| Popis: |
Developing alternative green and sustainable technologies to prevent, reduce, and remove toxic dyes present in effluent generated by the textile industry is of global importance. In this study, magnetite (Fe _3 O _4 ) nanoparticles (MNPs) were successfully synthesized using a co-precipitation method that used Indigenous Banksia Ashbyi (BA) leaf extract in varying amounts (BA-MNP 1 to BA-MNP 4), to modulate particle size and size distribution. The formation of the MNPs was confirmed by a range of characterization techniques that included UV–visible spectrophotometry, Fourier transform infrared (FTIR) spectroscopy, x-ray diffraction (XRD) spectroscopy, thermo-gravimetric analysis (TGA) and scanning (FIBSEM) and high-resolution transmission (HRTEM) electron microscopy. The presence of the Fe–O bond located at 551 cm ^−1 in the FTIR spectra and XRD analysis of the samples confirmed the formation of crystalline MNPs. FIBSEM and HRTEM images of the BA-MNP 4 sample confirmed the MNPs were spherical (18 ± 5 nm) and tended to agglomerate. Moreover, UV–visible spectrophotometry revealed a board absorption band and an optical band-gap energy of 2.65 eV. The catalytic activity of BA-MNP 4 samples towards the degradation of a commercially available navy-blue RIT dye (BRD) were investigated under three operational senarios: 1) ultrasonic irradiation (US) + BRD; 2) BA-MNP 4 + BRD, and 3) US + BRD + BA-MNP 4. The investigation found there was an additive effect when US (80 W) was used in conjunction with BA-MNP 4 s during the dye degradation process. With no US, the BA-MNP 4 sample only achieved a dye degradation of 52% in 25 min. However, over the same period of time with US, the BA-MNP 4 sample achieved a dye degradation of 89.92%. In addition, kinetic modelling found the combined US and BA-MNP 4 process followed a pseudo-first-order kinetic model. |
