摘要
近年来,具有极强还原性能的零价铝(Zero-Valent Aluminum,ZVAl)开始被应用于水中污染物的去除,正在发展成为一种新兴的水处理技术。但是,ZVAl表面被氧化形成的致密氧化层会阻碍其还原性能的发挥,成为该技术发展的限制因素。因此,全面了解ZVAl在水介质中的表面作用机制至关重要。其实,ZVAl与水反应产氢效率高,能源产氢领域的研究已相对深入。二者表面反应过程本质上相同,均是ZVAl失电子发生还原反应,最大的不同是电子的转移目标分别为水介质中的污染物和水介质本身。为克服表面氧化膜的限制,两大领域的学者们通过酸或碱溶解膜、机械球磨或合金化破坏膜、构筑电子通道形成可用膜、热处理改变氧化膜相组成等方法来处理表面膜从而提高ZVAl的反应活性。此外,ZVAl的外界水介质环境(包括温度、压力、水中存在的微量离子和有机酸、(氢)氧化物等)对ZVAl表面作用也存在显著的影响。因此,本文从氧化膜的形成、溶解、破坏、转变以及外界环境对氧化膜的影响角度出发,就目前国内外ZVAl在污染物去除和铝水反应产氢的表面作用机制方面的研究进展进行了综述和展望,以期促进ZVAl在两大领域应用的相互借鉴与共同发展。
In recent years, zero-valent aluminum （ZVAl） has been used to remove contaminants in water environment due to its strong reducibility, which is developing into a new water treatment technology. However, ZVAl can be readily oxidized to form a dense oxide layer when exposed to oxygen or water medium, which will decrease the reductive capacity of ZVAl, and become the biggest limiting factor for the further application of this technology. Therefore, it is crucial to understand the surface reaction mechanism of ZVAl in aqueous media comprehensively. Actually, ZVAl has been widely used in the field of hydrogen generation because the reaction between ZVAl and H2O can generate hydrogen efficiently. In essence, the contaminants removal by ZVAl is the same as the hydrogen generation by Al/H2O reaction. In both cases, ZVAl reduction reaction occurs, and releases electrons. The primary difference between the case of contaminant removal and the case of hydrogen generation is that their electron transfer targets are pollutants in water and the water itself, respectively. In order to overcome the limitation of surface oxide film, researchers from the two fields take measures to improve the reductive capacity of ZVAl, including film dissolution by acid or alkali, film destruction by mechanical ball milling or alloying, useful film generation by building electron channel, film phase transformation by high-heat treatment, and so on. In addition, the environment conditions of water medium, such as temperature, pressure, trace ions and organic acid in water, and （hydr）oxide added, have a significant effect on the surface change of ZVAl. Therefore, in this review, based on the oxide film＇ s formation, dissolution, destruction, transformation and the impact of its external environment, etc. , the latest research progress and the surface reaction mechanism of ZVAl in the fields of contaminant removal and hydrogen generation, are summarized and prospected. It is believed that ZVAl would be applied widely in two fields supposin
出处
《化学进展》
SCIE
CAS
CSCD
北大核心
2017年第8期879-891,共13页
Progress in Chemistry
基金
国家自然科学基金项目(No.21677135)资助~~
关键词
零价铝
氧化膜
污染物去除
铝水产氢
水介质
表面作用机制
zero valent aluminum （ZVAl）
oxide film
contaminant removal
hydrogen generation fromaluminum water reaction
aqueous medium
surface reaction mechanism
