated by pairing pH-sensitive and pH-insensitive metal electrodes (Pt and Ag/AgCl, respectively) with pH-sensitive and pH-insensitive ion-selective membranes (H+-selective membrane based on tridodecylamine and Na+-selective membrane based on tetraethyl calix[4]arenetetraacetate, respectively). The experimental results clearly showed that the carbonic acid formed by the diffused CO2 and water vapor at the membrane/metal electrode interface varies the phase boundary potentials both at the inner side of the H+-selective membrane (deltaE(in)mem) and at the metal electrode surface (deltaEelec). The potential changes, deltaE(in)mem and deltaEelec, occurring at the facing boundaries, are opposite in their sign and result in a canceling effect if both the membrane and metal surface are pH-sensitive. Consequently, the H+-selective membrane coated on a pH-sensitive electrode (Pt) tends to exhibit a smaller CO2 interference than that on a pH-insensitive electrode (Ag/AgCl). When the all-solid-state Na+ and K+ ISEs were fabricated with both pH-insensitive metal electrode and ion-selective membrane, they did not suffer from CO2 interference. It was also confirmed that plasticization of the PVC leads to increased CO2 permeation. Various types of intermediate layers were examined to reduce the CO2 interference problem in the fabrication of H+-selective all-solid-state ISEs. The results indicated that the H+-selective electrode needs an intermediate layer that maintains a constant pH unless the carbonic acid formation at the interfacial area is effectively quenched.