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1.
电催化水分解是一种高效制备清洁氢气能源的有效方法. 开发高效、稳定、廉价、双功能的电催化剂用于水的氧化与还原反应一直以来都是具有挑战的课题. 在这篇论文中,作者报道了一种生长在碳布上高活性的硒化镍微球. 该催化剂通过对同时包含镍和硒元素的亚硒酸镍配合物进行电解制备. 由于前驱分子同时含有两种有效元素,制备得到的硒化镍具有很好的形貌和元素分步均一性. 制备得到的NiSe-EA/CC电极能够双功能催化水的氧化与还原. 在154 mV析氢过电势下能达到10 mA·cm-2的催化电流. 同时,在250 mV析氧过电势下能达到20 mA·cm-2电催化电流. 用该电极材料同时作为阴极和阳极制备的全电解水电解池能在1.53 V的电压下实现10 mA·cm-2的稳定电解电流.  相似文献   

2.
《电化学》2019,(5)
电催化水分解是一种高效制备清洁氢气能源的有效方法.开发高效、稳定、廉价、双功能的电催化剂用于水的氧化与还原反应一直以来都是具有挑战的课题.在这篇论文中,作者报道了一种生长在碳布上高活性的硒化镍微球.该催化剂通过对同时包含镍和硒元素的亚硒酸镍配合物进行电解制备.由于前驱分子同时含有两种有效元素,制备得到的硒化镍具有很好的形貌和元素分步均一性.制备得到的NiS e-EA/CC电极能够双功能催化水的氧化与还原.在154 mV析氢过电势下能达到10 mA·cm~(-2)的催化电流.同时,在250 mV析氧过电势下能达到20mA·cm~(-2)电催化电流.用该电极材料同时作为阴极和阳极制备的全电解水电解池能在1.53 V的电压下实现10mA·cm~(-2)的稳定电解电流.  相似文献   

3.
<正>面对目前传统化石能源的消耗及其引起的环境污染问题,新型可再生能源愈发受到关注。氢能源作为一类新型清洁能源,在解决人类面临的能源与环境问题领域中具有巨大优势。电解水作为氢气来源的有效途径,其反应进程主要受制于阳极水电解析氧反应较高的过电势。为降低反应壁垒,各类催化剂被用于析氧反应进程中。虽然  相似文献   

4.
利用氨挥发诱导法在CdSe/TiO2纳米管阵列表面负载一层NixCo3-xO4。采用SEM、XRD、XPS、UV-Vis对样品进行表征,通过线性扫描伏安法测定光阳极的释氧电势来评价其光电水氧化活性。结果表明:表面NixCo3-xO4是尖晶石结构;相对于CdSe/TiO2纳米管阵列光阳极,NixCo3-xO4/CdSe/TiO2光阳极能将光电氧化水的过电势降低430 mV。Ni离子的引入使得NixCo3-xO4表面富含三价阳离子(Ni3+,Co3+),从而促进CdSe/TiO2光阳极光电水氧化的进行。  相似文献   

5.
杨民力  张占军 《电化学》2005,11(2):133-139
应用循环伏安法和计时安培法研究了铋在玻碳电极上的电结晶行为.循环伏安曲线显示了铋在玻碳电极上成核的典型特征,并表明其于玻碳电极上的电结晶是一个扩散控制过程.根据计时安培法响应曲线分析阐明了铋的浓度和过电势对成核生长机理的影响.进一步的定量测试表明该成核速率常数A和活化点密度N0随过电势增加呈现指数增大规律;扩散系数D随过电势增加呈指数衰减.以上实验结果至今未见报道.同时表明:Scharifker公式和Heerman公式均可用于本实验的理论解释.  相似文献   

6.
采用循环伏安和电化学阻抗谱等电化学方法对金属氧化物阳极在硫酸中的寿命加速过程进行了监测.检测了阳极伏安电量,双电层电容,氧化物膜电阻和析氧反应的电荷传递电阻等电化学参数随电解时间的变化,并提出金属氧化物阳极电解失效的机理.  相似文献   

7.
当今世界环境与能源问题仍广受关注,我们所依赖的燃料电池大部分依然是不可再生的能源,如煤、石油、天然气等化石燃料,且在使用过程中产生大量的有毒有害气体,造成酸雨、温室效应等不良后果,对环境造成严重的影响.因此,寻找一种可替代化石燃料、环境友好且可再生的新能源燃料意义重大.新型高效稳定的可逆氧催化材料在可再生能源,如锌空电池的应用中具有重要作用,而这种电池是一种可再生的新型能源,对环境友好.因此,本文设计了一种具有优良的可逆氧催化性能的材料.首先通过水热法合成NiFe_2O_4前驱体,然后在管式炉中对其进行高温硫化,最后采用超声辅助液相剥离法制备了丝状界面FeS_2/NiS_2复合纳米材料.所合成的催化剂具有独特的丝状形貌和界面,因而具有优良的双功能电催化性能和可逆氧催化性能.对于氧析出反应(OER),该材料具有较低的过电势,仅需233 mV过电势即可实现析氧电流10 mA cm~(-2),该性能优于大多数报道的NiFe催化材料的性能;同时,该材料对氧还原反应(ORR)也具有很好的催化效果,其中ORR反应的起始电压为911 mV,半波电位为640 mV. OER和ORR催化活性结果表明,该材料具有优良的可逆氧催化性能,其ΔE值为0.823 V,优于贵金属催化材料.基于此,我们设计组装了液态和固态的锌空电池,并进行一系列的测试.结果表明,该系列电池在测试条件下均具有较高的开路电压和优良的充放电能力,并且在固态的锌空电池上表现出很好的可弯曲性,使其成为一种非常好的可折叠柔性固态锌空电池,具有更广泛的应用前景.这也为传统过渡金属催化材料的设计合成提供了新思路:在传统过渡金属的基础上,可通过更加新颖的合成方法使其具有独特的形貌,乃至非常好的双功能催化性和可逆氧催化性能,从而推动锌空电池的发展.另外,本文所设计的固态柔性锌空电池模型也可为相关设计应用提供参考.  相似文献   

8.
以硼氢化钠为还原剂化学镀镍的电化学研究   总被引:1,自引:0,他引:1  
采用线性电位扫描伏安法研究了以硼氢化钠为还原剂的化学镀镍体系, 考查了镀液组成及工艺条件对化学镀镍硼阴、阳极过程的影响, 结果表明: 乙酸镍和硼氢化钠含量的提高分别促进了Ni2+的还原反应和BH4-的氧化反应; 乙二胺、氢氧化钠以及添加剂硫脲、糖精钠对阴、阳极反应均有不同程度的抑制作用, 同时添加剂中的硫元素加速了镍的氧化; 升高温度有利于阴、阳极反应的进行.  相似文献   

9.
杨定乔  韩英锋 《有机化学》2006,26(12):1613-1622
综述了近年来过渡金属不对称催化氧杂苯并降冰片烯开环反应的研究进展, 包括钯催化、镍催化、铜催化和铑催化四部分内容, 并对部分反应的机理进行了介绍.  相似文献   

10.
作为未来最有潜力的制氢技术之一,电解水为解决环境污染和能源危机等问题提供了一种有效的解决途径。然而,阳极析氧反应缓慢的动力学和较高的过电位使其成为电解水装置效率提升的主要瓶颈。因此,开发高活性和高稳定性的析氧反应催化剂对于电解水技术的发展具有重要意义。近年来,镍基金属有机框架材料因其具有丰富可调的拓扑结构、较大的比表面积以及多孔特性,在催化领域受到了越来越多的关注。本文综述了镍基金属有机框架及其衍生材料在析氧催化研究中的最新进展。首先简要介绍了镍基材料在析氧反应中的原理及评价析氧催化剂活性的一些重要参数,并列举了几种镍基金属有机框架材料的结构及其在催化中的优势。随后,结合近年来发表的文献,对单金属、双金属和三金属镍基金属有机框架材料及其衍生物在析氧催化中的研究进展进行了总结与讨论,重点分析了该类材料的设计策略和催化机理。最后对该领域目前所面临的主要挑战以及未来的发展趋势进行了总结与展望。  相似文献   

11.
The effect of electrochemically ageing hydrous nickel oxide films via slow repetitive potential multi-cycling across the main nickel (II/III) redox peak was investigated in an aqueous base environment using cyclic voltammetry and steady state polarisation curves in the oxygen evolution reaction (OER) region. Similarities between hydrous nickel oxide films and electroprecipitated ‘battery type’ nickel oxide were shown due to their similar change in redox and oxygen evolving properties as a result of film ageing. This ageing method was found to significantly enhance the OER performance of the hydrous nickel oxide electrode with the OER overpotential decreasing by 60 ± 2 mV and experiencing a 10 fold increase in OER rate for a fixed overpotential over that of an un-aged electrode. The OER turnover frequency for an aged electrode was found to be 1.16 ± 0.07 s 1 in comparison to 0.05 ± 0.003 s 1 for a hydrous nickel oxide electrode not subjected to ageing.  相似文献   

12.
Nanostructured iron oxyhydroxide(Fe OOH) thin films have been synthesized using an electrodeposition method on a nickel foam(NF) substrate and effect of air annealing temperature on the catalytic performance is studied. The as-deposited and annealed thin films were characterized by X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS), field emission scanning electron microscopy(FE-SEM) and linear sweep voltammetry(LSV) to determine their structural, morphological, compositional and electrochemical properties, respectively. The as-deposited nanostructured amorphous Fe OOH thin film is converted into a polycrystalline Fe_2O_3 with hematite crystal structure at a high temperature. The Fe OOH thin film acts as an efficient electrocatalyst for the oxygen evolution reaction(OER) in an alkaline 1 M KOH electrolyte. The film annealed at 200 °C shows high catalytic activity with an onset overpotential of 240 m V with a smaller Tafel slope of 48 m V/dec. Additionally, it needs an overpotential of 290 mV to the drive the current density of 10 m A/cm~2 and shows good stability in the 1 M KOH electrolyte solution.  相似文献   

13.
We demonstrate a fit-for-purpose accelerated durability test (ADT) of a high-surface-area catalyst for the alkaline oxygen evolution reaction (OER). Using an automatized electrochemical setup enabled us to run a complex ADT protocol including online detection of the effective solution resistance as well as linear voltammetry, cyclic voltammetry, cyclic galvanograms, and electrochemical impedance spectroscopy (EIS) for 55 h in total. Using this protocol, we tested the service life stability of a nickel oxyhydroxide (NiOx) catalyst based on Raney Ni. The catalyst was prepared by growing nickel oxyhydroxide on high-surface-area Raney Ni and subsequent formation of the active phase. The successful synthesis of the active NiOx phase is supported by cyclic voltammetry and Raman spectroscopy. The as prepared and activated Raney NiOx exhibits an overpotential for the OER of 304 mV at 10 mA cm−2 with a Tafel slope of 53 mV dec−1 and roughness factors as high as 4515 determined by EIS during OER. By concentrating for the ADT protocol on current densities relevant for coupling water electrolysis to photovoltaics, it is demonstrated that Raney NiOx is a promising anode material candidate as it is earth abundant and its active phase exhibits high OER activity as well as stability.  相似文献   

14.
An iron oxide decorated nickel iron alloy nanoparticle/porous graphene hybrid exhibits high electrocatalytic activity and excellent durability toward oxygen evolution reaction (OER). It displays a low overpotential of 274 mV at 10 mA cm−2, and low Tafel slope of 37 mV dec−1, showing a superior performance to the state-of-the-art RuO2 OER electrocatalyst.  相似文献   

15.
The oxygen evolution reaction(OER) is a key step in the overall water splitting process. Numerous electrocatalysts have been developed to lower the overpotential and accelerate the kinetics of the OER. In this work, a simple soaking and heating treatment was used to form a stable and efficient Fe_xNi_(1-x)O_y/CP electrode. The electrode combined nickel and iron oxides on a commercial carbon paper were used for electrocatalytic water oxidation. The best Fe_xNi_(1-x)O_y/CP electrode(Ni/Fe = 15/1) displayed a current density of 10 mA/cm~2 at a low overpotential of 290 mV in 0.1 M KOH solution with a Tafel slope of 52 mV/dec.A higher current density of ~50 mA/cm~2 at the same overpotential and a lower Tafel slope of 43 mV/dec was obtained for this electrode in 1.0 M KOH solution. Excellent durability of the Fe_xNi_(1-x)O_y/CP electrode in 1.0 M KOH solution was confirmed under a high current density of 136 mA/cm~2 at an overpotential of 340 mV.  相似文献   

16.
曹晓燕 《电化学》1999,5(1):59-67
本文利用阴极化电沉积法在抛光镍极及ITO玻璃表面制备了含Co量为16.2%的NiOxHy薄膜,薄膜厚度分别为42nm、21nm,采用透射光谱以及线性电位扫描、交流阻抗和阳极稳态极化曲线等测试技术,考察了Co对NiOxHy薄膜电致变色性能的影响,光谱测试范围为300 ̄2500nm。结果发现:Co能降低薄膜着色态在可见光区及部分近红外区的透过率,通过电压调节不仅可以调光而且可望能够控温;同时Co还能降  相似文献   

17.
Electrochemical water splitting requires efficient, low‐cost water oxidation catalysts to accelerate the sluggish kinetics of the water oxidation reaction. A rapid photocorrosion method is now used to synthesize the homogeneous amorphous nanocages of Cu‐Ni‐Fe hydr(oxy)oxide as a highly efficient electrocatalyst for the oxygen evolution reaction (OER). The as‐fabricated product exhibits a low overpotential of 224 mV on a glassy carbon electrode at 10 mA cm?2 (even lower down to 181 mV when supported on Ni foam) with a Tafel slope of 44 mV dec?1 for OER in an alkaline solution. The obtained catalyst shows an extraordinarily large mass activity of 1464.5 A g?1 at overpotential of 300 mV, which is the highest mass activity for OER. This synthetic strategy may open a brand new pathway to prepare copper‐based ternary amorphous nanocages for greatly enhanced oxygen evolution.  相似文献   

18.
Water splitting has received more and more attention because of its huge potential to generate clean and renewable energy.The highly active and durable oxygen evolution reaction(OER)catalysts play a decisive factor in achieving efficient water splitting.The identification of authentic active origin under the service conditions can prompt a more reasonable design of catalysts together with well-confined micro-/nano-structures to boost the efficiency of water splitting.Herein,Fe,Co,and Ni ternary transition metal dichalcogenide(FCND)nanorod arrays on Ni foam are purposely designed as an active and stable low-cost OER pre-catalyst for the electrolysis of water in alkaline media.The optimized FCND catalyst demonstrated a lower overpotential than the binary and unary counterparts,and a 27-fold rise in kinetic current density at the overpotential of 300 m V compared to the nickel dichalcogenide counterpart.Raman spectra and other structural characterizations at different potentials reveal that the in-situ surface self-reconstruction from FCND to ternary transition metal oxyhydroxides(FCNOH)on catalyst surfaces initiated at about 1.5 V,which is identified as the origin of OER activity.The surface selfreconstruction towards FCNOH also enables excellent stability,without fading upon the test for 50 h.  相似文献   

19.
The nature of the oxide films formed on monel-400 and copper in presence of NaOH and N-methylpyrrolidine (a volatile amine) at pH 9.5 and in 0.1 M KNO3 medium were investigated. The oxide films were grown by applying an anodic potential of +0.4 V (vs saturated calomel electrode) for 30 min. The compositions of the surface oxide films were analysed by X-ray photoelectron spectroscopy. In the case of copper in NaOH medium, Cu(0) and a very small amount of copper hydroxide were observed. However, in amine medium, Cu(0) and Cu-amine complex were found. For monel in NaOH, the anodic film was found to contain hydroxides of both copper and nickel. After sputtering, this film showed a small amount of metal oxide below the hydroxide layer as confirmed by the oxygen peak. In amine medium the anodic film was found to contain only nickel hydroxide and metallic copper. The depth profile analysis of films showed that the film developed was very thin and the nickel hydroxide was sputtered very easily from the film. Received: 27 May 1997 / Accepted: 8 September 1997  相似文献   

20.
氢能被视为21世纪最具发展潜力的能源. 电解水制氢具有诸多优点,如原料来源广泛、操作简便、产品纯度高、无污染,已成为最具有应用前景的方法之一,但其阳极氧析出反应动力学缓慢,严重制约电解水制氢的效率. 因此,发展氧析出电催化剂尤为重要. 本文利用高温煅烧法制备了硼酸镍纳米棒,长度约为2 μm,直径约为200 nm. 与文献报道的低结晶度或无定型硼酸盐析氧催化剂不同,硼酸镍纳米棒的结晶度较高,并且具有较好的OER催化活性和稳定性. 其催化活性可以通过与其他导电材料复合或进一步减小其尺寸等方式提升.  相似文献   

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