Xie Song, Yang Yang, Gai Wei-Zhuo, Deng Zhen-Yan
Energy Materials & Physics Group, Department of Physics, Shanghai University Shanghai 200444 China
Institute of Low-Dimensional Carbon and Device Physics, Shanghai University Shanghai 200444 China.
RSC Adv. 2021 Jan 4;11(2):867-875. doi: 10.1039/d0ra09048d. eCollection 2020 Dec 24.
In this work, pristine aluminum (Al) powder was soaked in deionized water for a time period and then it was dried and heat-treated at 400 °C such that a layer of fine AlO grains covered the Al particle surfaces, forming oxide modified Al powder (OM-Al). It was found that OM-Al greatly enhanced the efficiency in removing methyl orange (M-orange) and methyl blue (M-blue) in aqueous solution. The time to completely degrade M-orange and M-blue by OM-Al is about one third of that by pristine Al powder, and decreases with increasing dosage of OM-Al. The enhancement in dye removal rate by oxide modification is much better than that with ultrasonic assistance, especially for M-blue. LC/MS spectrum analyses revealed that large dye molecules are broken into small biodegradable organic molecules after reaction with OM-Al. It is deduced that the promotion of fine AlO on the hydration process of Al surface passive oxide film is the main mechanism responsible for the enhancement of dye removal by OM-Al. Furthermore, OM-Al has a good recyclability and 80% of M-orange and M-blue can be removed even when it was reused for up to three cycles. These results indicate that oxide modification is an effective way to activate Al for the removal of organic dyes.
在本工作中，将原始铝（Al）粉浸泡在去离子水中一段时间，然后干燥并在400℃下进行热处理，使得一层细小的AlO晶粒覆盖在Al颗粒表面，形成氧化物改性Al粉（OM-Al）。研究发现，OM-Al大大提高了在水溶液中去除甲基橙（M-橙）和甲基蓝（M-蓝）的效率。OM-Al完全降解M-橙和M-蓝的时间约为原始Al粉的三分之一，且随OM-Al用量的增加而减少。通过氧化物改性提高染料去除率比超声辅助要好得多，尤其是对于M-蓝。液相色谱/质谱光谱分析表明，大的染料分子在与OM-Al反应后分解为小的可生物降解有机分子。据推断，细小的AlO对Al表面钝化氧化膜水合过程的促进作用是OM-Al提高染料去除率的主要机制。此外，OM-Al具有良好的可回收性，即使重复使用多达三个循环，仍可去除80%的M-橙和M-蓝。这些结果表明，氧化物改性是活化Al以去除有机染料的有效方法。
