Black nZVI particles appeared immediately after introducing the
first fewdrops of NaBH4 solution. After the addition of NaBH4 solu-
tion, themixturewas stirred for an additional 20min. nZVI particles
were collected andwashed thricewith iso-propanol to prevent oxi-
dation.Deionized deoxygenatedwater (spargedwith nitrogen)was
used to prepare aqueous solutions. nZVI synthesis was conducted
in an anaerobic chamber maintaining an O2-free environment by
purging with O2-free Ar (95% Ar:5% H2)