Enhancing the acid orange dye degradation efficiency of Mg-based glassy alloys with introducing porous structure and zinc oxide

Mg-based alloys exhibit a good degradation performance in wastewater treatment containing dyes. The degradation performance of as-spun Mg crystalline ribbon, Mg78Zn22 (MZ) semi-amorphous ribbon and Mg73Zn22Ca5 (MZC) amorphous ribbon on acidic orange dye (AO II) solution is improved apparently by citric acid (CA) solution immersion. The degradation rate constant k of MZ ribbon after immersing for 1 h reaches 0.084 min(-1), showing a much higher degradation efficiency than other immersed ribbons. Compared with the immersed Mg and MZC ribbons, the surface of immersed MZ ribbon has a developed loofah porous structure and an appropriate crystallization. Here, the crystallization induced porous structure is composed of Zn and ZnO, which can generate more nascent hydrogen [H] by transporting Mg atoms to surface and more O-2(center dot-) radical by supplying photo-catalytic ZnO under visible light and then enhance the degradation of AO II dye. This work not only proposes a new method to improve the degradation efficiency of AO II dye by Mg-based alloys, but also provides a new insight into the microstructure and properties of Mg-based alloys. (C) 2020 Elsevier B.V. All rights reserved.