Room-Temperature In-Situ Design and Use of Graphene Oxide-SBA-16 Composite for Water Remediation and Reusable Heterogeneous Catalysis

Abstract

In this paper, we report an in‐situ facile route to synthesize graphene oxide‐SBA‐16 (GO‐SBA‐16) composite in acidic medium at room temperature. Thermogravimetric analysis (TGA) exhibits excellent stability of the synthesised composite. X‐ray diffractograms (XRD), Fourier transformed infrared (FTIR) spectroscopy, and nitrogen sorption isotherms indicated the coexistence of GO and mesoporous silica particles in the composite. Moreover, field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) images gave clear evidence of the formation of GO‐SBA‐16 hybrid composite. Apart from this, the synthesised hybrid material shows not only highly proficient sorption capacities of toxic dyes but also excellent catalytic performance. The highly proficient sorption capacity of GO‐SBA‐16 towards toxic dyes (qm: 358.72 mg g−1 for Malachite Green, MG; qm: 536.63 mg g−1 for Methyl Violet, MV) can be explained on the basis of both hydrogen bonding and electrostatic interactions between the surface of GO‐SBA‐16 and dye molecules. Furthermore, GO‐SBA‐16 shows excellent catalytic efficiency towards metal free synthesis of amide from secondary amine and aromatic aldehyde. Finally, used GO‐SBA‐16 can be well regenerated and reused several times without causing any important decrement in the sorption efficacy and catalytic activity.

Mesoporous silica-based sensor for colorimetric determination of Basic Yellow 28 dye in aqueous solutions

“…The maximum achieved sorption capacity is 80 mg/g. The fast sorption time of other cationic dyes onto SBA-15 was reported previously, namely for the Basic Red 46 [26] (5 min), Basic Violet [27] (5 min) and Methylene Blue (10 min), whereas equilibrium time for sorption of anionic dyes was longer than in this study, for example for Reactive Red 2 and Safranin O was 30 min, and for Congo and Neutral Red 80 min [28]. The influence of the mass of sorbent was tested at initial concentration of the dye solution 20 mg/dm 3 and pH 8 in a period of 5 minutes, varying the sorbent mass in the range of 0.01 g to 0.2 g. Figure 2 displays the effect of the sorbent mass on the sorption capacity of BY28 dye onto SBA-15 mesoporous silicates.…”

“…Namely, sorption capacity varies from 67 (at pH 2) to 77 mg/g (at pH 8). It was reported in literature that sorption of cationic dyes onto SBA-15 rose with an increase of pH from 2 to 8 [26,29], while for the anionic dyes the opposite trend was detected [28]. The high sorption capacity of cationic dyes in alkaline environment was described by electrostatic and hydrogen bond interactions since SBA-15 is charged negative at high pH.…”

Adsorption performance of mesoporous silicas towards a cationic dye. Influence of mesostructure on adsorption capacity

“…In particular, mesoporous silica materials have been widely investigated as adsorbents for organic dyes due to their high surface area, large pore volume, structural stability, and tunable nanoscale mesostructures . The specific porous structure and the excellent textual properties allow easier diffusion of target molecules into the active sites .…”