One-Pot Phyto-Mediated Synthesis of Fe[sub.2]O[sub.3]/Fe[sub.3]O[sub.4] Binary Mixed Nanocomposite Efficiently Applied in Wastewater Remediation by Photo-Fenton Reaction

A binary Fe[sub.2]O[sub.3]/Fe[sub.3]O[sub.4] mixed nanocomposite was prepared by phyto-mediated avenue to be suited in the photo-Fenton photodegradation of methylene blue (MB) in the presence of H[sub.2]O[sub.2]. XRD and SEM analyses illustrated that Fe[sub.2]O[sub.3] nanoparticles of average crystallite size 8.43 nm were successfully mixed with plate-like aggregates of Fe[sub.3]O[sub.4] with a 15.1 nm average crystallite size. Moreover, SEM images showed a porous morphology for the binary Fe[sub.2]O[sub.3]/Fe[sub.3]O[sub.4] mixed nanocomposite that is favorable for a photocatalyst. EDX and elemental mapping showed intense iron and oxygen peaks, confirming composite purity and symmetrical distribution. FTIR analysis displayed the distinct Fe-O assignments. Moreover, the isotherm of the developed nanocomposite showed slit-shaped pores in loose particulates within plate-like aggregates and a mesoporous pore-size distribution. Thermal gravimetric analysis (TGA) indicated the high thermal stability of the prepared Fe[sub.2]O[sub.3]/Fe[sub.3]O[sub.4] binary nanocomposite. The optical properties illustrated a narrowing in the band gab (Eg = 2.92 eV) that enabled considerable absorption in the visible region of solar light. Suiting the developed binary Fe[sub.2]O[sub.3]/Fe[sub.3]O[sub.4] nanocomposite in the photo-Fenton reaction along with H[sub.2]O[sub.2] supplied higher productivity of active oxidizing species and accordingly a higher degradation efficacy of MB. The solar-driven photodegradation reactions were conducted and the estimated rate constants were 0.002, 0.0047, and 0.0143 min[sup.−1] when using the Fe[sub.2]O[sub.3]/Fe[sub.3]O[sub.4] nanocomposite, pure H[sub.2]O[sub.2], and the Fe[sub.2]O[sub.3]/Fe[sub.3]O[sub.4]/H[sub.2]O[sub.2] hybrid catalyst, respectively. Therefore, suiting the developed binary Fe[sub.2]O[sub.3]/Fe[sub.3]O[sub.4] nanocomposite and H[sub.2]O[sub.2] in photo-Fenton reaction supplied higher productivity of active oxidizing species and accordingly a higher degradation efficacy of MB. After being subjected to four photo-Fenton degradation cycles, the Fe[sub.2]O[sub.3]/Fe[sub.3]O[sub.4] nanocomposite catalyst still functioned admirably. Further evaluation of Fe[sub.2]O[sub.3]/Fe[sub.3]O[sub.4] nanocomposite in photocatalytic remediation of contaminated water using a mixture of MB and pyronine Y (PY) dyestuffs revealed substantial dye photodegradation efficiencies.