An insight into the electrochemical behavior of Co/Al layered double hydroxide thin films prepared by electrodeposition

作者：Scavetta Erika^*; Ballarin Barbara; Corticelli Claudio; Gualandi Isacco; Tonelli Domenica; Prevot Vanessa; Forano Claude; Mousty Christine

来源：Journal of Power Sources, 2012, 201: 360-367.

DOI：10.1016/j.jpowsour.2011.10.122

• Co/Al layered double hydroxide
• Electrodeposition
• Coated electrode
• Electrooxidation

A detailed study aimed at clarifying the electrochemical behavior of Co/Al-LDH thin films, prepared on Pt electrode by electrodeposition at -0.9 V. has been carried out. Reproducible thin and homogeneous films with variable amounts of LDH coated on the electrode surface have been achieved by varying the electrodeposition time (t= 5, 10, 30 and 60 s): 29.2 +/- 0.7, 37.9 +/- 1.4, 55.1 +/- 2.1 and 62.5 +/- 4.3 mu g cm(-2), respectively. X-ray diffraction, spectroscopic techniques and the electrochemical quartz crystal microbalance analysis have been used to give an insight into the phase changes occurring when the as-prepared Co/Al-LDH thin films were oxidized and reduced by cycling the potential between 0 and 0.6 V/SCE in 0.1 M KOH. Our experiments demonstrate that the irreversible oxidation peak observed in the first cycle corresponds to the transformation of the Co(II)/Al-LDH phase in a gamma-Co(III)OOH like phase. This resulting phase is stable under cycling and shows a pseudo-capacitive behavior with an estimated specific capacitance of 500 F g(-1).

• 出版日期2012-3-1