Amorphous-nanocrystalline dual-phase structured Fe78Si13B9 alloy ribbons and their efficiency for degradation of direct yellow dye

In this study, the amorphous-nanocrystalline dual-phase structure Fe78Si13B9 alloy ribbons (FeSiB) were prepared by single roll stripping method. The degradation efficiency of FeSiB for direct yellow dyes (DYGR) was 83% at a water bath temperature of 35 C-degrees, pH = 7, and without any oxidizer addition. The characterization results show that the galvanic cell structure is formed between the nanocrystals and amorphous matrix, which makes it easier for Fe-0 to lose electrons and accelerate electron transfer, thus promoting the degradation reaction. Ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS) was employed to identify the intermediates. The specific degradation pathway of DYGR by FeSiB ribbons is proposed for the first time based on these 18 intermediates. The mechanism studies show that [H] produced by FeSiB plays a special role in the degradation pathway of DYGR, and is more likely to react with electron-withdrawing group. This work provides a new idea for understanding the degradation mechanism of azo dyes by Fe-based alloys.