Hydrogen Evolution Reaction of the Electrodeposited Amorphous Ni--S—Co Alloy in Alkaline Medium

通过电沉积方法获得了Ni-S-Co非晶合金镀层．电化学测试结果表明，非晶态Ni-S-Co合金电极的析氢过电位仅为70mV，析氢反应的电化学活性高于其它种类的电极(包括非晶态Ni-S合金电极)，计算了电极的电化学参数(Tafel斜率b,交换电流密度i0和表观活化能△H^*)．XRD和SEM测试表明，在电解过程中，非晶态Ni-S-Co合金电极的电化学稳定性高于非晶态Ni-S合金电极．长时间电解实验表明，非晶态Ni-S-Co合金电极在模拟工业电解条件下具有相当高的活性和稳定性．     

镍硫钴析氢电极的制备及性能研究

采用电沉积方法制备Ni-S-Co合金电极,通过正交实验和极化曲线测试研究了CoSO4·7H2O浓度、电流密度、电镀液温度、电沉积时间和电解液温度对Ni-S-Co电极析氢性能的影响.采用SEM,XRD和EDXA对镀层的形貌、结构和组成进行观察和分析.实验结果表明:制备具有最佳析氢活性的Ni-S-Co电极的工艺条件是25 ...     

Electrocatalytic activity and electrochemical hydrogen storage of Ni-La alloy prepared by electrodeposition from aqueous electrolyte

Ni-La alloy coating was prepared by electrodeposition. The effect of cathodic current density on the La content of the alloy coatings was discussed. It is found that the content of La in the alloy increases with increasing the cathodic current density. The microstructures and codeposition mechanism of Ni-La alloy coatings were investigated by means of X-ray diffraction (XRD) and cyclic voltammetry (CV). The results demonstrate that the Ni-La alloy is FCC and codeposited by the induced mechanism. The hydrogen evolution reaction (HER) on the electrodeposited Ni-La alloy electrodes in alkaline solution was evaluated by Tafel polarization curves. It is found that La-Ni alloy coating exhibites much higher exchange current density for HER than pure Ni electrode, and that the exchange current density increases with increasing the La content of alloys. The good electrocatalytic activity for HER of this Ni-La alloy is attributed to the synergism of the electronic structure of La and Ni. The electrodeposited La-Ni alloys have a certain dectrochemical hydrogen storage capacity of 34- 143 mAh/g, which increases with increasing the La content of alloys.     

Electrocatalytic behaviour of NiBi coatings for hydrogen evolution reaction in alkaline medium

The nickel-bismuth binary coatings with various chemical compositions were galvanostatically deposited on the copper electrode in view of their possible applications as electrocatalytic materials for the hydrogen evolution reaction (HER) in alkaline solution. The HER activity of coatings was tested with the help of potentiodynamic measurements and electrochemical impedance spectroscopy (EIS) technique. The electrochemical characterization was achieved by the means of cyclic voltammetry (CV). The surface morphology and surface composition of coatings were determined with scanning electron microscopy (SEM), and energy dispersive X-ray (EDX). The potentiodynamic measurements show that, the binary coatings decrease the hydrogen over potential and increase the current density values for HER. The EIS analysis confirms, the charge transfer resistances decrease and the double layer capacitance values increase for binary coatings. The EDX results in sign that the composition of binary coating changes by using coating bath. The Cu/NiBi-2 coating (Ni²⁺/Bi³⁺ is 99.71:0.29 molar ratio) is the best suitable cathode composition for the HER in alkaline media under these experimental conditions.     

电沉积非晶/纳米晶Ni-Mo-La合金电极的析氢性能

在非晶/纳米晶Ni-Mo合金镀液中添加适量的LaCl3溶液,获得了非晶/纳米晶混合结构的Ni-Mo-La合金电极。结果表明:稀土La元素的加入,有利于镀层Mo含量的提高,形成非晶态Ni-Mo合金,细化镀层晶粒,减小镀层微应变,并使镀层表面积增加。在25℃、7 mol/L的NaOH溶液中的电化学实验表明:Ni-Mo-La合金电极比Ni-Mo合金电极具有更高的析氢催化活性,在电流密度为150 mA/cm2条件下,Ni-Mo-La合金电极的析氢过电位比Ni-Mo合金电极的降低了约80 mV。Ni-Mo-La合金具有储氢材料的特性,其析氢过程含有吸氢—储氢—脱附的过程。     

Effects of sputtering conditions on electrochemical behavior and physical properties of Ni-Mo alloy electrode

1 Introduction Many transition metal alloys with binary and ternary compositions have been studied as hydrogen evolution reaction electrodes in water electrolysis[1- 6]. The activity of such metal alloys for the hydrogen evolution reaction depends on at l…     

Ni-Cr-Cu三元合金电极制备及其析氢性能研究

以废旧紫铜片为基体,Ni粉、Cr粉为覆膜材料,通过活化反应烧结法制备了Ni-Cr-Cu三元合金电极材料。采用X射线衍射分析(XRD)、场发射电镜(SEM)、能谱(EDS)等对电极的物相、形貌结构、元素分布以及析氢产物进行表征;通过循环伏安、线性极化、交流阻抗等方法测试了合金电极材料的电催化析氢性能。结果表明,Ni-Cr-Cu三元合金薄膜电极具有优异的析氢性能,调节Cr元素的含量可提高其析氢催化活性,在室温条件下,Ni30%Cr-Cu三元合金电极材料在6 mol/L KOH的溶液中析氢性能较好,其析氢过电位仅有-0.13 V (vs RHE),交换电流密度为10 mA/cm~2时对应的极化电位为-0.145 V (vs RHE);经开路电位测试36 000 s后,电极材料的开路电位(η)从0.05 V变化为0.02 V,仅降低0.03 V,表明析氢电极化学稳定性良好。     

离子注入对钛电极析氢活性的影响

研究了离子注入工艺与注入元素对工业纯钛在硫酸和氢氧化钠溶液中析氢活性的影响,测定了工业纯钛及其注入Ni     

Electrochemical Properties of Pulse Plating Amorphous Ni-Mo-W Alloy Coating in Alkaline Medium

采用脉冲电镀技术获得了高活性Ni-Mo-W析氢合金阴极。以析氢反应过电位为考察指标,确定了脉冲镀Ni-Mo-W合金的最佳电镀条件,如Na2WO4·2H2O浓度、平均电流密度和占空比等。同时,系统研究了Mo和W含量对Ni-Mo-W合金镀层成分和组成的影响规律。结果表明,在二元合金中添加W能有效提高电极的析氢反应活性(η200＝80 mV);非晶态Ni-Mo-W合金的组织结构主要取决于Mo含量;与非晶态Ni-Mo合金镀层相比,Ni-Mo-W合金析氢阴极的电化学稳定性得到一定程度的提高。     

电沉积Ni-S合金作碱液电解活性阴极的研究进展

电沉积Ni-S合金作为碱液电解阴极材料,具有很高的析氢反应活性,能够降低析氢反应的过电位.基于文献调研并结合作者的工作,归纳了Ni-S合金的制备、晶体结构、析氢反应活性及其析氢反应机理等方面的研究状况.     

温度对La-Mg-Ni-Co-Mn贮氢电极合金电化学性能的影响

系统研究了温度对La07Mg03Ni2875Co0.525Mn0.1贮氢合金电化学性能尤其是电化学动力学性能的影响.结果表明:La07Mg03Ni2 875Co0525Mn0,合金由(La,Mg)Ni3相和LaNi5相构成.合金的最大放电容量随着温度升高从-20℃时的277.5 mAh/g增加到30℃时的406.2 mAh/g.随着温度升高,合金放电平台电位逐渐变负,放电过电位逐渐减小,合金电极的极化减弱.高倍率性能、交换电流密度、氢的扩散系数研究表明合金的电化学动力学性能随着温度升高不断提高.该合金的氢扩散活化能为17.6 KJ/mol.     

Ni-Cr-Mo-Cu多孔磷化物电极的制备及电催化析氢性能研究

为了解决电解水析氢过程中所用电极材料的低效率、高成本问题,采用粉末冶金法—低温磷化法制备了一种Ni-Cr-Mo-Cu多孔磷化物电极。采用X射线衍射分析(XRD)、场发射电镜(SEM)、X射线能谱分析(EDS)等对电极的物相、形貌结构以及元素分布等进行表征;通过开路电位、线性极化、交流阻抗等方法测试了磷化物电极材料的电催化析氢性能。结果表明Ni-Cr-Mo-,Cu多孔磷化物电极具有优异的析氢性能,调节磷化时间可在较大程度上提高其析氢催化活性。在室温条件下,磷化时间为2小时的Ni-Cr-Mo-Cu多孔磷化物电极在6mol/L KOH的溶液中析氢性能较好,其析氢过电位仅有-0.19V (vs RHE),交换电流密度为10mA/cm2时对应的极化电位为-0.20V (vs RHE);经开路电位测试18000s后,电极材料的开路电位 (η) 从+0.80变化为0.78V (vs RHE),仅降低0.02 V,表明其具有良好的电催化稳定性。     

氧化铈-镍钨复合电极的制备及其析氢催化性能

以(200)择优取向的Ni-5W合金薄带为基体,采用脱合金法制备纳米多孔NiW后,再化学溶液沉积CeO₂制备CeO₂(200)晶面暴露的NiW-nano-CeO₂复合电极。采用AFM、XRD和XPS对电极形貌和表面结构进行表征。通过阴极极化曲线和电化学阻抗技术表征各电极的电解析氢行为。结果表明,(200)晶面暴露的纳米多孔NiW-CeO₂电极比Ni(111)晶面暴露的Ni-CeO₂电极和无择优取向的NiS-CeO₂和NiZn-CeO₂电极的析氢性能好,该复合电极具有比文献中所报道的共沉积的Ni-CeO₂更高的交换电流密度1.7×10^-1 A·cm^-2。在1.0 mol/L NaOH溶液中达到电流密度100 mA·cm^-2时,过电位比NiW-CeO₂电极和NiW电极分别降低55和81 mV。选择性暴露(200)晶面的CeO     

Effect of nickel phosphide nanoparticles crystallization on hydrogen evolution reaction catalytic performance

In order to investigate the effect of nickel phosphide nanoparticles' (Ni–P NPs) crystallization on hydrogen evolution reaction (HER) catalytic performance, amorphous Ni–P NPs and crystalline Ni₁₂P₅ were synthesized by a simple and low-cost autocatalytic reduction method and heat treatment process. The result of electrochemical tests shows that crystalline Ni₁₂P₅ has much higher HER catalytic activity than the amorphous one. X-ray diffraction, transmission electron microscopy and X-ray photoelectron spectroscopy revealed that Ni–P bond formed during crystallization, making Ni positively charged and P negatively charged. This charged nature of Ni₁₂P₅ is similar to [NiFe] hydrogenase and its analogous, which make the removal of H₂ less energy-cost.     

氢传感器用铂电极的制备及性能研究

采用浆料涂覆烧结法制备铂电极,对比了基材处理方式(磁控溅射/喷砂)、铂黑(Ptb)和氧化铂(PtO₂)粒径差异对电极形貌、附着力、方阻及电催化性能的影响。结果表明,基材采用磁控溅射法制备的涂层表面结构优于喷砂法的涂层,使其剥离强度均略高于喷砂处理的样品;针对于粉末粒度,需控制在一定范围内(即Ptb(350nm)和PtO₂(350nm)),其制备的涂层表面易形成蜂窝状或絮状的微连接结构,可显著降低方阻,提高其附着力。对结构和附着力较好的Ptb/Pt电极和PtO₂/Pt电极进行CV曲线分析,PtO₂/Pt电极的电催化性能优于Ptb/Pt电极。     

Preparation of nanocrystalline palladium on p-Si by electroless deposition and its photo-electrochemical hydrogen evolution property

1. Introduction Because of the fast development of the modern industry in the last century, the reserves of fossil en-ergy resources, such as oil, natural gas, and coal, were reduced rapidly. In addition, the contamination of global environment aggravated because of the industrial growth. To overcome these problems and to find a source of renewable energy, scientists have extensively studied the utilization of hydrogen en-ergy for several decades, which is harmless to the environment [1]. Fuji…     

Electrocatalytic characterization of Ni-Fe-TiO2 overlayers for hydrogen evolution reaction in alkaline solution

The Ni-Fe-TiO₂ overlayers on mild steel strips were prepared by electrochemical deposition.The layers were characterized morphologically by confocal laser scanning microscopy and scanning electron microscopy(SEM) coupled with energy-dispersive spectroscopy(EDS)analysis.The layers exhibit a quasi-three-dimensional(3D)morphology in which the crystalline,TiO₂,is embedded.Electrocatalytic activity of the Ni-Fe-TiO₂ layers for the hydrogen evolution reaction(HER) was ...     

Electrochemical hydrogen storage properties of La0.95Mg2.05Ni9 alloy prepared by mechanical alloying

1　INTRODUCTIONTheMg basedhydrogenstoragealloysastheac tivematerialsofmetalhydrideelectrodeshaveattract edattentionbecauseofhighertheoreticalcapacitiesforhydrogenabsorption/desorption ,andthelowerpricecomparedwiththeotherhydrides[17] .Recent ly ,thecharge dischargepropertiesofMg basedalloysatroomtemperaturehavebeengreatlyimprovedbysomeresearchers[813] .Inparticular ,theMg Ni REsystemalloyisoneofthemost promisinghydrides[14 16 ] .Tanakaetal[15] reportedthatthenanocrystallineMg Ni RE(R…     

镍基非晶合金涂层的制备与腐蚀性能

用气体雾化法制备了Ni53Nb20Ti10Zr6Co6Cu3非晶合金粉末,将粒度小于25μm的非晶粉末用动力金属喷涂工艺制备了非晶涂层．研究表明,非晶涂层厚度约500μm,涂层的空隙率随喷涂温度和沉积率的增加而减少．涂层腐蚀性能的评价选用1kmol／m^3 HCl水溶液,动电位极化曲线测量表明,随着空隙率的减少,涂层呈现出与非晶合金相当的优良耐蚀性能．     

铝钙合金的制备及其水解制氢性能

通过机械球磨制备一种能快速水解制氢的Al-Ca合金。为了提高该合金的制氢效果,在机械球磨制备合金的过程中添加NaCl作为Al-Ca合金的活化改性剂,并考察NaCl添加量、机械球磨时间和Ca含量等不同因素对Al-Ca合金的制备及其制氢效果的影响。结果表明:NaCl的添加能明显抑制颗粒的团聚,提高合金的制氢产率;Al-Ca合金的制氢速率和制氢产率随合金中NaCl添加量、球磨时间和Ca含量的提高而逐渐提高。当NaCl的添加量为7%时制备得到Al-20%Ca-7%NaCl合金,将其与水反应1 200 s左右时制氢产率可达100%。