Long-lasting activity of Fe0-C internal microelectrolysis-Fenton system assisted by Fe@C-montmorillonites nanocomposites

Abstract Core/shell type Fe 0 @carbon (Fe@C) nanocomposites inserted in the interlayer space of montmorillonites (MMT) is prepared by one-step pyrolysis of Fe-metal organic frameworks and MMT. Fe@C-MMT serves as Fenton-like catalyst to degrade organic pollutants based on internal microelectrolysis (IME)-Fenton reactions. The MMT coat accelerates galvanic corrosion of Fe 0 to facilitate in-situ generation of Fe 2+ and achieves self-regulation of solution pH. Strengthened elimination of phenol and methyl orange with high mineralization efficiency (80%) at initial pH 3–6.5 was achieved in Fe@C-MMT-H 2 O 2 system compared to Fe@C-, ZVI-, and commercial Fe-C-H 2 O 2 systems. The MMT coat retards contact of Fe 0 and Fe(II) species on Fe@C-MMT surface with H 2 O 2 , leading to rate-controlling consumption of H 2 O 2 to keep the long-lasting efficiency of the IME-Fenton system. Fe@C-MMT suspension with 10 mM of H 2 O 2 can continuously degrade organic pollutants within 40 h. Fe@C-MMT can be recycled for five times and shows good resistance to oxygen and acid corrosion.