利用表面配位層鈍化銅的氧化反應，這一成果由廈門大學Nanfeng Zheng、Lan-Sun Zheng和北京大學Ying Jiang研究小組合作取得。 這一研究成果于2020年10月14日發表在國際頂尖學術期刊《自然》上。
課題組曾經報道使用溶劑熱合成法，以甲酸為還原劑制備高空氣穩定的銅納米片。研究人員報告，在甲酸鈉的存在下，溶劑熱法處理銅會導致銅表面的晶體學重建和一個超薄表面配位層的形成。小組揭示表面改性不影響銅的熱/電導率，但引入了在空氣、鹽霧以及堿性條件的抗氧化性能。研究人員也開發一種快速室溫電化學合成方法，由此產生的材料證明同樣強大的鈍化性能。
研究組通過引入烷硫醇配體與未被鈍化層保護的缺陷位點進行配位，進一步提高銅表面的抗氧化性。研究組證明，溫和的處理條件使這項技術適用于制備各種形式的空氣穩定的銅材料，包括箔，納米線，納米顆粒和塊狀漿料。該研究組預期這項工作中所開發的技術將有助于擴大銅的工業應用。
據了解，由于銅具有高熱/電導率、好的延展性和整體無毒性的特點，被廣泛用于日常應用和工業中，尤其在抗氧化技術方面。然而，許多廣泛使用的抗氧化技術，例如合金和電鍍，通常會影響一些物理特性(例如熱/電導率和顏色）和引入有害元素，如鉻和鎳。盡管已努力開發以有機分子，無機材料或碳基材料為抗氧化劑的表面鈍化技術，其大規模使用仍未成功。
附：英文原文
Title: Surface coordination layer passivates oxidation of copper
Author: Jian Peng, Bili Chen, Zhichang Wang, Jing Guo, Binghui Wu, Shuqiang Hao, Qinghua Zhang, Lin Gu, Qin Zhou, Zhi Liu, Shuqin Hong, Sifan You, Ang Fu, Zaifa Shi, Hao Xie, Duanyun Cao, Chang-Jian Lin, Gang Fu, Lan-Sun Zheng, Ying Jiang, Nanfeng Zheng
Issue&Volume: 2020-10-14
Abstract: Owing to its high thermal and electrical conductivities, its ductility and its overall non-toxicity, copper is widely used in daily applications and in industry, particularly in anti-oxidation technologies. However, many widespread anti-oxidation techniques, such as alloying and electroplating, often degrade some physical properties (for example, thermal and electrical conductivities and colour) and introduce harmful elements such as chromium and nickel. Although efforts have been made to develop surface passivation technologies using organic molecules, inorganic materials or carbon-based materials as oxidation inhibitors, their large-scale application has had limited success. We have previously reported the solvothermal synthesis of highly air-stable copper nanosheets using formate as a reducing agent. Here we report that a solvothermal treatment of copper in the presence of sodium formate leads to crystallographic reconstruction of the copper surface and formation of an ultrathin surface coordination layer. We reveal that the surface modification does not affect the electrical or thermal conductivities of the bulk copper, but introduces high oxidation resistance in air, salt spray and alkaline conditions. We also develop a rapid room-temperature electrochemical synthesis protocol, with the resulting materials demonstrating similarly strong passivation performance. We further improve the oxidation resistance of the copper surfaces by introducing alkanethiol ligands to coordinate with steps or defect sites that are not protected by the passivation layer. We demonstrate that the mild treatment conditions make this technology applicable to the preparation of air-stable copper materials in different forms, including foils, nanowires, nanoparticles and bulk pastes. We expect that the technology developed in this work will help to expand the industrial applications of copper.
DOI: 10.1038/s41586-020-2783-x
Source: https://www.nature.com/articles/s41586-020-2783-x