Effects of structural relaxation on the dye degradation ability of FePC amorphous alloys

The effects of structural relaxation on the catalytic efficiency of FePC amorphous ribbons in the Fenton-like reactions are studied. Different from previous knowledge, the catalytic efficiency of the Fe-based amorphous ribbons doesn't decrease linearly with increased annealing temperature before glass transition. The catalytic ability of the FePC ribbons annealed at 553 and 593 K is worse than that of as-quenched ribbons, while the ribbons treated isothermally at 633 and 673 K show higher catalytic efficiency. The impacts of structural relaxation on dye degradation performance should be considered from two aspects: i) The stored energy in the metastable ribbons, which comes from the high enthalpy and residue stress, decreases with increased annealing temperature, leading to the depression of degradation performance. ii) The precipitation of nanocrystals in the amorphous matrix when annealed at temperatures close to glass transition promotes the formation of galvanic cells that improve the catalytic efficiency of the ribbons.