Removal of nitrate ions from aqueous solution using zero-valent iron nanoparticles supported on high surface area nanographenes

In this manuscript, zero-valent iron nanoparticles (ZVINPs) were synthesized, and then supported on high surface area nanographenes (NGs) to prepare a stable ZVINP/NG nanocomposite. XRD measurements showed the stabilization of the ZVINPs upon their support on NGs, which enhanced their activity. The ZVINP/NG nanocomposite was used for the catalytic reduction of nitrate ions in model solution, and the results showed the dependency of the removal process on the ratio of ZVINPs to NGs in the nanocomposite, time of removal, and solution pH. The effect of ultrasonication was also explored, and the results showed that ultrasonication could significantly decrease the removal time required by the nanocomposite. The mechanism of nitrate reduction by ZVINP/NG nanocomposite was studied, and the results showed the conversion of nitrate to nitrite and/or ammonia, then to nitrogen gas.