Efficient photocatalytic degradation of malachite green dye using facilely synthesized hematite nanoparticles from Egyptian insecticide cans

Abstract In the present study, a combustion method was applied for the production of hematite nanoparticles from Egyptian iron waste using l -arginine (The sample was named HA) and glutamine (The sample named HG) as organic fuels, respectively. XRD confirmed that the HA and HG products have crystallite sizes of 48 and 56 nm, respectively. Also, HR-TEM demonstrated that spherical and irregular shapes have an average diameter of 45 and 59 nm were observed in the HA and HG samples, respectively. Besides, FE-SEM elucidated that spherical and irregular shapes have an average size of 142 and 196 nm were observed in the HA and HG samples, respectively. In addition, FT-IR confirmed that the peaks which were detected at 518 and 430 cm-1 are because of vibrations of Fe–O bond. Moreover, the value of the energy gap for the HA and HG samples was 1.00 and 1.45 eV, respectively. Furthermore, the PL emission spectra elucidated that the emission intensity of the HA sample was less than that of the HG sample. So, e−/h+ recombination rate of the HA sample was less than that of the HG sample. Hence, the photocatalytic degradation of malachite green dye using the HA sample was larger than that using the HG sample. In the absence of H2O2, the % degradation of malachite green dye under the influence of UV using HA and HG samples was 46.29 and 39.72 % after 3 h, respectively. Also, in the presence of H2O2, the % degradation of malachite green dye under the influence of UV using HA and HG samples was 100 % after 60 and 70 min, respectively.