|
|
- 2015
高氯酸根阴离子在HOPG中嵌入行为的EC-STM研究
|
Abstract:
摘要 运用电化学扫描隧道显微镜（EC-STM）和循环伏安（CV）技术对高氯酸根阴离子ClO4-在高序热解石墨（HOPG）中的电化学嵌入行为进行了研究. 通过观察嵌入前后石墨台阶处高度的变化，比较了不同高度的台阶对嵌入的影响，讨论了ClO4-离子嵌入石墨的可行性、可逆性和嵌入速率. 研究表明，3层以上的台阶位才有可能观察到由四阶和三阶嵌入引起的台阶高度变化，4 ~ 8个原子层高度的石墨台阶可以实现ClO4-在台阶处较为可逆的四阶嵌入，但1 ~ 2层台阶处无法观察到嵌入引起的台阶高度变化，嵌入反应通常会伴随台阶的剥离和脱落现象. 四阶的嵌入反应较三阶可逆，二阶和一阶时，嵌入所需反应电势较高，此时氧化反应较为剧烈，嵌入反应被掩盖，很难观察到台阶高度的变化，更多的形貌变化是台面和台阶处不可逆的损坏如剥落、断层、黑坑等.
The electrochemical intercalation and surface morphology of highly oriented pyrolytic graphite (HOPG) electrode in 2 mol？L-1 HClO4 were studied by in situ scanning tunneling microscopy (STM) and cyclic voltammetry (CV). Based on the step-height changes observed before and after the intercalation, the effects of different step sites on intercalation are compared. The feasibility, reversibility and speed of intercalation are discussed. The intercalation of ClO4- into HOPG can be divided into three types depending on the number of graphite layers at the step site: When the layers of graphite are more than three, the intercalation becomes feasible; when the layers of graphite are four to eight, the intercalation can take place reversibly; However, when the graphite layers are one or two only, the intercalation cannot be observed because of the required high potential at which drastic oxidation reaction occurs concurrently. Exfoliation and etching of HOPG are the main morphological changes in this situation
| [1] | Beck F, Junge H, Krohn H. Graphite intercalation compounds as positive electrodes in galvanic cells[J]. Electrochimica Acta, 1981, 26(7): 799-809. |
| [2] | Goss C A, Brumfield J C, Irene E A, et al. Imaging the incipient electrochemical oxidation of highly oriented pyrolytic-graphite[J]. Analytical Chemistry, 1993, 65(10): 1378-1389. |
| [3] | Alliata D, H？ring P, Hass O, et al. Anion intercalation into highly oriented pyrolytic graphite studied by electrochemical atomic force microscopy[J]. Electrochemistry Communications, 1999, 1(1): 5-9. |
| [4] | Noel M, Santhanam R. Electrochemistry of graphite intercalation compounds[J]. Journal of Power Sources, 1998, 72(1): 53-65. |
| [5] | Hathcock K W, Brumfield J C, Goss C A, et al. Incipient Electrochemical oxidation of highly oriented pyrolytic graphite-correlation between surface blistering and electrolyte anion intercalation[J]. Analytical Chemistry, 1995, 67(13): 2201-2206. |
| [6] | Singh P R, Zeng X Q. Size-dependent intercalation of ions into highly oriented pyrolytic graphite in ionic liquids: An electrochemical atomic force microscopy study[J]. The Journal of Physical Chemistry C, 2011, 115(35): 17429-17439. |
| [7] | Pierson H.O. Handbook of carbon, graphite, diamond and fullerenes[M]. Park Ridge: Noyes Publications, 1993. |
| [8] | Alliata D, K？tz R, Hass O, et al. In situ AFM study of interlayer spacing during anion intercalation into HOPG in aqueous electrolyte[J]. Langmuir, 1999, 15(24): 8483-8489. |
| [9] | Aronson S, Lemont S, Weiner J. Determination of the H2SO- 4-HSO- 4 and HC1O- 4-C1O- 4 ratios in graphite lamellar compounds[J]. Inorganic Chemistry, 1971, 10(6): 1296-1298. |
| [10] | Alsmeyer D C, McCreery R L. In situ Raman monitoring of electrochemical graphite intercalation and lattice damage in mild aqueous acids[J]. Analytical Chemistry, 1992, 64(14): 1528-1533. |
| [11] | Zhang B L, Wang E K, et al. Effects of anodic oxidation on the surface structure of highly oriented pyrolytic graphite revealed by in situ electrochemical scanning tunnelling microscopy in H2SO4 solution[J]. Electrochimica Acta, 1995, 40(16): 2627-2733. |
| [12] | Wisendanger R, Guentherodt H J. Scanning tunneling microscopy I-II[M]. Berlin: Springer, 1992-1993. |
| [13] | Kinoshita K. Carbon: Electrochemical and physicochemical properties[M]. New York: Wiley, 1988. |
