金属氢氧化物的电沉积制备及电极性能研究

3d-electron transition metal hydroxides are promising cheap and abundant electrode materials for water electrolysis and supercapacitors. In this program, we will study the general electrodeposition synthesis of 3d metal (e.g., Fe, Co, Ni) hydroxides and their composite materials. We plan to investigate the co-electrodeposition behaviors of different metals and reveal the nucleation and growth of hydroxides. The interaction and compatibility between electrodeposit and substrate will be studied thoroughly to develop efficient strategies for enhancing the interfaces. We attempt to build self-supporting metal hydroxides and their composite electrodes with high mechanical strength and structure stability. Electrode properties of the synthesized metal hydroxides will be investigated in electrochemical energy storage and conversion technologies such as water electrolysis and supercapacitors. We aim to address the issues associated with the electrodeposition of electrode materials, including poor universality, difficult interface engineering, low mass loading and limited application at high currents. The completion of this program would enlighten the theoretical and experimental design and preparation of high-performing metal hydroxide electrode materials.

3d过渡金属氢氧化物是一类低成本、来源丰富的电极材料，可应用于电解水析氧与超级电容器。本项目拟研究Fe、Co、Ni等氢氧化物及其复合材料的通用电沉积制备方法，研究异金属氢氧化物电化学共沉积规律、成核与生长机理，研究电沉积产物与基底的界面相容性，发展沉积物与基底之间结合力增强策略，构筑高机械强度和结构稳定性的自支撑金属氢氧化物及其复合电极，探索它们在电解水、超级电容器等电化学能量储存与转化体系中的应用性能，解决电沉积制备存在的材料通用性差、界面调控困难、沉积载量低、大电流应用受限等问题，为高性能金属氢氧化物电极材料的设计制备提供理论指导与实验依据。

本项目围绕3d过渡金属氧化物/氢氧化物、硫化物及复合电极材料的电沉积制备及其电催化应用展开研究。发展了含氧酸离子嵌入辅助的阴极电沉积方法，获得超细Pt修饰氢氧化物的Pt/NiCeOxHy，展现出优异的双功能催化活性，100mA/cm2电流密度下析氢过电位76mV，析氧过电位186mV。将电沉积金属氢氧化物与后续高温选择性还原结合，制备了石墨基底负载的NiCo-CeO2催化剂，通过纳米合金与氧化物的界面耦合优化电子结构和氢吸脱附能，降低了析氢过电位。通过电沉积顺序调控，制备系列金属硫化物/氢氧化物双层自支撑电极，揭示了Ni3S2-Fe(OH)2电极外层致密单晶Ni3S2阻断铁溶出，促进电化学重构形成活性相NiFeOxHySz，在1A/cm2大电流密度下可稳定工作300h。发展了电电化学还原-刻蚀法调控FeNi2O4尖晶石中阳离子缺陷，揭示了Fe缺陷对析氧活性的显著增强作用。研究结果为电沉积制备自支撑结构金属氢氧化物电极、优化界面性质、提升电催化性能提供了实验依据。