Publications

The aim of this work is to fabricate ZnO–NiO–Mn2O3 nanocomposites with exceptional features and improved physical and magnetic properties, compared to their pure counterparts. The pure oxides ZnO, NiO and Mn2O3 nanoparticles (NPs) were first synthesized via co-precipitation method. The as-prepared pure oxides were then ball milled in different mass percentages to form four ternary metal oxide nanocomposites (NCs): C1 (0.33 ZnO, 0.33 NiO, 0.33 Mn2O3), C2 (0.66 ZnO, 0.166 NiO, 0.166 Mn2O3), C3 (0.166 ZnO, 0.66 NiO, 0.166 Mn2O3), and C4 (0.166 ZnO, 0.166 NiO, 0.66 Mn2O3). Structurally, X-ray powder diffraction (XRD) analysis confirmed the formation of pure ZnO, NiO and Mn2O3 with hexagonal (a = b = 3.247 Å, c = 5.201 Å), FCC (a = b = c = 4.174 Å) and BCC (a = b = c = 9.408 Å) crystal structures, respectively. In NCs, the formation of spinel oxides (ZnMn2O4, NiMn2O4 and Mn3O4) of tetragonal structures was revealed through Rietveld refinement. Through transmission electron microscopy (TEM), the versatile morphology of NPs in the formed NCs was suspected validating the incorporation of multi-oxide phases in one matrix. The average particle size of pure ZnO (<d>  = 70.65 nm), pure NiO (<d>  = 29.61 nm) and pure Mn2O3 (<d>  = 77.132 nm) NPs were also estimated via TEM. For elemental composition, energy-dispersive X-ray revealed the presence of Zn, Ni, Mn, and O elements in the four NCs and their corresponding atomic percent (at.%) were in good agreement with XRD results. Raman analysis manifests eight, six and three symmetry phonon-vibration modes in pure ZnO, NiO and Mn2O3 NPs, respectively. The A1g (665 cm−1) and T2g (475 cm−1) symmetry bands in mico-Raman analysis confirmed the formation of tetragonal ZnMn2O4 in the four nanocomposites. DC-conductivity was used to investigate the conduction mechanisms in pure NPs and NCs along with their I–V curves. The semiconducting behavior of the seven samples was affirmed, where C1 showed the best dc-conductivity (σ=1.347×10−6S/m) . Vibrating sample magnetometer (VSM) analysis reported the diamagnetic, antiferromagnetic, and paramagnetic nature of ZnO, NiO and Mn2O3, respectively. The antiferromagnetic nature of NCs C1, C2 and C3 was also exhibited. VSM disclosed the ferromagnetic nature of C4 (squareness ratio: s = 0.2034) attributed to the formation of Mn3O4, with high percentage in this NC. The maximum UV-induced photodegradation efficiency of pure ZnO, NiO, Mn2O3 NPs and NC C1 towards the synthetic dye Rhodamine B (Rh B) was tested at pH = 5.5 and the corresponding obtained % degradation were 85.25%, 7.95%, 39.58% and 36.71% respectively.