Mn-Cu合金成分对去合金化法制备纳米多孔铜的影响

摘要

采用电弧熔炼制备出前驱体Mn-Cu合金,在稀盐酸溶液中自由腐蚀去合金化,制备出具有双连续结构的纳米多孔铜.研究了前驱体合金的成分对纳米多孔铜微观结构及Mn的选择性腐蚀程度的影响.结果表明:前驱体Mn-Cu合金的Cu原子分数为43%时,其去合金化受到抑制,存在明显的未完全去合金化的岛状结构;前驱体Mn-Cu合金的Cu原子分数为32%～23%时,可完全去合金化,形成平均孔径尺寸为20～100nm,平均系带尺寸为30～80 nm,具有双连续结构的纳米多孔铜;前驱体Mn-Cu合金的Cu原子分数低至20%时,去合金化后存在大量裂纹,形成纳米颗粒聚集体.纳米多孔铜中存在少量的残余Mn,残余Mn的原子分数随着前驱体合金Mn原子分数的增高而降低.实验表明腐蚀液浓度对纳米多孔铜形貌也存在影响.%Nanoporous copper with bicontinuous ligament structures can be synthesized by free corrosion dealloying in dilute HCI solution with arc melted Mn-Cu alloys. The effect of initial alloy composition on micromorphology of nanoporous Cu and residual Mn atom fraction is investigated. The results indicate that, for alloys with Cu of more than 43％ atom fraction, the dissolution of Mn is limited, leaving islands of retained Mn-Cu alloys. Bicontinuous ligament structures can be obtained as the initial Cu atom fraction decreases from 32％ down to 23％. The ligaments of size from 20 to 100 nm and the nanopore of size from 30 to 80 nm can be tailored by controlling the initial alloy composition. However, the copper ligaments become large nanoparticles as the initial Cu atom fraction is below 20 ％ and many cracks are observed after dealloying. A small amount of residual Mn exists in nanoporous copper and higher initial Mn atom fraction results in lower residual Mn atom fraction. The influence of acid concentration on the formation of nanoporosity is also investigated.