Effect of iron doping on nickel aluminate photocatalytic activity towards the degradation of methylene blue under visible and UV light

Abstract

The major issue that industries have is the degradation of organic dye in wastewater. In this study, we introduce an iron-doped spinel-type photocatalyst for dye degradation. Due to advantages like a lower band gap, and favorable magnetic characteristics, iron-doped nickel aluminate can be a viable catalyst for dye degradation. Nickel aluminate and iron-doped Nickel aluminate NiAl2-xFexO4 (x = 0.05, 0.1, 0.5, and 1.0) were synthesized by the sol-gel method using citric acid as a capping agent. The obtained samples were calcined at 800 °C for 4 h. The spinel was characterized using X-ray diffraction (XRD) which helped in the identification of the purity of the phase and the calculation of the average crystallite size. Fourier Transform Infrared (FT-IR) spectra confirmed the presence of iron in the octahedral site; (SEM-EDAX) Scanning Electron Microscopy facilitated the surface morphology and Energy-Dispersive X-ray analysis provided the elemental confirmation and UV-DRS techniques assisted in the calculation of the band gap using the Tauc plot method. Photocatalytic efficiency was investigated against the cationic dye Methylene blue under UV and Visible light. The results showed degradation of 94.25% under UV light and 83.51% under visible light in 90 min and 150 min respectively using iron-doped nickel aluminate.