A comprehensive study on dual functionality of MgCo₂O₄: synthesized by efficient auto-combustion method for photocatalytic and antibacterial application

Abstract In the present work, we report for the first time the photocatalytic degradation of Methylene blue (MB) dye under tungsten bulb (TB) for water purification, along with the antibacterial properties of spinel MgCo 2 O 4 (MgCo) synthesised by a facile solution combustion method. The phase purity of the prepared samples was analyzed using X-ray diffraction, Field Emission Scanning Electron Microscope (FESEM), Transmission Electron MIcroscope (TEM) and Fourier Transform Infrared Spectroscopy (FTIR). The compositional analysis was performed with the help of X-ray Photoelectron Spectrometer (XPS) and Energy Dispersive X-Ray Spectroscopy (EDS). Additionally, the DRS analysis gave more insight into the prepared material, from which the band gap was calculated as 1.25 eV. The photocatalytic degradation of MB under different light sources for different pH was studied, which showed a percentage degradation of 96.73% in 90 min after the irradiation by a TB (500 Watts) for a catalyst dosage of 25 mg. Additionally, the material exhibited excellent reusability, maintaining an efficiency of 94.2% even after five consecutive cycles. The antibacterial activity was tested against both Gram-positive and Gram-negative bacteria by the Agar well diffusion method, showing strong inhibition for all four tested strains. The highest inhibition zone was observed for Bacillus subtilis, which was again subjected to concentration studies by well diffusion as well as minimum inhibition concentration. The results indicate that MgCo holds significant potential for photocatalytic degradation and antibacterial applications.