In this study, Fe2O3 (hematite) nanoparticles with different crystallite sizes (40–59 nm) were synthesized from Egyptian insecticide cans using the combustion method. The organic fuels were urea, glycine, L-alanine, and Lvaline. Fe2O3 nanoparticles were characterized utilizing different devices such as BET, PL, FT-IR, XRD, HR-TEM, FE-SEM, UV–Vis, and DTG. Crystal violet (CV) and methylene blue (MB) dyes were efficiently removed from aqueous solution by photocatalytic degradation under UV irradiation in the presence of Fe2O3 and H2O2. The % degradation of 50 mL crystal violet or methylene blue dye (20 mg/L) using 0.1 g Fe2O3 in the presence of H2O2 was 100% after 30 or 40 min, respectively. Also, the degradation processes are fitted well with the first order model. Besides, the photocatalytic activity of Fe2O3 unaltered even after itwas reused three times. Hence, the synthesized Fe2O3 nanoparticles can be considered a promising and efficient photocatalyst for the degradation of crystal violet and methylene blue dyes.