Nanoscale Zero‐Valent Iron Particles Supported on Reduced Graphene Oxides by Using a Plasma Technique and Their Application for Removal of Heavy‐Metal Ions

Nanoscale zero‐valent iron particles supported on reduced graphene oxides (NZVI/rGOs) from spent graphene oxide (GO)‐bound iron ions were developed by using a hydrogen/argon plasma reduction method to improve the reactivity and stability of NZVI. The NZVI/rGOs exhibited excellent water treatment performance with excellent removal capacities of 187.16 and 396.37 mg g −1 for chromium and lead, respectively. Moreover, the NZVI/rGOs could be regenerated by plasma treatment and maintained high removal ability after four cycles. X‐ray photoelectron spectroscopy analysis results implied that the removal mechanisms could be attributed to adsorption/precipitation, reduction, or both. Such multiple removal mechanisms by the NZVI/rGOs were attributed to the reduction ability of the NZVI particles and the role of dispersing and stabilizing abilities of the rGOs. The results indicated that the NZVI/rGOs prepared by a hydrogen/argon plasma reduction method might be an effective composite for heavy‐metal‐ion removal.