Role of carbon materials on the aging-resistance of zero-valent aluminum for pollutant removal.

In recent years, zero-valent aluminum (ZVAl) has attracted significant attention as a novel material in the field of water treatment. However, its high reactivity leads to rapid aging when exposed to air, limiting its preservation and practical utilization. To address this issue, carbon materials modified ZVAl (C@ZVAl) were prepared by mechanical ball-milling to improve the aging resistance of ZVAl. These carbon materials used as a grinding aid included activated carbon (AC), biochar (EBC), graphene (GE), hydrophobic graphite (Gr) and carbon nanotubes (CNTs). It was investigated how carbon materials affected ZVAl's aging tendency in air for the first time. The results showed that carbon can effectively prevent ZVAl from aging in the air, and even more intriguing is that AC and CNTs can maintain the activity of ZVAl for up to 3 months. Different species of carbon affect ZVAl's anti-aging capability in disparate ways. Among these, AC works by shielding, and CNTs modulate the surface functional groups. Although high ambient humidity impairs the aging resistance of ZVAl, calcination could enhance the aging resistance of ZVAl to some extent at higher humidity levels (40 %). Furthermore, compared with organic pollutants, all five 15d-aged C@ZVAl showed excellent removal properties with hardly any residue for inorganic pollutants. In conclusion, carbon modification can provide a solution for ZVAl to resist aging and preservation, and promote its wide application in the environmental field.