Ultrafast degradation of azo dye using surface-activated Fe-based metallic glass

This research unveils the remarkable capability of surface-activated Fe 73.5 Si 13.5 B 9 Cu 1 Nb 3 metallic glass (SA-MG) in rapidly decolorizing the acid orange II (AO II) azo dye solution. The novel chemical surface activation (CSA) process forms a heterogenous Cu-rich layer with nanoscale Cu particles on the Fe 73.5 Si 13.5 B 9 Cu 1 Nb 3 metallic glass (MG). Despite the limited number of newly formed particles and their partial coverage of the MG surface, the SA-MG can completely decolor the AO II solution in just one minute, a speed more than 25 times faster than the as-received MG. This enhanced performance is attributed to the local galvanic-cell-enhanced bimetal Fenton-like reactions and the activated surface topography. Furthermore, the activated MG surface can form caducous flakes and a sizeable new surface area that might favor surface self-cleaning and dye adsorption. The surface-activated Fe 73.5 Si 13.5 B 9 Cu 1 Nb 3 metallic glass ribbons exhibited a high degradation rate constant k (1.4∼7.4) and good reusability (13 cycles with k higher than 1.2). This discovery presents a rapid and cost-effective surface activation for Fe-based MG, offering a promising strategy for rapidly treating printing and dying wastewater.