磷化物修饰碳纳米管海绵的制备及电解水制氢性能研究

发布时间：2018-01-19 02:18

本文关键词： 碳纳米管海绵磷化镍磷化钴镍电解水制氢　出处：《郑州大学》2017年硕士论文　论文类型：学位论文

【摘要】：随着能源消耗和环境污染的加剧,发掘利用可再生的清洁能源引起了人们的广泛关注。电解水制氢产业得到了迅速的发展,电解水制氢可有效将富余的电能转化为氢能存储起来。三维多孔的碳纳米管海绵具有优异的电学、力学等性能,将其作为电催剂的基底,可有效提高复合催化剂中的电子传导速率,优化催化剂的纳米结构,增加催化剂的比表面积。有望提高电催化制氢中电能转化为氢能的效率。本论文以提高催化剂的性能为目标,采用电沉积法在碳纳米管海绵上直接生长过渡金属磷化物,探索了电沉积参数与催化剂的形貌、性能之间的关系,研究了不同pH值的电解液对碳纳米管海绵复合电极电解水制氢和制氧性能的影响。采用化学气相沉积法制备碳纳米管海绵,将亲水处理后的碳纳米管海绵制备成电极。之后,采用循环伏安法制备磷化镍纳米颗粒/碳纳米管海绵复合电极,通过调控电沉积过程中的循环次数,调控催化剂的形貌和尺寸,优化催化剂的性能。电沉积过程中磷化镍纳米颗粒直接在碳纳米管表面形核长大,保证了磷化镍和碳纳米管之间的良好接触,实现电子快速传导。磷化镍/碳纳米管复合电极在酸性、中性和碱性电解液中表现出优异的电解水制氢性能,在中性电解液中产生10 mA cm-2的电流密度仅需105 mV的过电势,恒电压测试110 h后催化活性无明显变化,稳定性较好。通过电沉积法将三元电催化剂磷化钴镍负载到碳纳米管海绵上,得到磷化钴镍/碳纳米管海绵复合电极,调控电解液中钴和镍的前躯体比例与浓度,调整磷化钴镍中钴和镍的比例与形貌。其在中性电解液中产生10 mA cm-2电流密度的过电势为93 mV,在碱性环境中表现出优异的电解水制氢和制氧双功能性,产生10 mA cm-2电流密度的过电势分别为73 mV(制氢)与288 mV(制氧)。
[Abstract]:With the intensification of energy consumption and environmental pollution, the exploitation and utilization of renewable clean energy has aroused widespread concern. The hydrogen production industry of electrolytic water has been developed rapidly. Electrolysis of water to produce hydrogen can effectively convert surplus electric energy into hydrogen energy storage. Three-dimensional porous carbon nanotube sponge has excellent electrical and mechanical properties, which is used as the substrate of electrocatalyst. It can effectively improve the electron conduction rate in the composite catalyst and optimize the nanostructure of the catalyst. Increasing the specific surface area of the catalyst is expected to improve the efficiency of conversion of electric energy to hydrogen energy in electrocatalytic hydrogen production. This paper aims to improve the performance of the catalyst. Transition metal phosphates were grown directly on carbon nanotube sponges by electrodeposition, and the relationship between electrodeposition parameters and the morphology and properties of the catalysts was explored. The effects of different pH values on the hydrogen and oxygen production properties of carbon nanotube sponge composite electrode were studied. Carbon nanotube sponge was prepared by chemical vapor deposition. The hydrophilic carbon nanotube sponge was prepared into an electrode, and then the nickel phosphide nanoparticles / carbon nanotube sponge composite electrode was prepared by cyclic voltammetry. During electrodeposition, nickel phosphide nanoparticles grew directly on the surface of carbon nanotubes, which ensured good contact between nickel phosphide and carbon nanotubes. The nickel phosphide / carbon nanotube composite electrode exhibited excellent hydrogen production performance in acidic neutral and alkaline electrolytes. The current density of 10mA cm-2 produced in neutral electrolyte requires only 105mV overpotential, and the catalytic activity does not change obviously after constant voltage test for 110h. The composite electrode of cobalt and nickel phosphide / carbon nanotube sponge was obtained by electrodeposition of cobalt and nickel phosphide onto carbon nanotube sponge. The ratio and concentration of cobalt and nickel in electrolyte were regulated. The overpotential of 10 Ma cm-2 current density produced in neutral electrolyte was 93 MV by adjusting the ratio and morphology of cobalt and nickel in cobalt and nickel phosphide. In alkaline environment, the double functions of hydrogen production and oxygen production by electrolytic water are excellent. The overpotential of 10 Ma cm-2 current density is 73 MV (hydrogen production) and 288 MV (oxygen production), respectively.
【学位授予单位】：郑州大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O643.36;TQ116.2

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