摘要
以无水硝酸镧、1-丁基-3-甲基咪唑六氟磷酸(BMIMPF6)和助溶剂丙酮为电解液,在室温(298 K)下电沉积制得镧金属薄膜。电解液BMIMPF6的电化学窗口为-2.5~1.5 V vs. Pt,La^(3+)还原为La^(2+)发生于-1.7 V vs. Pt,La^(2+)还原为La0发生于-2.1 V vs. Pt。BMIMPF6的低吸湿性有利于在空气气氛下电沉积镧。使用扫描电子显微镜和光学显微镜观察到所制备的薄膜织构致密,经能量色散谱和X射线光电子能谱对沉积薄膜进行了表征,确定了薄膜中含有大量镧元素。通过探究电压扫描速率和硝酸镧浓度对La^(3+)的电化学行为的影响,证明La^(3+)的还原反应是一个受物质扩散控制的不可逆过程,La^(3+)在BMIMPF6中的扩散系数为1.47×10^(-9) cm^(2)·s^(-1)。本研究为获得金属镧薄膜和镧氧化物薄膜提供了一种简便的方法,并且有望用于电沉积制备其它镧系元素薄膜。
Lanthanum(La) thin film was electrodeposited at room temperature(298 K) using lanthanum nitrate, ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate(BMIMPF6) and cosolvent acetone as the electrolyte. Results show that the reduction from La^(3+) to La0 involves the transformation of La^(3+)→La^(2+) occurring at around-1.7 V vs. Pt and La^(2+)→La0 occurring at around-2.1 V vs. Pt.The electrolyte BMIMPF6 exhibits an electrochemical window from-2.5 V vs. Pt to 1.5 V vs. Pt. The low hygroscopic property of BMIMPF6 allows La electrodeposition under air atmosphere. The precipitate films were observed by scanning electron microscopy and metallographic microscope, showing a dense texture. Then the films were characterized by energy dispersive spectrometry and Xray photoelectron spectroscopy, confirming therein a large amount of La. The electrochemical tests of changing voltage scan rate and the concentration of lanthanum nitrate reveal that the reduction of La^(3+) is an irreversible process. The diffusion coefficient of La^(3+) in BMIMPF6 is calculated as 1.47×10^(-9) cm^(2)·s^(-1). This research provides a simple approach to obtain La thin film, which can be used for the electrodeposition of other lanthanides thin film.
作者
胡仪
徐劲松
钟航
张天助
陶然
潘启发
陈钧
Hu Yi;Xu Jingsong;Zhong Hang;Zhang Tianzhu;Tao Ran;Pan Qifa;Chen Jun(Science and Technology on Surface Physics and Chemistry Laboratory,Jiangyou 621908,China)
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2021年第7期2288-2292,共5页
Rare Metal Materials and Engineering
基金
National Key Research and Development Program (2017YFE0301506)
National Natural Science Foundation of China (21573223)
Foundation from Institute of Materials CAEP (TP01201603, TP03201703)。
