Enhanced Azo-Dyes Degradation Performance of Fe-Si-B-P Nanoporous Architecture

Nanoporous structures were fabricated from Fe(76)Si(9)B(10)P(5) amorphous alloy annealed at 773 K by dealloying in 0.05 M H(2)SO(4) solution, as a result of preferential dissolution of α-Fe grains in form of the micro-coupling cells between α-Fe and cathodic residual phases. Nanoporous Fe-Si-B-P powders exhibit much better degradation performance to methyl orange and direct blue azo dyes compared with gas-atomized Fe(76)Si(9)B(10)P(5) amorphous powders and commercial Fe powders. The degradation reaction rate constants of nanoporous powders are almost one order higher than those of the amorphous counterpart powders and Fe powders, accompanying with lower activation energies of 19.5 and 26.8 kJ mol(−1) for the degradation reactions of methyl orange and direct blue azo dyes, respectively. The large surface area of the nanoporous structure, and the existence of metalloids as well as residual amorphous phase with high catalytic activity are responsible for the enhanced azo-dyes degradation performance of the nanoporous Fe-Si-B-P powders.