Preparation And Azo Dye Degradation Performance Of Fe-Si-B-P Nanoporous Architecture

Azo dyes which have been widely used in the printing and dyeing industry are one of the sources of water pollution.Zero-valent iron materials which are inexpensive,resourceful and non-toxic,have been extensively utilized in the degradation of azo dyes.However,rapid decay of the degradation efficiency of some of the zero-valent iron restricts the extensive utilization in degrading azo dyes.Therefore,the purpose of this project is to modify the zero valent iron material by fabricating the nanoporous structure with large surface area,which is expected to be beneficial to improving the degradation performance of azo dyes.Hence,the following work has been performed:(1)A single-roller melt-spinning method was used to produce the rapid solidification ribbons.The melt-spun specimens were nanocrystallized through annealing at 773 K-833 K.At 298 K,Fe76Si9B5P10 alloys annealed at different temperatures were dealloyed by immersing in 0.05 M H2SO4 solution for 1 h at free corrosion condition.It was found that homogeneously porous structure was formed on the specimens and the mean size of aperture increased with the increasing of the annealing temperature.(2)In order to study the effect of concentrations of solution and dealloying time on the microstructure of the nanoporous structure during dealloying,Fe76Si9B5P10 alloys annealed at 773 K were dealloyed by immersing in different concentrations of H2SO4 solution for 10-60 min at free corrosion condition.It was found that as the concentration increased,the time of obtaining the porous structure became shorter and as time went on,the number of pores increased.The microstructure of dealloyed specimens was investigated by a scanning electron microscope and the dealloying mechanism was discussed.(3)The degradation behavior of dealloyed specimens for azo dyes was studied,and Fe76Si9B10P5 amorphous powders and Fe powders were also investigated as comparisons.The results of UV-vis spectra suggested that dealloyed specimens had much better degradation efficiency for azo dyes than Fe76Si9B10P5 amorphous powders and Fe powders.(4)The degradation kinetics of degradation process were further studied and the degradation mechanism of dealloyed sample was also discussed.