Water pollution remediation: synthesis of gray-Tio₂/Zno/α-Fe₂o₃ ternary composite for the photocatalytic degradation of Direct Red 28 dye under solar light

Based on an appropriate procedure and little toxicity to living things, photocatalytic degradation is noted as one of the best ways to address environmental problems, especially for the effective breakdown of organic pollutants. The present work was aimed at investigating the photocatalytic performance of oxides as ternary nanocomposites in the degradation of Direct Red 28 dye in aqueous solution under solar light. The solvothermal process was employed for the synthesis of Gray-TiO₂/ZnO/α-Fe₂O₃ composites. The constructed composite was characterized by means of FTIR, PL, XRD, and SEM, among other methods. The photocatalytic activity of the composite enhances up to 98.82% at pH 3, while it reduces up to 72.21% with an increasing concentration of initial dye at 30 mgL⁻¹. The synthesized composite had a degradation efficiency of around 99% for Direct Red 28 dye since its recombination rate was high. After the four cyclic runs of the used composite, 85% degradation of Direct Red 28 was observed, which substantiates that the Gray-TiO₂/ZnO/α-Fe₂O₃ composite is a stable and efficient catalyst.