Synthesis of NFO-immobilized yeast nanobiocomposite for ultrasound-assisted photo-fenton degradation of methylene blue by using central composite design

Abstract

In this study, we synthesized nano-NiFe2O4-immobilized Saccharomyces cerevisiae yeast composites (NFO-SC) and investigated their photo-deterioration efficiency for methylene blue (MB) using central composite design (CCD). The morphological features of NFO-SC were comprehensively characterized through scanning electron microscopy (SEM), UV–VIS spectroscopy, Fourier-transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). Initial XRD analysis of pristine NFO indicated an average particle size of 20 nm. Subsequent XRD, FTIR, SEM, and UV–VIS analyses were performed before and after immobilization, confirming the surface modification of yeast cells by NFO. The XRD results for NFO-SC revealed a reduced average particle size of nickel nano-ferrite (NFO) to 14 nm. The NiFe2O4-SC composite exhibited an impressive 99% MB deterioration efficiency under optimized conditions: 0.020 g of NFO-SC dosage, pH 4.5, initial MB concentration of 20 mg/L, and a photo-irradiation time of 120 min. Photo-catalytic activity was evaluated through UV–VIS spectroscopy and FTIR analysis, demonstrating that the NiFe2O4-SC composite outperformed pristine yeast and pure NFO in MB degradation efficiency. This study highlights the potential of the NiFe2O4-SC composite as an photo-catalyst for dye degradation, showcasing its promise for applications in environmental remediation processes.