Versatile and biomass synthesis of iron-based nanoparticles supported on carbon matrix with high iron content and tunable reactivity

摘要

Iron-based nanoparticles supported on carbon (FeNPs@C) have enormous potential for environmental applications. Reported is a biomass-based method for FeNP@C synthesis that involves pyrolysis of bleached wood fiber pre-mixed with Fe₃O₄ nanoparticles. This method allows synthesis of iron-based nanoparticles with tunable chemical reactivity by changing the pyrolysis temperature. The FeNP@C synthesized at a pyrolysis temperature of 500 °C (FeNP@C-500) reacts violently (pyrophoric) when exposed to air, while FeNP@C prepared at 800 °C (FeNP@C-800) remains stable in ambient condition for at least 3 months. The FeNPs in FeNP@C-800 are mostly below 50 nm in diameter and are surrounded by carbon. The immediate carbon layer (within 5–15 nm radius) on the FeNPs is graphitized. Proof-of-concept environmental applications of FeNPs@C-800 were demonstrated by Rhodamine 6G and arsenate (V) removal from water. This biomass-based method provides an effective way for iron-based nanoparticle fabrication and biomass utilization.