Bimetallic Ag/Fe-MOG derived flake-like Ag2O/Fe2O3 p-n heterojunction for efficient photodegradation organic pollutants within a wide pH range.

In this paper, we reported a facile and clean strategy to prepare the flake-like Ag 2 O/Fe 2 O 3 bimetallic p-n heterojunction composites for photodegradation organic pollutants. The surface morphology, crystal structure, chemical composition and optical properties of Ag 2 O/Fe 2 O 3 were characterized by SEM, high-resolution TEM images with EDX spectra, XRD, XPS, FT-IR and UV–vis DRS spectra respectively. The formation of Ag 2 O/Fe 2 O 3 p-n heterojunction facilitated the interfacial transfer of electrons as well as the separation of charge carries. Hence, the as-synthesized Ag 2 O/Fe 2 O 3 -3 composites exhibited ultra-high photocatalytic activity. Under the experimental conditions of catalyst dosage of 0.4 mg mL−1 and irradiation time of 60 min, the degradation conversion rate of rhodamine B reached 96.1 %, which was 5.0 and 2.8 times of pure phase Ag 2 O and Fe 2 O 3 , respectively. Meanwhile, the degradation performance of Ag 2 O/Fe 2 O 3 -3 was not limited by pH, and it can achieve high degradation efficiency under 3–11. In addition, Ag 2 O/Fe 2 O 3 -3 also showed superb degradation ability for other common anionic dyes, cationic dyes and antibiotics. XPS and FT-IR spectra showed that Ag 2 O/Fe 2 O 3 -3 retained a carbon skeleton that facilitated electron transport and light absorption conversion. And the analyses of quenching experiment and EPR demonstrated •O 2 −, •OH and h + were crucial reactive oxidant species contributing to the rapid organic pollutant degradation. This work provides new insights into obtaining p-n photocatalysts heterojunction with excellent catalytic activity for removing organic pollutants from wastewater. • Ag 2 O/Fe 2 O 3 -x p-n heterojunction was firstly prepared via facile templating method. • Ag 2 O-based p-n heterojunction with Carbon skeleton was synthesized for the first time. • Ag 2 O/Fe 2 O 3 -3 can achieve high degradation efficiency of Rh B at pH 3–11. [ABSTRACT FROM AUTHOR]