Highly efficient oxidation of aqueous contaminants by mesoporous graphitic carbon nitride supported copper phosphide with dual active sites

Abstract

Rational design of low-cost and high-efficient non-precious-metal based Fenton-like catalysts has drawn tremendous attention. Mesoporous graphitic carbon nitride (m-CN) supported copper phosphide (Cu3P@m-CN) catalysts were synthesized, and applied in organic oxidation using H2O2 as the oxidizing reagent. Cu3P@m-CN exhibited excellent stability and high activities toward various organic pollutants over a wide pH range. Removal efficiency of pollutants depends on catalyst type and loading, main operating parameters (pollutant concentration, H2O2 dosage, reaction temperature and solution pH) and different water matrices. Quenching, electron paramagnetic resonance and fluorescence tests confirm that HO• and O⋅− 2 /HO⋅ 2 serve as the main active species for pollutant degradation. The abundant cation (Cuδ+) and anion (Pδ− ) as the dual active sites in Cu3P synergistically activate H2O2. Cuδ+ can activate H2O2 and promote the Cu2+/Cu+ cycle by electron transfer. Pδ- has the ability to donate electrons, which can also activate H2O2 and regenerate Cu+ from Cu2+. Porous m-CN materials could not only improve the dispersibility of Cu3P nanoparticles, but also effectively promote electron transfer, thus enhancing the catalytic performance, superior to other traditional supports. Consequently, the work demonstrated that the combination of Cu3P and m-CN was a feasible strategy for preparation of effective catalysts toward mineralization of organic pollutants.