Fe-Based Powders Prepared by Ball-Milling with Considerable Degradation Efficiency to Methyl Orange Compared with Fe-Based Metallic Glasses

摘要

In this study, the degradation efficiencies of zero-valent iron(ZVI) powders with different structures and components were evaluated for methyl orange(MO). The results show that the structure is an essential factor that affects degradation, and added non-metallic elements help optimize the structure. The amorphous and balled-milled crystalline Fe_(70) Si_(10) B_(20) has comparative degradation efficiencies to MO with t1/2 values of 6.9 and 7.0 min, respectively. Increasing the boron content can create a favorable structure and promote degradation. The ball-milled crystalline Fe_(70) B_(30) and Fe_(43.64 )B_(56.36) powders have relatively short t1/2 values of 5.2 and 3.3 min, respectively. The excellent properties are mainly attributed to their heterogeneous structure with boron-doped active sites in ZVI. Composition segregation in the nanoscale range in an amorphous FeSiB alloy and small boron particles in the microscale range embedded in large iron particles prepared by ballmilling, both constitute effective galvanic cells that promote iron electron loss and therefore decompose organic chemicals.These findings may provide a new, highly efficient, low-cost commercial method for azo dye wastewater treatment using ZVI.