多孔二元金属材料的制备及电化学性能研究

发布时间：2018-04-15 06:34

  本文选题：氢气泡模板法 + 湿化学法　； 参考：《东南大学》2017年硕士论文

【摘要】：多孔材料的显著优点是具有大的比表面积,可为吸附和催化提供大量位点,因而在清洁和催化等领域具有广泛的应用前景。氢气泡模板法是一种用于制备微纳米多孔金属的电化学方法,该法具有简单易行的特点。本研究以氢气泡模板法为基础制备新型微纳米多孔金属催化剂。本文首先研究了氢气泡模板法中添加剂、沉积时间和沉积电流密度对多孔铜形貌和结构的影响,通过向沉积液(0.2MCuSO4+1MH2SO4)中添加不同的离子,制备出了玉米芯状(无添加剂)、苞状(添加BTA)和雪松状(添加KCl+K2S04+NH4Cl)多孔铜簇。随着沉积时间的延长,沉积电流密度的增大,玉米芯状和雪松状三维多孔结构层数增加,韧带逐渐致密,枝晶稍有粗化,苞状铜簇苞枝晶有所增大。沉积出的多.孔铜对于偶氮染料直接蓝15具有明显的催化降解能力,且铜簇形貌、降解温度、PH值、双氧水浓度、铜簇质量和直接蓝15浓度对降解效率均有显著影响。其次,本文通过氢气泡模板法制备了微纳米多孔金簇,研究了沉积温度和沉积时间对多孔金簇形貌、结构和电化学性能的影响。随着沉积时间的延长和沉积温度的提高,样品的三维多孔结构层数增加,韧带逐渐致密,枝晶密度增大。在碱性和中性条件下,所有样品均有明显的葡萄糖催化效果,在25℃下沉积300s的样品,其催化效果最佳,碱性条件下正向扫描时的葡萄糖的氧化峰位于0.492V(vsHg/HgO)处,中性条件下正向扫描时的氧化峰位于0.405V(vs Ag/AgCl)。最后,本文结合氢气泡模板法和湿化学方法,制备了以多孔铜簇为模板的Au-Cu双金属复合材料,用于葡萄糖的催化氧化。研究了置换时间、置换反应溶剂和模板形貌对双金属催化剂的形貌、成分以及催化性能的影响。研究表明,置换后样品的多孔结构均在一定程度上发生坍塌,枝晶逐渐退化。多孔结构和枝晶结构的劣化随置换时间的延长而加深,金含量随置换时间的增加而增加。而置换后所得样品对碱性溶液中葡萄糖氧化的催化效果则在置换时间为5分钟时达到最佳。置换溶剂中乙二醇的加入可以降低置换速度,在一定程度上延缓结构劣化。纯乙二醇溶液中的置换反应则非常缓慢,金含量很低,因此在乙二醇和水的混合溶液中置换后所得的样品对葡萄糖氧化的催化效果最佳。玉米芯状、苞状和雪松状多孔铜簇置换后的样品均发生了明显的结构劣化,其中玉米芯状和苞状铜簇的劣化现象尤为显著,雪松状多孔铜簇置换后的样品对葡萄糖氧化的催化效果最佳。
[Abstract]:The advantages of porous materials are that they have a large specific surface area and can provide a large number of sites for adsorption and catalysis, so they have a wide application prospect in the fields of cleaning and catalysis.Hydrogen bubble template method is an electrochemical method for the preparation of micro-and nano-porous metals.In this study, a novel porous metal catalyst was prepared by hydrogen bubble template method.In this paper, the effects of additives, deposition time and deposition current density on the morphology and structure of porous copper in hydrogen bubble template were studied. Different ions were added to the deposit solution of 0.2MCuSO4 1MH2SO4).The corncob (without additive), bract (BTAs) and cedar (KCl K2S04 NH4Cl) clusters were prepared.With the prolongation of deposition time, the deposition current density increased, the number of corncob and cedar three-dimensional porous layers increased, the ligaments became denser, the dendrite became slightly coarse, and the bract copper cluster bract dendrite increased.There is much deposition.Pore copper has obvious catalytic degradation ability to azo dye direct blue 15, and the morphology of copper cluster, degradation temperature and PH value, hydrogen peroxide concentration, copper cluster mass and direct blue 15 concentration have significant effects on degradation efficiency.Secondly, microporous gold clusters were prepared by hydrogen bubble template method. The effects of deposition temperature and deposition time on the morphology, structure and electrochemical properties of porous gold clusters were studied.With the prolongation of deposition time and the increase of deposition temperature, the number of three-dimensional porous structure layers increased, the ligaments became denser and the dendritic density increased.Under alkaline and neutral conditions, all the samples had obvious catalytic effect on glucose. The best catalytic effect was obtained when the samples were deposited at 25 鈩，

本文编号：1752972