Sustainable synthesis of hollow Cu-loaded poly(m-phenylenediamine) particles and their application for arsenic removal

Abstract

A new Cu-catalyzed air oxidation method was successfully developed to prepare Cu-loaded poly(m-phenylenediamine) (PmPD) with monomer conversion rates close to 100%. The polymerization process was examined by the in situ tracking of open-circuit potential (OCP) and pH. The product was characterized with scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD). The results show that the Cu catalytic effect in the air oxidation was responsible for the great enhancement of monomers conversion rates. On increasing Cu addition, PmPD particles tended to form hollow microstructures, which may result from a dehydration effect. Furthermore, the as-obtained samples have superior arsenic(V) removal performance in aqueous solution. The adsorption equilibrium can be rapidly reached within 10 min. Higher loadings of Cu particles exhibited an improved arsenic(V) removal capability of 27.4 mg g⁻¹, much higher than in other reports. The adsorption behavior can be well described by Freundlich and pseudo-second-order models. The related possible mechanisms have been explored carefully.