Synthesis of Ag-Cu co-doping sponge iron-based trimetal for boosting simultaneous degradation of combined pollutants

Abstract

To date, zero-valent iron (ZVI)-based technique has encountered a baffle, challenging simultaneous detoxification of refractory rhodamine B (RhB) and p-nitrophenol (PNP) possessing strong electronwithdrawing nitro-group. In this study, we synthesized Ag-Cu decorated sponge iron (s-Fe0)-based trimetal for simultaneous degradation of RhB and PNP. The results show that Cu-Ag co-doping s-Fe0 (s-Fe0-(Cu-Ag)) achieves approx. 90.6 % of maximized removal of RhB; the preferred s-Fe0-(5 wt%Cu-1 wt%Ag) assisted with 6 L/min aeration rate simultaneously declines RhB and PNP within 10 recycling tests; non-aeration process obtains a complete reduction of PNP as well as merely approx. 23.9 % removal of RhB. Moreover, the Cu-Ag microstructure covering s-Fe0-(Cu-Ag) has been characterized in detail. Furthermore, the electron spin resonance (ESR) spectra have been applied to investigate simultaneous generation of reactive oxygen species (ROSs) and hydrogen radicals ([H]abs) over s-Fe0-(Cu-Ag). To our best knowledge, this is the first study reporting the enhanced bifunctional catalysis of s-Fe0-(Cu-Ag)/O2 for simultaneous degradation of RhB and PNP.