Author(s):
Sajid Hussain, Rakesh Kumar Singh, Ashish Kumar, Singh Sonu Kumar, Nishant Kumar, Gaurav Kumar, Abhay Kumar Aman,

Abstract:
This research demonstrates the sustainable synthesis of crystalline nanosilica (SiO₂) from rice husk, an agricultural waste, via a cost-effective route. The nanosilica was integrated with ferrites and polyvinylidene fluoride (PVDF) to create a magnetic nanocomposite using injection moulding equipment. X-ray diffraction (XRD) confirmed the crystallinity of the SiO₂, while scanning electron microscopy (SEM) revealed nanoscale particle morphology. Fourier-transform infrared spectroscopy (FTIR) identified Si–O–Si functional groups, validating the silica structure. UV–Vis spectroscopy showed strong UV absorption, indicating potential catalytic applications, and low visible light absorption. Tauc plot analysis yielded the direct and indirect band gaps. The indirect band gap was determined to be 1.73 eV, and subsequently direct band gap is 1.88 eV, which is similar to semiconductor electronics materials. Magnetic measurements showed diamagnetic behavior for pure SiO₂ and ferromagnetic properties for the SiO₂–ferrite–PVDF nanocomposite, exhibiting distinct hysteresis loops. These results highlight the successful valorization of rice husk-derived nanosilica from agriculture waste in producing polymer magnets with potential applications in semiconductor electronics, catalytic activity and biomedical science.

Pages: 638-648

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