钛基体中离子注入镍和钼的电催化活性

Grenness等发现,铂离子注入钨基体中,对H~+还原产生的电催化性能与纯铂相近,此后,Wolf等用离子注入和离子束混合技术制作了多种电极,其中Pt/RuO_2、Pt/C、Pt/WC电极用于H~+和O_2的电还原以及甲醇和甲酸的电氧化,其催化活性和稳定性均优于光滑的纯铂电极,目前,在其它方法制作的析氢电极材料中,最可能用于工业电解槽的为NiMo合金电极和复合Raney镍合金电极,本工作将镍和钼离子注入到钛基体中,研究了此电极在30 wt％KOH溶液中析氢电催化行为,并通过电子探针显微分析(EPMA)和X射线光电子能谱(XPS)分析,检测了离子注入电极的表面成分、注入元素的浓度分布及价态。     

电沉积镍钨注钼电极的析氢反应

在所有电极过程中研究最多的是析氢反应,其重要性一直为化学界所关注。提高电极活性的各种方法中,普遍采用电沉积法,它价廉简便、效果明显。但涂层不够牢固,在使用过程中易脱落,使用寿命短。为了克服上述缺点,作者将电沉积和离子注入技术联合使用,即在Ni、W镀层上注入Mo离子,利用Mo离子的能量将Ni、W打入表面内层,进行离子束混合。这既     

含稀土的镍基合金的析氢电催化行为

用电沉积方法制备的Ni-Ce-P和Ni-La-P合金作阴极测得析氢阴极极化曲线,结果表明,合金电极上析氢速率比Ni电极上约大10倍,析氢电热政移＞200mV,显示出含稀土的镍基合金具有较高的析氢催化活性,根据XPS谱图讨论了析氢的电催化机制。     

氧化铁镍电极上析氧反应的电化学研究

应用射频反应磁控溅射法制备阳极催化氧化铁镍薄膜,由循环伏安、线性扫描伏安、极化曲线和电化学交流阻抗谱等研究发生在该电极上的氧化反应.结果表明,作为活化中心的铁能使过电势降低,并且随着溅射过程氧流量的增加催化性能增强,铁的掺入使得速率限定步骤由OH-的释放变为氧原子的结合.与镍相比,氧化铁镍是更理想的催化阳极材料,当电流密度为50 mA/cm2时,其氧的过电势比镍的下降了500 mV.     

钛、玻璃碳基体中离子注人镍的电化学性能

钛、玻璃碳基体中离子注入5×10~(16)×10~(1(?)Ni~+离子cm~(-2).在30%KOH溶液中测试这些电极对氢析出反应的电催化性能.结果表明,离子注入电极的催化活性优于未注入的钛、玻璃碳基体.由极化测量求得动力学参数j、b和E.这些数据表明,在离子注入电极上,氢析出反应的速度决定步骤与镍电极相似,由电化学放电步骤控制。AES测量表明,镍在钛基体中的深度分布近似高斯分布,在阴极极化过程中,注入的镍没有损失,但明显地移向深处.用XPS研究注入前后Ni_(2p)和Ti_(2(?))电子结合能所产生的位移表明,离子注入可能在基体表面形成合金.     

W离子注入Ni-Mo合金电极的析氢性能

本文在镍基上电沉积Ni-Mo合金层,用W^+束注入,得到活性和稳定性极佳的新型析氢电极。     

镍钒合金电沉积及其析氢电催化性能的研究

镍钒合金电沉积及其析氢电催化性能的研究林文修王树喜（福建师范大学化学系福州３５０００７）关键词镍钒合金电镀电催化析氢反应对电化学的能量转换、电合成、金属沉积和防腐等具有重要意义，选择和探索优良的过渡金属电催化剂是研究析氢电催化阴极的主要方向。１９７８...     

钛基二氧化铅电催化电极的制备及电催化性能研究

以电沉积法制备了钛基PbO2电极，优化并确定了电极的制备工艺，以苯酚为目标有机物，考察了电极的电催化氧化性能，研究结果表明，该电极的电催化性能优于传统的DSA钛基RuO2电极。采用该电极，在10Ma/cm^2电流密度下通过0.72Ah电量后，可使100Ml、COD浓度为270mg/L的苯酚溶液中的苯酚完全分解，COD去除率为67.4%，单位电量COD降解量为0.254mgCOD/Ah，且电流效率随电流密度的增加而减小，初步研究了苯酚的电催化氧化机理，提出了苯酚的电催化氧化可能是由苯酚的直接电化学氧化为苯醌及苯醌的间接电化学氧化有机酸两部分组成。     

碱性介质中高择优取向（220）镍电极上丙醇的电氧化

对１．０ｍｏｌ／ＬＮｉＳＯ４和０．５ｍｏｌ／Ｌ Ｈ３ＢＯ３体系，控制电位为一１．２５Ｖ，沉积６０ｍｉｎ，制得高择优取向镍电极。该镍电极经Ｘ射线衍射测定其织构度ＴＣ２２０为９２％。采用循环伏安法研究了１ｍｏｌ／Ｌ ＮａＯＨ溶液中高择翁取向镍电极上丙醇的电催化氧化机理有活性，结果表明：高择优取向镍电极对正丙醇的电催化活性高，对异丙醇的电催化活性小；推导出正丙醇的电氧化动力学方程，运用稳态极经曲线测定了     

Hydrogen Evolution Reaction on Thermodiffusion Treated Nickel-Implanted Titanium Electrodes

Implating ions with high-energy into the surface of electrode can introduce catalytically active elements, and thus form a large number of active centers to improve the catalytical activity. As a result of implanting nickel ions into Ti-electrode we get a overpotential decrease of hydrogen evolution by 245 mV and the electrode was much more active than the unimplanted one. The experiment shows that the catalytical activity of the electrodes raises with the increase of the surface nickel ions concentration. The maximum concentration of ions were not on the electrode surface, as the deep distribution of the     

Studies on Ion-Beam Modified Hydrogen Evolution Electrodes

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Studies on Structure and Electrocatalytic Hydrogen Evolution of Nanocrystalline Ni-Mo-Fe Alloy Electrodeposit

NanocrystallineNi Mo Fealloydepositswereobtainedbyelectrode position .ThestructuresofthealloydepositswereanalyzedbyX raydiffraction (XRD )andX rayphotoelectronspectroscopy(XPS) .TheXRDresultsofnanocrystallineNi Mo Fealloydepositshowthatmanydiffractionlinesdisappear ,andthatthereisonlyonediffractionpeakat 44 .0° .TheXPSresultsofnanocrystallineNi Mo Fealloydepositsindicatethatthenickel,molybdenumandironofthedepositsexistinmetallicstate ,andthatthebindingen ergyofthealloyedelementsincre…     

Intensifying Hydrogen Spillover for Boosting Electrocatalytic Hydrogen Evolution Reaction

Hydrogen spillover has attracted increasing interests in the field of electrocatalytic hydrogen evolution reaction (HER) in recent years because of their distinct reaction mechanism and beneficial terms for simultaneously weakening the strong hydrogen adsorption on metal and strengthening the weak hydrogen adsorption on support. By taking advantageous merits of efficient hydrogen transfer, hydrogen spillover-based binary catalysts have been widely investigated, which paves a new way for boosting the development of hydrogen production by water electrolysis. In this paper, we summarize the recent progress of this interesting field by focusing on the advanced strategies for intensifying the hydrogen spillover towards HER. In addition, the challenging issues and some perspective insights in the future development of hydrogen spillover-based electrocatalysts are also systematically discussed.     

Nicotinamide Adenine Dinucleotide Oxidation Studies at Multiwalled Carbon Nanotube/Polymer Composite Modified Glassy Carbon Electrodes

NADH oxidation has previously been investigated at carbon nanotube surfaces, although studies into the effect of the polymer binders are needed to fully understand whether the polymer binder affects the electrochemistry. This work details NADH oxidation at glassy carbon electrodes modified with composites containing multiwalled carbon nanotubes and selected polymer binders. NADH is shown to be oxidized at a lower potential than at glassy carbon electrodes and the oxidation potential is a function of the polymer binder. Hydrophobically modified Nafion, Nafion, linear poly(ethylenimine) (LPEI), octyl‐modified LPEI, and poly(vinylpyridine) binders were studied. Experiments showed the peak current and electrochemically assessible electrode area are dependent on the polymer binder. Overall, this paper shows that polymer binders affect NADH oxidation potential at carbon nanotube modified electrodes.     

对甲基苯酚在不同催化剂电极上的电氧化

在无隔膜电解槽中, 利用线性伏安法和恒电流电解法研究了Ti/PbO2、石墨和Pt电极对于对甲基苯酚电氧化的催化活性, 通过电解前后溶液中对甲基苯酚及其氧化中间产物的液相色谱测定, 比较了对甲基苯酚在3种电极上的转化和降解速度, 并讨论了对甲基苯酚电氧化降解的历程和速控步骤. 研究结果表明, Ti/PbO2电极能有效地催化氧化水溶液中的对甲基苯酚, 并将其彻底去除, 电极活性较高; 石墨电极也能够催化氧化水溶液中的对甲基苯酚, 但效果较差; Pt电极在3.0 h的电解时间内, 只能将对甲基苯酚转化成对苯二酚, 而不能将其完全矿化. 对甲基苯酚电氧化降解需要经过对羟基苯甲醇→对羟基苯甲醛→对羟基苯甲酸→对苯二酚→对苯醌→顺丁烯二酸→草酸, 最终生成二氧化碳和水的历程. 当以Ti/PbO2作阳极时, 对苯二酚转化为对苯醌和顺丁烯二酸转化为草酸两步反应为较慢的速控步骤; 当以石墨作为阳极时, 对苯二酚转化为对苯醌的反应为速控步骤.     

Catalysis of Hydrogen Evolution by Polylysine,Polyarginine and Polyhistidine at Mercury Electrodes

Protein catalyzed hydrogen evolution reaction at mercury‐containing electrodes controlled by constant‐current chronopotentiometric stripping (CPS) is representing a new tool useful in protein research. The resulting CPS peak H is sensitive to changes in the protein structure and its amino acid composition. Besides CPS, cyclic voltammetry appears to be useful for study of poly(amino acids) as an intermediate model system between peptides and macromolecular proteins. Here we show that similarly as arginine in polyarginine and lysine in polylysine also histidine residues in polyhistidine contribute to the catalysis of hydrogen evolution under the given conditions. Peak potentials of individual poly(amino acids) are different and depend on the type of amino acid residues.     

Controlled Carbon Nitride Growth on Surfaces for Hydrogen Evolution Electrodes

Efficient and low‐cost electrocatalysts for the hydrogen evolution reaction are highly desired for future renewable energy systems. Described herein is the reduction of water to hydrogen using a metal‐free carbon nitride electrocatalyst which operates in neutral and alkaline environments. An efficient, easy, and general method for growing ordered carbon nitride on different electrodes was developed. The metal‐free catalyst demonstrates low overpotential values, which are comparable to those of non‐noble metals, with reasonable current densities. The facile deposition method enables the fabrication of many electronic and photoelectronic devices based on carbon nitride for renewable energy applications.     

在纳米晶Co－Mo／Ni复合电极上的析氢反应

采用复合电镀的方法将不同球磨时间制备的高催化活性的纳米晶Ｃｏ－Ｍｏ合金粉直接镀在电极表面,用稳态极化曲线及交流阻抗技术测试了这些电极析氢的电化学活性,并用Ｘ射线衍射、透射电镜及Ｘ射线光电子能谱、扫描电镜监测了Ｃｏ－ＭＯ合金粉的物相结构、晶粒尺寸和复合镀层的成份、形貌,实验结果表明,Ｃｏ－Ｍｏ纳米晶合金粉有较高的析氢催化活性。球磨使钴钼粉合金化成为纳米晶,一方面增加了复合镀层的真实表面积,另一方面由于纳米晶合金具有高比例的表面活性原子,致使析氢活化能降低,加快了析氢反应,研究表明在不太高温度下,电化学脱附的活化能和整个析氢反应的活化能一致。说明电化学脱附为速度控制步骤。