气泡模板法电沉积三维多孔金属膜过程调节、理论分析与构效控制

Porous metal films as electrode materials are beneficial to play sufficiently electrochemical reaction potential on electrode surface due to high specific surface area. Porous metal films can be electrodeposited by using hydrogen bubbles as template from hydrogen evolution secondary reaction during metal electrodeposition. The advantages of bubble template method are simple process and easier control for structure and properties of metal films. However, the scientific essence to electrodeposit porous films is unclear. In addition, it is difficult for iron group metals porous films to be electrodeposited by bubble template. Aiming at above bottleneck problems, the regularity that various metals are electrodeposited on different substrates is studied. Based on the enhancement of electrochemical reaction by super gravity field, the action laws of super gravity field on hydrogen bubble characteristics and electrocrystallization kinetics during metal electrodeposition are investigated in more wide range, which can not be achieved under normal condition. Furthermore, the internal relationships between formation of porous metal films and synergistic effect of bubble characteristics and electrocrystallization kinetics are elucidated. Combining with protrusion growth theory, the universal scientific essence of porous metal films electrodeposited by hydrogen bubble template is discussed. Therefore, the adjustment of structure and properties of porous films can be mastered. The results in this item will provide theoretical foundation for building universal method of electrodeposited porous functional films by hydrogen bubble template and have great scientific significance and practical value.

多孔金属薄膜拥有高的比表面积，用其作为电极材料有利于充分发挥电极的反应潜力。以金属电沉积过程析氢副反应产生的氢气泡为模板，一步电沉积多孔金属膜具有工艺简单、结构和性能易调控等优点。然而，目前气泡模板法电沉积多孔膜的科学实质尚不清楚，且该法难以适用于电沉积铁族金属（Ni、Fe等）多孔膜。本项目在考察不同类型基体与沉积金属匹配电沉积金属膜规律性的基础上，以电沉积镍基多孔膜为模型，借助超重力技术强化电化学反应的特点，在常规条件难以达到的尺度范围内，探明超重力对金属电沉积过程氢气泡析出特性和金属电结晶动力学的作用规律，解析气泡特性和电结晶动力学及其协同效应与电沉积多孔膜的内在关系，并结合突起生长理论，阐明气泡模板法电沉积金属多孔膜的共性科学实质。在此基础上，解明镍基多孔膜结构与析氢性能间的调控关系。本项目将为突破气泡模板法的局限性，建立具有普适性的制备多孔功能薄膜的通用电化学方法提供理论依据。

气泡模板法电沉积多孔金属膜具有工艺简单、薄膜结构-性能易调控等优点。本项目围绕电沉积三维多孔金属膜孔结构调节、孔形成与演变机制分析和多孔膜构效控制开展研究，认识了不同性质金属电沉积多孔薄膜动力学调节规律，明确了电沉积过程薄膜表面结构在平整-凸起-多孔膜间的演变历程，确定了多孔金属膜形成的临界条件；重点以Ni及其合金为对象，借助超重力和添加剂，实现了金属电结晶动力学和气泡析出行为的大尺度调节；建立了重力诱导对流与传质动力学间的定量关系模型，解析了超重力强化金属电沉积和对产物形貌的调节规律与机制；明确了添加剂特别是NH4Cl存在时，金属离子存在形态及其电化学极化行为对电沉积镍孔结构的作用机制；在系统研究的基础上，结合COMSOL模拟，分析了气泡吸附下，金属电沉积过程电极表面离子浓度和电流分布的动态演变过程，进而建立了多孔金属薄膜形成模型；解析了气泡模板法电沉积多孔金属薄膜的共性科学机制，掌握了气泡模板法电沉积各类型多孔金属薄膜的通用方法；以高效催化析氢为导向，超重力场强化电沉积制备了多孔NiMo膜，多孔膜厚度可达210 μm，粗糙度达19640，0.1 A cm-2电流密度下，过电位仅47 mV；通过Ag掺杂，电沉积制备了纳微多级孔结构的NiAg薄膜，具有优异的析氢活性和长期稳定性；基于几何结构和电子构型分析，解析了多孔Ni基合金析氢活性的增强机制。研究成果将为发展气泡模板法电沉积多孔功能材料的普适性方法和实现新型高性能电极材料在能源存储与转化器件中的应用，奠定理论基础和技术支撑。本项目总计发表期刊论文10篇，其中SCI论文8篇（封面论文1篇，ESI高引论文1篇）；在国内外学术会议上口头报告6次；申请发明专利2项（其中授权1项）；获得中国有色金属科技论文一等奖；负责人入选中国科学院青年创新促进会会员。