Photocatalytic activity of ZnFe2O4/NiO nanocomposites carried out under UV irradiation. Issue 20 (15th October 2022) - Aridi, Amani
Abstract: The photocatalytic activity of zinc ferrite (ZnFe2 O4 ) nanoparticles (NPs) is suppressed by the rapid recombination of the photogenerated electron-hole pair. Herein to achieve electron-hole separation, ZnFe2 O4 was combined with nickel oxide (NiO) NPs to produce (1-x)ZnFe2 O4 /xNiO nanocomposites (NCs) with enhanced photocatalytic activity where the weight fraction (x) ranged between 0.1 and 0.5. The photocatalytic performance of ZnFe2 O4 /NiO NCs was evaluated in the degradation of nitrobenzene under UV irradiation at 254 nm and compared to the activity of pure ZnFe2 O4 and NiO NPs. Phase purity tested by X-ray diffraction (XRD) confirmed the sole presence of ZnFe2 O4 and NiO. The cubic shape with rounded edges morphology of the prepared samples was revealed in transmission electron microscopy (TEM). The specific surface area of ZnFe2 O4 /NiO NCs obtained by N2 adsorption-desorption isotherms ranged between 12 and 17 m 2 /g. The photocatalytic activity of pure NPs and NCs in the degradation of nitrobenzene under UV irradiation was also studied; maximum efficiency was achieved with the (1-x)ZnFe2 O4 /xNiO NCs where x = 0.3. This was due to the low recombination rate of electron-hole pairs confirmed by photoluminescence (PL) spectroscopy. Several other factors (catalyst dosage, pH and temperature) affecting the degradation efficiency were also investigated. The optimum experimental conditions were applied to identify the products of the degradation reaction. Comparison studies between the photocatalytic activity of ZnFe2 O4 /NiO NCs and ZnFe2 O4 /Mn2 O3 NCs were reported.