基于宏孔导电网络三维电极电催化析氢性能研究

发布时间：2018-01-07 01:16

本文关键词：基于宏孔导电网络三维电极电催化析氢性能研究　出处：《华东师范大学》2017年硕士论文　论文类型：学位论文

【摘要】：氢气作为一种可再生的清洁能源引起了人们的广泛关注。电解水制氢不会造成环境污染,也不消耗不可再生能源,是未来最具潜力且环境友好的制氢方法。本文主要利用宏孔导电网络来构建三维阵列电极,研究其应用于电解水析氢的可行性。本论文主要做了如下工作:通过标准的微机电(MEMS)加工技术制成了硅微通道板(SiMCP)结构,利用其大比表面积的特点来制备三维阵列电极,研究了一系列三维阵列电极在不同电解质中的电化学性能。首先,经过真空无电镀镍形成宏孔导电网络(MECN),而后通过水热渗碳工艺在电极表面形成碳化镍层(NiC-MCP),最后在Ar气氛中高温退火,在镍颗粒表面形成纳米石墨烯层(NG-MCP)。微结构表征和电化学测试表明,金属镍层可以改善硅微通道板导电性,提升硅材料在碱溶液中的稳定性。通过渗碳工艺获得的致密碳化镍层,可以有效保护金属镍层不被电解液腐蚀,但是过量的碳渗入使得镍层过分膨胀反而降低其稳定性。表面纳米石墨烯的形成可以有效提高表面缺陷浓度,降低宏孔导电网络的溶液接触电阻,促进快速的离子吸附/脱附反应过程。这些优异性质使得纳米石墨烯覆盖的宏孔导电网络能用于各种能源装置,如超级电容器,锂离子电池等,也可尝试将其应用于电解水析氢装置。通过电镀钯工艺对宏孔导电网络三维电极进行修饰,研究了 Pd/MECN,Pd/NiC-MCP和Pd/NG-MCP作为电极在碱性电解液中的析氢性能。电流密度10mAcm-2下,三种样品的过电位分别为96,48和47mV,而对应的塔菲尔斜率分别为185,121和112mV dec-1。在大电流密度下,Pd/NG-MCP的过电位明显小于Pd/NiC-MCP。电化学测试分析中发现,利用石墨烯高的电导率和结构稳定性的特点,通过引入纳米石墨烯层,Pd/NG-MCP三维电极具有最小的溶液界面电阻和电荷转移电阻,导电性能好,电极结构稳定,且反应速率快。
[Abstract]:Hydrogen as a clean and renewable energy has attracted widespread attention. Water electrolysis will not cause environmental pollution, but also do not consume non renewable energy, is the most promising future methods for hydrogen production and environmental friendly. The main conductive network to build three-dimensional array electrode using macro pore, study its application feasibility in alkaline water electrolysis hydrogen. The main works of this thesis are as follows: by the MEMS standard (MEMS) processing technology made of silicon microchannel plate (SiMCP) structure, with its large surface area characteristics to prepare three-dimensional electrode array, a series of three-dimensional array electrode in different electrolytes in electrochemical performance. First, after vacuum forming electroless nickel macro pore conductive network (MECN), and then through the hydrothermal carbonization process on the surface of the electrode to form nickel carbide layer (NiC-MCP), finally in Ar atmosphere high temperature annealing, formed on the surface of nickel particles Nano graphene layer (NG-MCP). The micro structure characterization and electrochemical measurements show that the nickel layer can improve the conductivity of the silicon micro channel plate, enhance the stability of silicon in alkaline solution. Through carburizing carbide dense nickel layer, can effectively protect the nickel layer by electrolyte corrosion, but excessive the nickel layer carbon into excessive expansion will reduce its stability. The formation of surface nano graphene can effectively improve the surface defect concentration, reduce the contact resistance of macro pore solution of conductive network, promote the fast ion adsorption / desorption reaction process. These excellent properties make graphene nano covering macro pore conductive network can be used for a variety of energy device, such as super capacitor, lithium ion battery, can also be applied to water electrolysis hydrogen device. Through palladium plating on macro pore conductive network three dimensional electrode modification technology, study P D/MECN, Pd/NiC-MCP and Pd/NG-MCP as the electrode for hydrogen evolution performance in alkaline electrolyte. The current density of 10mAcm-2, the overpotential of three samples were 96,48 and 47mV, and the corresponding Tafel slope are respectively 185121 and 112mV dec-1. at high current density, the over potential is significantly less than that of Pd/NiC-MCP. electrochemical studies of Pd/NG-MCP. The characteristics of the conductivity and structure stability of graphene is high, through the introduction of nano graphene layer, Pd/NG-MCP three-dimensional electrode solution interface has the least resistance and charge transfer resistance, good electrical conductivity, stable electrode structure, and the reaction rate is faster.

【学位授予单位】：华东师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TQ116.2;O646.5

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