Efficient Photocatalytic Degradation of Congo Red Dye Using Facilely Synthesized and Characterized MgAl2O4 Nanoparticles

ACS Omega. 2024 Jan 19;9(4):4870-4880. doi: 10.1021/acsomega.3c08485. eCollection 2024 Jan 30.

Abstract

The discharge of congo red dye into water sources by factories has been associated with a range of health concerns, such as cancer, redness, skin irritation, and allergic reactions. As a result, this research focused on the cost-effective and straightforward production of MgAl2O4 nanoparticles by using the Pechini sol-gel process. Subsequently, these nanoparticles were employed for the successful photocatalytic decomposition of congo red dye. Moreover, extensive characterization of the fabricated MgAl2O4 nanoparticles was conducted through diverse methodologies, which included Fourier-transform infrared spectroscopy, ultraviolet-visible spectrophotometry, high-resolution transmission electron microscopy (HR-TEM), field-emission scanning electron microscopy (FE-SEM), and powder X-ray diffraction (XRD). Furthermore, the XRD analysis disclosed that the average crystal size of the produced MgAl2O4 nanoparticles is 10.36 nm, and their optical energy gap was determined to be 3.71 eV. The FE-SEM examination unveiled a combination of spherical and disorganized structures with a 0.14 μm average grain size. HR-TEM analysis, in turn, revealed that the fabricated MgAl2O4 nanoparticles were composed of minuscule spherical particles with an average diameter of 8.75 nm. The maximum degradation of 50 mL of congo red dye at a concentration of 25 mg/L reached 99.27% within 80 min at a pH of 3. Additionally, the findings confirmed the consistent decomposition activity toward congo red dye even after four cycles, thereby validating the effectiveness and reusability of the MgAl2O4 nanoparticles that were developed in this study.