Hybrid heterogeneous decontamination of polluted organic effluents using tailoring Fe2O3-ZnO over rGO via cutting-edge cold plasma technology

Regarding limited drinking water resources and also increasing pollution production rate from various industries, wastewater treatment methods have attracted considerable attention. Herein, sono-photodegradation of methylene blue (MB) was investigated over plasma-treated Fe2O3-ZnO/rGO (denoted as Fe2O3-ZnO/rGO (P)). Characterization of the photocatalysts was evaluated by XRD, FESEM, EDX, HRTEM, SAED, BET-BJH, DRS, and PL analyses. The defects, revealed by SAED, are related to thermal reduction and residual functional groups on rGO sheets. TEM and dot-mapping analysis showed considerable enhancement in the distribution of active phases on rGO. Furthermore, plasma treatment enhanced the contact area between nanoparticles and rGO sheets. BET-BJH represented Fe2O3-ZnO/rGO (P) as a mesoporous composite appropriate for degradation reaction. Moreover, the specific surface areas were 77 and 63 m2/g and total pore volumes were 109 and 84 cm3/g, for Fe2O3-ZnO/rGO and Fe2O3-ZnO/rGO (P) catalysts, respectively. The reason is that large clusters on the surface have been crushed and consequently blocked micropores. Due to more contact area in the plasma-treated sample, the recombination of photoinduced charges was declined, as in the condition of 20 mg/L initial MB concentration and 1g/L catalyst dosage, degradation reached from 83.4 to 97.5 %. Furthermore, plasma treatment caused a faster shift of the photogenerated charge into the graphene lattice. Plasma-treated Fe2O3-ZnO/rGO showed good reusability and degradation was 89.3 % after 5 runs.

Automated summary

This study investigates the sono-photodegradation of methylene blue using plasma-treated Fe2O3-ZnO/rGO as a photocatalyst. The plasma treatment enhances the contact area between nanoparticles and rGO sheets, leading to improved degradation performance. The plasma-treated Fe2O3-ZnO/rGO also exhibits good reusability, making it a promising catalyst for wastewater treatment.