Study On Preparation, Structure And Property Of Ni/C/Al₂O₃ Nano-electrode

Due to the unique properties of multi-porous materials, a surge of interest has been attracted since the first discovery of electrically conductive porous alumina, which can be abbreviated as CPA in this work. The CPA prepared by the combination of sol-gel and reductive sintering in argon owns high porosity, ideal conductivity and mechanical strength. All of these merits have attracted many researchers attention for its application. In this work, it is focused on researching the the surface activation of CPA and characterization and evaluation of electro-performance of as-resulted nano-composite electrode. Main work is described as follows:1. Based on the merits of CPA, acid-treatment was used for pre-treatment and an optimum condition has been pointed out in this work. By pre-treatment, various different oxygen functional groups have been grafted onto the surface of CPA without destroying alumina and nano-carbon bone structure of CPA. Because of introducing functional groups, the existence of nano-carbon networks in CPA and the widening of pores of CPA, acid-CPA displays an increased electro-chemical performance in alkaline solution.2. The effect of different reductants on surface morphology and electrochemical performance of nano-composite electrode was investigated employing acid-CPA as substrate. Compared with ethylene glycol, the Ni/C/Al₂O₃ prepared by N₂H₄ displays an enhanced propertits with smaller particles size and increased depositing amount. It is facilitated to come to a conclusion that the enhanced electrochemical performance of nanoelectrode employing N₂H₄ as reductant was attributed to the small particle size and higher depositing amount.3. The effect of depositing technology has been investigated by discussing the changes of morphology and electrochemical performance. By comparing with electroless method, chemical reduction is much more effective to prepare composite. As-resulted composite has uniformly dispersed Ni particles with 15-20 nm and without agglomeration. Furthermore, the deposited Ni nanoparticle is mainly anchored onto the surface of nano-carbon in CPA. The influence of acid-treatment and depositing time are also discussed. By investigating the electrochemical performance of composite, the enhanced performance of Ni/C/Al₂O₃ employing N₂H₄ as reductant by chemical reduction method is attributed to the nano-carbon networks and deposited Ni particles, which result in the Faradaic pseudocapacitances. The appearance of characteristic reduction peak around +210 mV and the increased reductive currents confirm the enhanced performance of resulted composite.