Polyoxometalate-based graphitic carbon nitride for reduction of toxic nitro aromatic compounds in water

Abstract

The present study focuses on the development of an impressive way to eliminate toxic nitro aromatic compounds as hazardous industrial pollutants using polyoxometalate-based composites. For this purpose, transition metal substituted Keggin-type polyoxometalates were integrated on modified protonated graphitic carbon nitride (POMs@g-C3N4) via an electrostatic self-assembly strategy. These stable compounds are characterized by different techniques and used in the reduction of toxic nitro aromatic compounds. Among Cr, Mn, Fe, Co, Ni, Cu, and Zn, the composite containing copper substituted Keggin-type polyoxometalate (CuPOM@g-C3N4) presents the most respectable catalytic activity in these reduction reactions. Moreover, this efficient catalytic system is applied in the reduction of different toxic nitro aromatic compounds into the amino aromatic analogues with appropriate conversions and reaction times. Kinetic studies are also used to determine their apparent rate constants. This process is easy, low-cost, non-toxic, high potential catalytic performance, and environmental friendliness that could be accomplished in water as solvent and at room temperature.