Synthesis, characterization, photoluminescence, and antibacterial activities of silica-graphene oxide composites

Abstract

In this research, a novel thin film Si-GO10 and nano-powders Si-GO30 of silica-graphene oxide composite were prepared via sol-gel method and deposited on glass substrates using spray pyrolysis. XRD results showed a relatively strong peak in graphite layer that corresponds to the plane of (002). TEM images displayed that SiO<sub>2</sub> nano-particles were randomly distributed on the surface of Si-GO30 sample, and the particle size in these nano-powders was below 50 nm. Moreover, silica nano-particles on the surface of GO plates exhibited almost a spherical and rod-like nanoparticles shapes, which in turn confirmed the formation of SiO<sub>2</sub>-GO nano-hybrids. FESEM analysis reveals a different morphology, the Si-GO10 sample is so rough and crumble, while the Si-GO30 sample is relatively smooth on the surface. Photocatalytic investigations revealed the composite materials exhibit high activity for dye adsorption and decomposition. Si-GO10 thin film did not undergo degradation after 120 minutes, however, for Si-GO30 nano-powder, the adsorption peak intensity was reduced to 665 nm, indicating a decrease in the dye concentration in the solution. FTIR analysis demonstrated that carboxylic functional groups are decreased by increasing silica particles. Photo-Luminescence (PL) spectrum in Si-GO10 thin film disclosed a severe emission peak at about 675 nm. This spectrum was completely disappeared in Si-GO30 nano-powders. Results of the antibacterial properties emphasized that Si-GO30 nano-particle would prevent Escherichia. coli growth after 20 hours. The presented methodology allows for the synthesis of graphene oxide supported silicon dioxide nano-particles for promising applications in photocatalytic and antibacterial fields.

Graphene Based Membrane Modified Silica Nanoparticles for Seawater Desalination and Wastewater Treatment: Salt Rejection and Dyes

“…The results of the antimicrobial test of GO/SiO2 against Escherichia coli and Staphylococcus aureus with the disc diffusion method (Table 2 and Figure 6) showed that the inhibitory power of E. coli was stronger than S. aureus; The increase in GO-SiO2 (ppm) concentration further strengthens the antibacterial activity of the E. coli stable. Thus, the membrane material will be confirmed to have resistance to bacterial growth (E. coli and S. aureus) [36]. Bacterial-mediated infections can cause various acute or chronic diseases and antibiotic resistance in pathogenic bacteria has become a serious health problem.…”

“…The use of GO material in membrane preparation will provide biosafety advantages [22]. Likewise, the presence of SiO2 nanoparticles, also has excellent properties as an anti-bacterial material [36,37].…”