纳米多孔铜制备及其电化学性能研究

Preparation of Nanoporous Coppers and Their Electrochemical Properties

通过真空熔炼和快速凝固技术制备了Cu-55Al(at%)合金铸锭和快淬薄带,用稀盐酸浸泡法对所得合金进行了化学脱合金。采用XRD、SEM和TEM等方法对脱合金前后的相组成及微观形貌进行了表征。结果表明,合金原始物相均由AlCu和Al2Cu相组成,快淬薄带中Al2Cu相含量更高。二者经脱合金后均能获得三维无序网状多孔铜,孔带平均尺寸分别为83、58 nm。此外,块体多孔铜中虽有少量Al残余,但孔带光滑完整。而合金薄带虽然能够完全脱Al,但孔带表面粗糙,并含有少量的Cu2O。电化学测试表明,多孔铜在碱性条件下电氧化甲醇的电流密度较光滑铜电极提高了25倍,同时还表现出优良的电容性能。

Cu-55Al （at%） alloy ingots and ribbons were prepared by vacuum melting and rapid solidification and then the chemical dealloyingwere carried out by immersing in dilute hydrochloric acid solution. The phase composition and the morphology of the Cu-AI alloy ingots, ribbonsand nanoporous coppers （NPCs） were characterized by XRD, SEM, TEM and so on. The results show that both of Cu-Al alloy ingots and ribbonscontain AICu and Al2Cu phase, while there is higher content of Al2Cu phase in ribbons. The nanoporous copper （NPC） blocks and ribbons can befabricated through chemical dealloying of Cu-Al alloy ingots and ribbons, respectively. The NPCs exhibit a three-dimensional and disorderednetwork-like ligament structure. The mean ligament sizes of NPC blocks and ribbons are 83 nm and 58 nm, respectively. After dealloying, a smallamount of Al is still in alloy ingots, but the NPC blocks ligament are smooth and complete. However, A1 can be completely removed in alloyribbons with smaller diameter, rough surface, and trace Cu2O. Electrochemical performance of NPC blocks was analyzed by cyclic voltammetry（CV） curves and electrochemical impedance spectroscopy. Electrochemical tests show that current density has been increased by 25 times ascompared with the smooth copper electrode in a mixture of methanol and alkaline solution. Meanwhile, NPC blocks have good capacitancecharacteristics.