Dye contamination is becoming a more significant environmental challenge with the development of the textile industry. Scientists from all over the world are working hard to create new, more efficient ways to reduce environmental pollution through environmentally friendly synthesis techniques. In this regard, hematite (α-Fe2O3) nanoparticles have been synthesized by the novel, quick, cheap, and environmentally safe microplasma technique for the photodegradation of rhodamine-B under direct sunlight. Thus, the synthesized α-Fe2O3 nanoparticles were characterized by various characterization techniques such as X-Ray diffraction (XRD), scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR), and ultraviolet-visible spectroscopy (UV-Vis spectroscopy). The structural and optical properties were found to vary with changing precursor concentrations. We measured the photocatalytic decolorization efficiency of synthesized hematite (α-Fe2O3) nanoparticles for rhodamine-B dye under direct sunlight. It was found that α-Fe2O3 nanoparticles exhibited a decolorization capability with 73.75% decolorization of the dye at the rate of 0.04305 g.mg-1.min-1 after 100 minutes of irradiation, exhibiting excellent performance to remove organic contaminants from wastewater.