Fast decolorization of azo dyes in both alkaline and acidic solutions by Al-based metallic glasses

The advanced efficiency of metallic glasses in degrading organic water pollutants has attracted wide interests. Yet the decolorization efficiency decreases in alkaline solutions which remains a challenge for their application. In this work, the performance of Al-91_xNi9Yx (x = 0, 3, 6, 9 at.%) metallic ribbons in degrading azo dye in aqueous solutions at wide pH conditions is studied. It is surprising to find that the reaction activity of Al-based metallic glass in alkaline and acidic azo dye solution is about 1.5 and 189 times higher than that in neutral solutions, respectively. The low reaction activation energy and formation of nano-porosity on the surface of metallic glass are responsible for the high reactivity in alkaline and acidic solutions. The reaction activity can be further enhanced by modifying the alloy composition. These findings suggest that the A-based metallic glasses hold promising potential in degrading azo dyes solutions, especially in alkaline and acidic environments. (C) 2017 Elsevier B.V. All rights reserved.