Synthesis of mesoporous composites based on α-Fe2O3/NiO nanowires for the photocatalytic degradation of rhodamine B dye

Abstract

The development of an active photocatalyst based on semiconducting materials having desired features with effective charge carrier transformation is essential for better photocatalyst utilization with optimized performance. In this work, we prepared different composites based on mesoporous α-Fe₂O₃/NiO nanowires using a facile hydrothermal method. The as-prepared samples were evaluated using different characterization techniques to study their crystallinity, morphologies, chemical compositions, and photocatalytic properties towards Rhodamine B dye degradation under visible light illumination. Compared to investigated samples, the as-prepared S2-based α-Fe₂O₃/NiO composite exhibits an enhanced photocatalytic efficiency of 96% in a short time interval of 100 minutes owing to its large surface area and mesoporous structure, synergistic with the catalytic effect of α-Fe₂O₃ and the formation of a p/n junction at the interface of α-Fe₂O₃ and NiO. The photocatalyst based on the α-Fe₂O₃/NiO composite also exhibited satisfactory stability and recyclability, and the removal efficiency was 92% even after the fifth cycle, outperforming the previously reported metal oxide based heterostructures and commercial TiO₂ (P25). The main reactive species for the degradation of the RhB dye were superoxide radicals generated under light illumination. Furthermore, a related photocatalytic mechanism is proposed.