Preparation of Graphene Oxide Decorated Fe₃O₄@SiO₂ Nanocomposites with Superior Adsorption Capacity and SERS Detection for Organic Dyes

Abstract

The fast detection and removal of organic dyes from contaminated water has become an urgent environmental issue due to their high toxicity, chemical stability, and low biodegradability. In this paper, we have developed graphene oxide decorated Fe3O4@SiO2(Fe3O4@SiO2-GO) as a novel adsorbent aiming at the rapid adsorption and trace analysis of organic dyes followed by surface enhanced Raman scattering (SERS). The structure and morphology of the nanocomposites were characterized by transmission electron microscopy (TEM), Fourier infrared spectrometry (FT-IR), X-ray diffraction (XRD), and vibrating sample magnetometer (VSM). The obtained nanocomposites were used to adsorb methylene blue (MB) in aqueous solution based onπ-πstacking interaction and electrostatic attraction between MB and GO, and the adsorption behaviors of MB were investigated. Moreover, the obtained nanocomposites with adsorbed dyes were separated from the solution and loaded with silver nanoparticles for SERS detection. These nanocomposites showed superior SERS sensitivity and the lowest detectable concentration was 1.0 × 10−7 M.

Magnetic rice husk ash 'cleanser' as efficient methylene blue adsorbent

“…2(a)) showed that only the MRHA has peaks at 602 and 1398 cm −1 which are related to the Fe-O bending and stretching vibration respectively [29,30]. Both for RHA and MRHA the peaks observed at 468, 798, 1103, 3145 cm −1 indicate the silica functional groups of C-Si-O, Si-H, Si-O-Si and -OH stretching respectively [29,31,32]. The N 2 adsorption-desorption isotherms of RHA and MRHA showed Type-IV isotherm with H3-type hysteresis (Fig.…”

“…MRHA has a higher surface area and mesopore volume (Table S1) compared to RHA possibly caused by the presence of ferrite nanoparticles which is known to have a large surface area and pore volume [36]. Primarily, the higher mesopore volume of MRHA could be due to ferrite particles growing uniformly along the silica framework creating more mesopores [37] and functionalized iron oxide also has reportedly high inherent mesopore volume [29,30,37].…”

“…But when contact time is > 7 min increase in q t is sluggish. Removal efficiency increases with time but as equilibrium adsorption approaches the change is no longer significant due to the saturation of active sites on the adsorb-ent surface [29,38]. To further elucidate the MRHA's adsorptive properties, non-linear Lagergren (Eq.…”

Magnetic SiO 2 @CoFe 2 O 4 nanoparticles decorated on graphene oxide as efficient adsorbents for the removal of anionic pollutants from water

“…The obtained SiO 2 @CoFe 2 O 4 nanocomposites were then functionalized with amino groups by adding APTES as a precursor material [39]. Herein, 0.5 g of SiO 2 @CoFe 2 O 4 nanocomposites were added to the 50 mL of toluene, followed by adding 4 mL of APTES.…”

Characterization of Fe3O4/rGO Composites from Natural Sources: Application for Dyes Color Degradation in Aqueous Solution

“…For its good electrochemical performance, it is useful in energy storage applications [22] such as in lithium-ion batteries [23]. Fe3O4/rGO nanocomposites can be used as photocatalytic material [24,25], for reducing heavy metals such as Cu +2 , Zn +2 , Ni +2 ions [26], Cr -2 [27][28][29][30], Pb 2+ [27,30], detecting Cd +2 [31] ions, degradation of phenol, as an antibacterial [25], for biosensing [31], and as an absorbent for removing dyes in aqueous solutions [32][33][34]. It has the potential to be used in a sensor to detect the presence of arsenic in mineral water [35,36], and wastewater treatment [37].…”