Behavior of Silica Nanoparticles Synthesized from Rice Husk Ash by the Sol-Gel Method as a Photocatalytic and Antibacterial Agent

A Alhadhrami; Gehad G Mohamed; Ahmed H Sadek; Sameh H Ismail; A A Ebnalwaled; Abdulraheem S A Almalki

doi:10.3390/ma15228211

Behavior of Silica Nanoparticles Synthesized from Rice Husk Ash by the Sol-Gel Method as a Photocatalytic and Antibacterial Agent

Materials (Basel). 2022 Nov 18;15(22):8211. doi: 10.3390/ma15228211.

Authors

A Alhadhrami¹, Gehad G Mohamed^{2

3}, Ahmed H Sadek^{4

5}, Sameh H Ismail⁴, A A Ebnalwaled⁶, Abdulraheem S A Almalki¹

Affiliations

¹ Department of Chemistry, College of Science, Taif University, P.O. Box 11099, Taif 21944, Saudi Arabia.
² Chemistry Department, Faculty of Science, Cairo University, Giza 12613, Egypt.
³ Nanoscience Department, Basic and Applied Sciences Institute, Egypt-Japan University of Science and Technology, Alexandria 21934, Egypt.
⁴ Faculty of Nanotechnology for Postgraduate Studies, Cairo University, Sheikh Zayed Campus, Giza 12588, Egypt.
⁵ Zewail City of Science, Technology and Innovation, Giza 12578, Egypt.
⁶ Electronics & Nano Devices (END) Lab, Physics Department, Faculty of Science, South Valley University, Qena 83523, Egypt.

Abstract

Silica nanoparticles (SiO₂ NPs) are one of the most well-studied inorganic nanoparticles for many applications. They offer the advantages of tunable size, biocompatibility, porous structure, and larger surface area. Thus, in this study, a high yield of SiO₂ NPs was produced via the chemical treatment of rice husk ash by the sol-gel method. Characteristics of the prepared SiO₂ NPs were validated using different characterization techniques. Accordingly, the phase, chemical composition, morphological, and spectroscopic properties of the prepared sample were studied. The average particle size of the SiO₂ NPs was found to be approximately 60-80 nm and the surface area was 78.52 m²/g. The prepared SiO₂ NPs were examined as photocatalysts for the degradation of methyl orange (MO) dye under UV irradiation. It was found that the intensity of the characteristic absorption band of MO decreased gradually with exposure time increasing, which means the successful photodegradation of MO by SiO₂ NPs. Moreover, the antibacterial activity of obtained SiO₂ NPs was investigated by counting the coliform bacteria in the surface water using the most probable number (MPN) index method. The results revealed that the MPN of coliform bacteria untreated and treated by SiO₂ NPs was estimated to be 170 CFU/100 mL and 10 CFU/100 mL, respectively, resulting in bacterial growth inhibition of 94.12%.

Keywords: antibacterial activity; photodegradation efficiency; rice husk ash; silica nanoparticles; sol–gel method.

Grants and funding

This research was funded by the Academy of Scientific Research and Technology (ASRT), Egypt, under a grant titled “full integration of rice husk and straw to produce nanosilica and nanocellulose for deepening local manufacture”.