The novel magnetic Ti-Sr ferrite@SiO2 core-shell nanospheres enfolding mesoporous SiO2 cores were synthesized employing surfactant-assisted ultrasonication process. Whereas, the reversal of core-shell i.e. SiO2@Ti-Sr ferrite core-shell nanospheres were obtained via surfactant assisted direct precipitation of SiO2 onto Ti-Sr ferrite NPs. The surface morphology, phase composition, crystallinity, magnetic properties, chemical composition and valence state were characterized by TEM, SEM-EDS, FT-IR, XRD, VSM, DLS, BET and XPS analytical techniques. The saturation magnetization (Ms) was 5.63 and 3.87 emu/g for Ti-Sr ferrite@SiO2 and SiO2@Ti-Sr ferrite, respectively revealing the dependency of magnetic properties on the core-shell reversal. The core-shell nanocomposite with SiO2 shell exhibited higher BET specific surface area of 106.88 m2/g than its reversal core-shell nanocomposite (94.87 m2/g). The photocatalytic potential of the pristine NPs and their core-shell nanospheres was studied for the degradation of two nitroaromatic compounds viz. pendimethalin and p-nitrophenol. SiO2@Ti-Sr ferrite core-shell nanohybrid exhibited the higher photocatalytic efficiency as compared to Ti-Sr ferrite@SiO2 for the degradation of pendimethalin(91%) and p-nitrophenol(86%). The apparent rate constant for pendimethalin (0.0261 min-1) was about 1.29 times as higher than that of p-nitrophenol (0.0201 min-1) which confirmed the fast photocatalytic reaction for the pendimethalin. The scavenging experiment revealed that O2.- radicals were the main reactive species involved in the photodegradation of nitroaromatic pollutants. The degradation pathways were studied by gas chromatography-mass spectrometry.

Mechanistic insight into structural, magnetic, optical and photocatalytic properties of core-shell reversal of tri-metallic titanium strontium ferrite-silica nanocomposites

ACS Fall 2021

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.