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

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-Fe 0 )-based trimetal for simultaneous degradation of RhB and PNP. The results show that Cu-Ag co-doping s-Fe 0 (s-Fe 0 -(Cu-Ag)) achieves approx. 90.6 % of maximized removal of RhB; the preferred s-Fe 0 -(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-Fe 0 -(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 (ROS s ) and hydrogen radicals ([H] abs ) over s-Fe 0 -(Cu-Ag). To our best knowledge, this is the first study reporting the enhanced bifunctional catalysis of s-Fe 0 -(Cu-Ag)/O 2 for simultaneous degradation of RhB and PNP. • Ag-Cu-doped sponge iron (s-Fe 0 -(Cu-Ag)) could simultaneously detoxify RhB and PNP. • s-Fe 0 -(Cu-Ag) prompts reactive oxygen species (ROSs) and activated hydrogen atoms ([H]*). • Electron spin resonance (ESR) spectra verify the generation of [H]* , • OH, • O 2 - and 1 O 2 . • ROSs and [H]* achieve rapid oxidation of RhB and reduction of PNP, respectively.