Preparation Of Graphene/Mesoporous Silica Nano Composites And Study Of Their Adsoption Performance

Graphen has been paid extensive attention because of their excellent properties, such as larger surface area, mechanically stronger, thermal conductivity. Moreover, graphene shows promising ability for photothermal application. Mesoporous silica also show attractive features, such as large surface areas, hydrophilic and tunable ordered pore sizes and volumes, making them ideal materials in many areas. Herein, two multifunctional mesoporous silica-GO (GO@mSiO2) and mesoporous silica-Fe3O4-GO (Fe3O4/GO@mSiO2) adsorbents were synthesized01. Preparation of sandwich-like mesoporous silica-coated graphene oxidation as adsorbent nanocomposites for removal of methylene blue from water (GO@mSiO2). The thickness of composites GO@mSiO2 is 9 nm. The surface area of G0@mSiO2 is 634 m2/g and the average pore size is 2.8 nm. GO@mSi02 shows promising ability for photothermal performance. The composites could be used in removal of methylene blue from water. In this paper, we mainly researched on the following aspects including pH of solution, concentration of methylene blue, different temperature and so on. The adsorption ability was superior when the optimum pH was 4. The maximum adsorption capacity for methylene blue was 305.3 mg·g-1 and the removal efficiency was 93%. The maximum adsorption capacity increased with concentration of methylene blue, while adsorption efficiency decreased. GO@mSiO2 has better recycle performance. A second-order kinetic equation could best describe the adsorption kinetics. Thermodynamic parameters indicated that the adsorption of methylene blue was thermodynamically feasible and could occur spontaneously.2. Preparation sandwich-like Fe3O4/GO@mSiO2 nanocomposite and study their adsoption properties to methylene blue. Magnetic graphene composites were prepared by solvothermal method. The thickness of composites Fe3O4/GO@mSiO2 is 15 nm. The surface area of Fe3O4/GO@mSiO2 is 179 m/g and the average pore size is 2.2 nm. It could be recycled by using the external magnetic field because of its magnetic property. When irradiated with 980 nm NIR laser, the Fe3O4/GO@mSiO2 exhibited better photo-thermal performance. Afterwards, we studied their adsoption properties to methylene blue.The results indicated that the adsoprion expressed best adsorption capacity when pH was 5. The maximum adsorption capacity for methylene blue was 125.1 mg·g-1 and the removal efficiency was 96%. The higher the temperature was, the lower removal efficiency was. A second-order kinetic equation could also best describe the adsorption kinetics. It was Langmuir monolayer adsorption. The adsorption of methylene blue could occur spontaneously.