金纳米颗粒修饰钛电极的制备及其对葡萄糖氧化的电催化活性

利用恒电流电沉积法,制备出金纳米颗粒修饰钛电极（Au／Ti）。利用循环伏安、电位阶跃等电化学技术,研究了碱性溶液中Au／Ti电极对葡萄糖氧化的电催化活性。与多晶金电极相比,葡萄糖在Au／Ti电极上氧化的起始电位更低、电流密度明显增加。实验表明,A11／Ti电极对葡萄糖氧化具有很高的电催化活性。对葡萄糖在Au／Ti电极上的双电位阶跃分析表明,葡萄糖在0．1mol／LNaOH溶液中的电化学氧化反应速率常数为5．79×10^4cm^3／（mol·s）。     

泡沫镍基Ni-P-W-Mo析氢电极的制备与电化学性能

以硫酸镍、次亚磷酸钠、钨酸钠、钼酸钠等为原料,采用一步恒电流电沉积法在泡沫镍基底上合成Ni-P-W-Mo析氢电极,借助X射线衍射、扫描电镜、能谱仪、X射线光电子能谱以及电化学测试等手段研究材料的表面形貌、元素组成以及电化学析氢性能。结果表明,Ni-P-W-Mo析氢电极在碱性溶液中析氢催化时有出色的催化活性和稳定性,仅需92 mV的过电位即可达到10 mA/cm²的电流密度,比Ni-P电极降低67 mV,电极的双层电容为42.98 mF/cm²,经过2 000次循环伏安(cyclic voltammetry, CV)测试后,析氢活性略微下降。Ni-P-W-Mo电极优异的催化性能可能是由于W、Mo的添加使电极的表面形貌更粗糙,电化学活性表面积和活性位点显著增加,同时自支撑电极结构可以有效降低界面传输电阻,提高电荷传输效率。     

电沉积法制备自支撑Ni-Sn-B电极的显微结构与电催化析氢性能

为开发高效稳定的析氢电催化剂,采用恒电流电沉积法在镍网基底上制备自支撑的Ni-Sn-B析氢电极,通过扫描电镜、X射线衍射仪、透射电镜、X射线光电子能谱仪和电化学工作站等对电极的形貌结构、元素组成与电催化析氢性能进行表征和测试。结果表明,Ni-Sn-B电极表面由粗糙的胞状颗粒紧密堆积而成,具有非晶态特征结构。在碱性电解质中,Ni-Sn-B电极表现出优异的催化析氢活性和稳定性,在10m A/cm²电流密度下过电位仅为63 mV,比Ni-Sn和Ni-B电极的过电位分别降低38.2%和59.1%。电极的电荷转移电阻为1.56Ω,经过5 000次CV循环和72 h电解后,仍保持非常高的析氢活性。粗糙的表面形貌及非晶态结构使电极的电化学活性表面积和催化活性位点显著增加,同时B和Sn对Ni电子结构的调控,可有效降低电荷转移阻力,从而提升电极的电催化析氢性能。     

以阵列二氧化钛纳米棒为载体制备一体化析氧电极

以碳纸为支撑体,氯铱酸为前体,利用二氧化钛纳米棒阵列作为载体,采用浸渍-热分解法成功制备IrO₂-TiO₂/C一体化析氧电极.通过扫描电镜 (SEM)、XRD、XPS和电化学方法——循环伏安 (CV)、交流阻抗 (EIS) 等手段,研究载体形貌对析氧电极性能的影响.结果表明:二氧化钛载体能有效抑制支撑体碳纸在高电位下的腐蚀,当电压为2.4 V时,极化电流才仅为13.2 mA/cm2,一体化析氧电极积分电荷由87.2 mC/cm2增至178.5 mC/cm2,电极电化学反应阻抗由3.13 Ω·cm2降低到1.62 Ω·cm2,极大地提高了析氧电极的接触面积和催化剂的电催化活性.      

CeO2对Ti基RuO2-SnO2涂层阳极电催化性能的影响

采用热分解法制备了掺杂CeO2的Ti基RuO2-SnO2涂层阳极,通过开路电位测试、循环伏安测试以及交流阻抗测试研究了所制备涂层阳极的电催化性能,并用扫描电镜观察了涂层阳极的表面形貌。结果表明,在涂层阳极中掺杂CeO2可以提高涂层阳极的电催化活性,CeO2的最佳掺杂量为0.4(摩尔分数)。涂层阳极电催化性能提高的原因在于掺杂的CeO2可以提高涂层的有效活性表面积。     

喷雾热蒸发炭膜用于二次锂离子电池负极的研究

以有机热解炭(石墨)为原料,用喷雾热蒸发法制备了用于二次锂离子电池负极的炭膜,用循环伏安法和恒电流充放电法测试了所获炭膜的电化学性能,测试结果表明,在第1循环周期中存在1个还原峰对应在电极表面形成固体电解质中间相膜;当充放电电流大小合适时,容量和每mol炭中嵌入其他物质的摩尔数(x)值都较大,基于这些实验结果,认为所获得的炭膜能用作电池负极以相对测试其他正极材料的电化学性能。     

金相组织结构对Pb-Ag-RE合金阳极电化学行为的影响

采用循环伏安法、计时电位法、Tafel测试对比研究了3种具有不同金相组织结构的Pb-AgRE阳极的析氧行为。结果表明,金相组织中不同相的含量和分布影响阳极氧化成膜,进而影响阳极电化学行为;浇铸阳极金相中含有大量的晶界和富RE二次相,这些相在极化过程中易氧化成膜,因此浇铸阳极氧化膜最厚。其中,膜层中PbO_2含量也最大,促进活性位点的生成,因而浇铸阳极析氧活性高;压延面电极膜层最薄,但压延面电极和横截面电极析氧活性相当。     

溶剂对Ti/SnO2-Sb-Nd电极性能的影响

分别以乙醇、异丙醇、正丁醇为溶剂配制涂液,采用刷涂热分解法制备了稀土Nd共掺杂的Ti/SnO2 -Sb-Nd电极.采用SEM、XRD、伏安电荷、电化学孔隙率、分形维数、降解苯酚实验等研究了溶剂对电极微观形貌、晶体结构和电化学性能的影响.结果表明:随着所用醇类溶剂的与羟基相连的碳链复杂化和延长,制得电极涂层的微观表面趋于平整,物理比表面积变小.碳链最长的正丁醇溶剂体系制得了结晶最好的SnO2电极涂层,并且有效的阻止了钛基体被氧化.按照乙醇、异丙醇、正丁醇顺序,相应的3种电极的伏安电荷分别为1.783,2.074,2.884 mC·cm-2,这表明电极的电化学活性面积依次增大;电极涂层的电化学孔隙率分别为97.78％,53.11％,51.68％;电极涂层的分形维数分别为1.892,1.978,1.968;当累积通电量为4.783 Ah ·L-1时,苯酚降解率分别达到87.49％,90.04％,91.50％,在此过程中槽压分别升高了3.94,1.48,1.44V.伏安电荷、电化学孔隙率和分形维数的变化规律有效地反映了电极的电催化氧化活性和稳定性的变化.     

Ti/SnO2-Sb:Eu3+电极制备及性能表征

以SnCl4·5H2O、Sb2O3和Eu2O3为原料,以钛片为基体,采用涂层热解法制备了Eu3+掺杂Ti/SnO2-Sb电极.研究了电极的电化学性能,对所制备的电极作LSV和Tafel曲线,以对硝基苯酚为目标降解有机物,考察了电极的电催化活性.分析Eu3+掺杂量对电极性能的影响,采用X-射线衍射(XRD)、扫描电镜(SEM)和能谱仪(EDS)等检测方法对Eu3+掺杂Ti/SnO2-Sb电极表面涂层的晶体结构、形貌和元素组成进行了研究;,发现掺杂量为1％的电极的性能最佳,此条件下得到的电极有高的析氧电位和电催化活性,以及较好的电极涂层结构和覆盖度.     

铝在室温熔盐中的电沉积

采用循环伏安法、计时电流法研究了铝在摩尔比为2∶1的AlCl3-EMIC离子液体中钨电极上的电化学还原机理和成核机理。研究表明:铝在钨极上存在欠电位沉积现象,铝的析出电位为-0.06 V,电化学反应为准可逆反应,形核过程为三维瞬时形核,半球形扩散控制长大。电沉积试验表明在电流密度为5~25 mA/cm2时镀层较致密、均匀,附着力好,纯度高。     

PEM水电解用多层钛网析氧阳极制备及性能研究

以钛网为扩散层基体,氯铱酸为前驱体,采用浸渍-热解法制备了IrO₂/Ti 析氧阳极,进一步采用热压法制备膜电极.综合扫描电镜尧循环伏安尧交流阻抗尧单池性能曲线测试及阳极寿命强化测试,研究了不同层数钛网析氧阳极对性能及寿命的影响.结果表明院与单层钛网析氧阳极比较,采用双层钛网析氧阳极,积分电荷由84.27 mC/cm2 增至153.12 mC/cm2,电极电化学反应阻抗由7.38 Ω·cm2 降低至3.03 Ω·cm2,单池性能得到提升.寿命强化测试表明,采用双层钛网析氧阳极在稳定性及寿命方面有显著提升,稳定运行时间由30 h 增加到了53 h.      

水溶液中电沉积Sm-Fe合金

Sm2Fe17是一种性能优异的永磁材料(SmFeN)的前驱体。用循环伏安法研究了三价钐(Sm(Ⅲ))和二价铁(Fe(Ⅱ))在含甘氨酸的水溶液中的电化学行为,在Pt电极上,Fe(Ⅱ)一步还原为Fe,Sm(Ⅲ)能被Fe(Ⅱ)诱导共沉积。在水溶液中成功电沉积出Sm-Fe合金。研究了pH和电流密度对镀层组分的影响,在电流密度为40mA.cm-2时,随着pH升高,镀层中Sm含量增加,在pH=4.5时,随着电流密度的增加,镀层中Sm含量增加。电子显微镜(SEM)显示镀层表面是紧密一致的。镀层在热处理前是非晶态Sm-Fe合金和微晶Fe的混合相,经750℃热处理后,镀层转化为Fe和Sm-Fe合金的混合相。     

Preparation of Ti-based Yb-doped SnO2–RuO2 electrode and electrochemical oxidation treatment of coking wastewater

In this study, the Ti/SnO₂–RuO₂ electrodes with different Yb contents were prepared by sol–gel method and thermal decomposition method, and the surface morphology and crystal structure of the electrodes were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM) and X-ray diffraction (XRD), the electrochemical properties of the electrodes were tested by linear sweep voltammetry (LSV) and cyclic voltammetry (CV). The electrochemical oxidation device was constructed with Yb-doped Ti/SnO₂–RuO₂ electrode as the anode and titanium plate as the cathode, and the electrochemical oxidation effect and product changes of the anode on coking wastewater were investigated. The results show that the surface of the electrode is flat with high crystallinity of SnO₂ and RuO₂ crystals at 1.5% Yb doping, and the LSV and CV curves indicate that the Yb doping of 1.5% increases the oxygen precipitation potential and electrocatalytic oxidation activity of the electrode. When the electrode with Yb doping of 1.5% is the anode with current density of 10 mA/cm² electrochemical oxidation time of 30 min, the electrode can remove chemical oxygen demand (COD) up to 85.06%, total organic carbon (TOC) up to 60.59% and UV₂₅₄ from 1.594 to 0.507 for coking wastewater. Gas chromatography (GC–MS), UV–vis and three-dimensional fluorescence results of coking wastewater before and after treatment show that large toxic substances in coking wastewater are degraded to low toxic organic substances, and most soluble organic substances are degraded and transformed. This study provides the possibility of basic research for the engineering practice of electrochemical oxidation for the treatment of coking wastewater.     

超混沌电流对金属锰电解阳极电位振荡的调控

金属锰湿法电冶过程是一个典型的远离平衡态的非线性体系,直流作用下会出现电化学振荡、金属分形等非线性行为而引发体系额外的能耗。本文提出一种超混沌电流电解的新模式,通过引入超混沌电路代替原有直流电源来实现。超混沌电流作用下,采用恒电流极化曲线、阳极极化曲线、塔菲尔测试等分析方法和X射线衍射分析、扫描电子显微镜的表征方法,研究铅合金阳极电化学振荡行为与阳极沉积的锰氧化物之间的关联。研究结果表明,在电流密度为350 A·m?2恒电流极化30 min后,超混沌电流极化作用下电位振荡的平均振荡周期较直流极化提高5.6 s,平均振幅降低 38 mV;超混沌电流作用下阳极生成的MnO₂,其表面较为致密平整,在一定程度上可以提高铅合金阳极析氧反应活性和耐腐蚀性。综合分析可知,将超混沌电流运用于金属锰电解过程,可以实现对阳极电化学振荡的有效调控,为进一步降低电解过程能耗和污染排放提供新思路。      

V含量对(Ti,V)C35CrMo钢结硬质合金组织与力学性能的影响

用原位烧结法制备了不同V与Ti原子比(0,0.2,0.4,0.8)的(Ti,V)C35CrMo钢结硬质合金.研究了V含量对钢结硬质合金组织及力学性能的影响.用SEM 观察试样的微观组织特征、断口形貌和磨损形貌.结果表明:V含量影响钢结硬质合金硬质相的形态、大小、体积分数,进而影响合金的力学性能.V与Ti的原子比为0.2时硬质相最小;随着V含量增加,硬质相趋于圆整、并增大.断口形貌特征为硬质相解理、基体准解理及韧窝.基体形变磨损和硬质相脱落是钢结硬质合金的磨料磨损机理.V与Ti的原子比为0.2时抗弯强度及耐磨性最高.     

Stability and Durability Study of Nano Pt Coated Titanium for Electrode Application

The present work involves development of noble metal nanoparticle coated Ti based electrode for application in severe corrosive environments. The etched Ti substrate was coated with noble metal nanoparticle via a seed mediated hydrothermal reduction method. Advanced surface characterization techniques elucidated that this two step synthesis method generated a uniform and highly dispersed nanoparticle coating on Ti which is essential for application in severe corrosive medium. The enhanced activity for methanol electro-oxidation compared to polycrystalline Pt proved the excellent electrocatalytic activity of as synthesized Pt nanoparticles coated Ti electrode. The adhesion strength of the coating on the Ti substrate was found to be excellent with a rank of 5A as per ASTM standard. The long term durability of Pt nanoparticles coated big cylindrical Ti mesh with 164 cm² surface area was tested by employing it as anode for electro-oxidation of Ce in 11.5 M nitric acid under an applied operational current density of 9 mA/cm² for 1000 h. Only 1 V increment was observed even after 1000 h confirming the excellent durability of this electrode. SEM and elemental mapping of the surface of coated electrode after 1000 h exposure in severe corrosive nitric acid further confirmed uniform dispersion of Pt on the surface and absence of delamination.     

新型陶瓷材料Ti3SiC2制备技术的研究进展

Ti3SiC2兼有金属和陶瓷的许多优异性能。因此，Ti3SiC2在作为高温结构材料、自润滑材料以及电极材料等方面具有十分广阔的应用前景。本文重点介绍了Ti3SiC2的各种制备技术，并指出了各自的应用特点和存在的主要问题以及未来的研究方向。     

Effect of Synergistic Anticorrosion Treatments on Cycling Stability of Mg-Based Hydrogen Storage Electrode

In this paper, any two of the three anticorrosion agents, that is emulsifier (OP-10), soluble glass (Na2O·nSiO2) and glycerin (C3H8O3), were treated simultaneously on the surface of amorphous (a-) MgNi+5% Ml2Mg17 (Ml denotes the lanthanum-rich mish metal) electrode and the electrolyte. Effect of the synergistic anticorrosion treatment on charging/discharging cycle stability of the electrode was investigated. Contrasted with single treatment method, the cycling stability of the electrodes was further improved. The desirable synergistic anticorrosion method was that the electrode was treated by the soluble glass, and that OP-10 was added into the electrolyte. The cyclic voltammogram (CV) results of the electrode show clearly that the anticorrosion agent can change the electrochemical activity and mechanism of the electrode. The concentration of the anticorrosion agent in the electrolyte treated by the synergistic anticorrosion method was also investigated. The appropriate concentration of the anticorrosion agents in the electrolyte is 0.143%.