Constructing a carbon sphere-embedded Fe0 for accelerating electro-peroxone oxidation effectively: The dual catalytic role with O3 and H2O2

Recognizing the high energy consumption for in-situ generation of H2O2 and low mass transfer of O3 in electro-peroxone (EP), Fe0 embedded in carbon sphere (Fe0@CS) was synthesized to fulfill the efficient treatment of various pollutants. At optimal condition, the degradation and mineralization of 100 mg/L phenol were 100% with k (0.20 min−1) at 15 min and 72.1% at 60 min with iron dissolution (1.61 mg/L) and low energy consumption (0.067 kWh (g TOC)−1). The utilization efficiency of O3 and H2O2 increased by 1.9 – 11.5% and 16.8 – 27.1%, respectively. Fe2+ originated from the faster H2O2 corrosion, initiated heterogeneous Fenton-like and catalytic ozonation reaction. The quenching and electron paramagnetic resonance experiments manifested the existence and mutual transformation of •OH, •O2- and 1O2, among which •OH was dominant. Fe0@CS/EP realized the simultaneous catalysis of O3 and H2O2 over wide pH 3 – 10, which had broad prospects for wastewater purification.