Rapid decoloration of azo dye Direct Blue 6 by AlCrFeMn high entropy alloy

In recent years, high entropy alloys (HEAs) have attracted a lot of attention from researchers due to their outstanding mechanical properties, but there are few reports about their functional performance. The development of new functional applications of HEAs is a challenging, but very meaningful topic. The decoloration of azo dye Direct Blue 6 (DB6) using equiatomic AlCrFeMn HEA synthesized by ball-milling is reported in this study. Ball-milled (BM) AlCrFeMn HEA shows excellent performance in the decoloration of DB6, 3 times faster than BM MgZn-based glassy powders and AlCoCrTiZn HEA, which are reported as the best among the metallic glasses and HEAs so far, respectively. The effects of initial pH, initial temperature and dye concentrations on the decoloration efficiency during reaction are systematically studied. This work can greatly expand the applications of HEAs, especially the application of their functional properties.