Advancing the eradication of harmful dyes through stereolithography-produced 3D floating photocatalysis: Exploiting the synergistic potential of graphene/MnO2/Fe3O4 hybrid nanomaterials

Abstract

The utilization of heterogeneous photocatalysis for the breakdown of organic pollutants in wastewater has become increasingly popular as an alternative treatment method, offering rapid mineralization of organic compounds. However, the challenges lie in the recycling and recovery processes. To overcome this hurdle, a novel 3D-printed hybrid photocatalyst composed of graphene/MnO2/Fe3O4 was developed through an ex-situ approach. Comprehensive property evaluations were conducted, and the catalyst was employed in the creation of a 3D photocatalyst designed for MB dye removal under direct sunlight, facilitating the easy separation of the used catalyst. Further enhancement of its photocatalytic activity was achieved through carbonization, rendering it promising for wastewater treatment owing to its ordered structure and facile recovery. Notably, the developed 3D photocatalyst exhibited a significant improvement in MB dye degradation compared to powder samples. It showcased effective degradation of 10 ppm of MB dye within a mere 120 min of sunlight exposure. Radical trapping analysis indicated that the high photocatalytic degradation was predominantly attributed to the photogenerated superoxide radicals. Consequently, the 3D printed photocatalyst demonstrated exceptional reusability and sustained efficiency in MB dye degradation without any discernible decrease in catalytic activity. The augmented photocatalytic degradation was governed by the generation of photogenerated charge carriers through reduction and oxidation reactions. This research holds promise for the creation of an economical, user-friendly, and highly efficient 3D printed hybrid photocatalyst with synergistic applications in water purification.