Surface Reaction Mechanism of ZVA1 Applied in Water Environment: A Review
Surface Reaction Mechanism of ZVA1 Applied in Water Environment: A Review
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ZVA1在水环境中应用的表面反应机理综述
DOI：
10.7536/pc170537
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发表时间：
2017
影响因子：
1.3
通讯作者：
Xin Jia
中科院分区：
文献类型：
--
作者：
Yang Shiying;Zhang Yixuan;Zheng Di;Xin Jia
近年来，零价铝(ZVA1)因其较强的还原能力而被用于去除水环境中的污染物，正在发展成为一种新的水处理技术。然而，ZVA1在氧气或水介质中容易氧化形成致密的氧化层，降低了ZVA1的还原能力，成为该技术进一步应用的最大限制因素。因此，全面了解ZVA1在水介质中的表面反应机理是至关重要的。事实上，由于ZVA1与水的反应可以高效地产生氢气，因此ZVA1在制氢领域已经得到了广泛的应用。从本质上讲，ZVA1对污染物的去除与Al/H2O反应制氢是相同的。在这两种情况下，ZVA1发生还原反应，并释放电子。去除污染物和产生氢气的主要区别在于，它们的电子转移目标分别是水中的污染物和水本身。为了克服表面氧化膜的局限性，这两个领域的研究人员采取了提高ZVA1还原能力的措施，包括酸或碱溶解膜，机械球磨或合金化破坏膜，建立电子通道生成有用膜，高热处理膜相变等。此外，水介质的环境条件，如温度、压力、水中的痕量离子和有机酸以及添加的氢氧化物，都对ZVA1的表面变化有显著的影响。因此，本文从氧化膜的形成、溶解、破坏、转化及其外部环境的影响等方面，对ZVA1在污染物去除和产氢方面的最新研究进展及表面反应机理进行了综述和展望。认为在克服氧化膜局限性的前提下，ZVA1将在两个领域得到广泛的应用。
In recent years, zero-valent aluminum ( ZVA1) has been used to remove contaminants in water environment due to its strong reducibility, which is developing into a new water treatment technology. However, ZVA1 can be readily oxidized to form a dense oxide layer when exposed to oxygen or water medium, which will decrease the reductive capacity of ZVA1, and become the biggest limiting factor for the further application of this technology. Therefore, it is crucial to understand the surface reaction mechanism of ZVA1 in aqueous media comprehensively. Actually, ZVA1 has been widely used in the field of hydrogen generation because the reaction between ZVA1 and H2O can generate hydrogen efficiently. In essence, the contaminants removal by ZVA1 is the same as the hydrogen generation by Al/H2O reaction. In both cases, ZVA1 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 ZVA1, 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 ZVA1. 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 ZVA1 in the fields of contaminant removal and hydrogen generation, are summarized and prospected. It is believed that ZVA1 would be applied widely in two fields supposing that the limitations of oxide film are overcomed.