Adsorption is one of the most effective technologies in the treatment of colored matter containing wastewater. Graphene related composites display potential to be an effective adsorbent. However, the adsorption mechan...Adsorption is one of the most effective technologies in the treatment of colored matter containing wastewater. Graphene related composites display potential to be an effective adsorbent. However, the adsorption mechanism and their regeneration approach are still demanding more efforts. An effective magnetically separable absorbent, Fe3O4 and reduced graphene oxide(RGO) composite has been prepared by an in situ coprecipitation and reduction method. According to the characterizations of TEM, XRD, XPS, Raman spectra and BET analyses, Fe3O4 nanoparticles in sizes of 10-20 nm are well dispersed over the RGO nanosheets, resulting in a highest specific area of 296.2 m2/g. The rhodamine B adsorption mechanism on the composites was investigated by the adsorption kinetics and isotherms. The isotherms are fitting better by Langmuir model, and the adsorption kinetic rates depend much on the chemical components of RGO. Compared to active carbon, the composite shows 3.7 times higher adsorption capacity and thirty times faster adsorption rates. Furthermore,with Fe3O4 nanoparticles as the in situ catalysts, the adsorption performance of composites can be restored by carrying out a Fenton-like reaction, which could be a promising regeneration way for the adsorbents in the organic pollutant removal of wastewater.展开更多
A series of graphene-TiO2 composites was fabricated from graphene oxide and titanium n-butoxide(TNB) by an ultrasonic-assisted method.The structure and composition of the nanocomposites were characterized by Raman spe...A series of graphene-TiO2 composites was fabricated from graphene oxide and titanium n-butoxide(TNB) by an ultrasonic-assisted method.The structure and composition of the nanocomposites were characterized by Raman spectroscopy,BET surface area measurements,X-ray diffraction,transmission electron microscopy,and ultraviolet-visible absorption spectroscopy.The average size of the TiO2 nanoparticles on the graphene nanosheets was controlled at around 10-15 nm without using surfactant,which is attributed to the pyrolysis and condensation of dissolved TNB into TiO2 by ultrasonic irradiation.The catalytic activity of the composites under ultrasonic irradiation was determined using a rhodamine B(RhB) solution.The graphene-TiO2 composites possessed a high specific surface area,which increased the decolorization rate for RhB solution.This is because the graphene and TiO2 nanoparticles in the composites interact strongly,which enhances the photoelectric conversion of TiO2 by reducing the recombination of photogenerated electron-hole pairs.展开更多
基金financially supported by National Natural Science Foundation of China (No. 21377084)Shanghai Municipal Natural Science Foundation (No. 13ZR1421000)
文摘Adsorption is one of the most effective technologies in the treatment of colored matter containing wastewater. Graphene related composites display potential to be an effective adsorbent. However, the adsorption mechanism and their regeneration approach are still demanding more efforts. An effective magnetically separable absorbent, Fe3O4 and reduced graphene oxide(RGO) composite has been prepared by an in situ coprecipitation and reduction method. According to the characterizations of TEM, XRD, XPS, Raman spectra and BET analyses, Fe3O4 nanoparticles in sizes of 10-20 nm are well dispersed over the RGO nanosheets, resulting in a highest specific area of 296.2 m2/g. The rhodamine B adsorption mechanism on the composites was investigated by the adsorption kinetics and isotherms. The isotherms are fitting better by Langmuir model, and the adsorption kinetic rates depend much on the chemical components of RGO. Compared to active carbon, the composite shows 3.7 times higher adsorption capacity and thirty times faster adsorption rates. Furthermore,with Fe3O4 nanoparticles as the in situ catalysts, the adsorption performance of composites can be restored by carrying out a Fenton-like reaction, which could be a promising regeneration way for the adsorbents in the organic pollutant removal of wastewater.
文摘A series of graphene-TiO2 composites was fabricated from graphene oxide and titanium n-butoxide(TNB) by an ultrasonic-assisted method.The structure and composition of the nanocomposites were characterized by Raman spectroscopy,BET surface area measurements,X-ray diffraction,transmission electron microscopy,and ultraviolet-visible absorption spectroscopy.The average size of the TiO2 nanoparticles on the graphene nanosheets was controlled at around 10-15 nm without using surfactant,which is attributed to the pyrolysis and condensation of dissolved TNB into TiO2 by ultrasonic irradiation.The catalytic activity of the composites under ultrasonic irradiation was determined using a rhodamine B(RhB) solution.The graphene-TiO2 composites possessed a high specific surface area,which increased the decolorization rate for RhB solution.This is because the graphene and TiO2 nanoparticles in the composites interact strongly,which enhances the photoelectric conversion of TiO2 by reducing the recombination of photogenerated electron-hole pairs.
