The magnetic composite-materials(Fe3O4@SDBS@LDHs)were prepared by sodium dodecyl benzene sulfonate(SDBS)modified layered double hydroxides(SDBS@LDHs)with Fe3O4via co-precipitation method.The results of XRD,FT-IR and S...The magnetic composite-materials(Fe3O4@SDBS@LDHs)were prepared by sodium dodecyl benzene sulfonate(SDBS)modified layered double hydroxides(SDBS@LDHs)with Fe3O4via co-precipitation method.The results of XRD,FT-IR and SEM/EDS indicated that the dispersibility of LDHs was improved,and the modification of SDBS took place on the surface of LDHs.The adsorption capacity of Fe3O4@SDBS@LDHs to brilliant green(BG)reaches329.1mg/g after the adsorption equilibrium.The thermodynamic parameters indicated that the adsorption process was endothermic and spontaneous,and the rate of a reaction increased with the raise of the reaction temperature.The Langmuir model was applicable for describing the sorption isotherms,indicating that the adsorption process is a monolayer adsorption.The results of kinetics study showed that adsorption fitted the pseudo-second order model well.The adsorbents still have good adsorption performance after four adsorption cycles.Moreover,the magnetic composite could be easily separated from aqueous solution.This indicated that Fe3O4@SDBS@LDHs can be considered as potential adsorbents in environmental applications for the removal of BG from aqueous solutions.展开更多
CdSe quantum dots(QDs)hybridized with graphene oxide(GO)are synthesized by a facile chemical precipitation method.The absorption of the CdSe/GO nanocomposite is increased with a significantblue shift with respect to C...CdSe quantum dots(QDs)hybridized with graphene oxide(GO)are synthesized by a facile chemical precipitation method.The absorption of the CdSe/GO nanocomposite is increased with a significantblue shift with respect to CdSe QDs.The specific surface area of the CdSe/GO nanocomposite is10.4m2/g,which is higher than that of CdSe QDs(5m2/g).The PL intensity of the CdSe/GO nanocomposite is lower than that of the CdSe QDs owing to the inhibition of the recombination of electron‐hole pairs in the composite.In Raman analysis,the two bands of the CdSe/GO nanocomposite are shifted to higher wavenumbers with respect to graphene oxide,which is attributed to electron injection that is induced by CdSe QDs into graphene oxide.Using the Brilliant Green dye,the photocatalytic reduction efficiency of CdSe QDs and the CdSe/GO nanocomposite under sunlight irradiation for90min are approximately81.9%and95.5%,respectively.The calculated photodegradation rate constants for CdSe QDs and the CdSe/GO nanocomposite are0.0190min–1and0.0345min–1,respectively.The enhanced photocatalytic activity of the CdSe/GO nanocomposite can be attributed to the high specific surface area and the reduction of electron‐hole pair recombination because of the introduction of graphene oxide.展开更多
The indirect electrochemical reduction of Indanthrene Brilliant Green FFB （IBG） was investigated in detail by cyclic voltammetry and electrolytic experiments.Triethanolamine （TEA） was used as ligand to form elec-t...The indirect electrochemical reduction of Indanthrene Brilliant Green FFB （IBG） was investigated in detail by cyclic voltammetry and electrolytic experiments.Triethanolamine （TEA） was used as ligand to form elec-trochemically active Fe（III）-complexes in alkaline solution.The effects of operating parameters including reaction temperature,current density,concentration of NaOH and Fe（III）-TEA mediator had been studied by orthogonal ex-periments and the mechanism of radicals on electrochemical reduction was discussed.The cyclic voltammetry ex-perimental results show that Fe（III）-TEA complexes are well suited for the indirect electrochemical reduction of IBG.The electrolytic experiments show that high current efficiency （49.9%） can be successfully achieved under op-timized conditions and the current density is found to be the main influence factor.展开更多
This paper investigated the analyses of removal of Methylene Blue (MB) and Brilliant Green (BG) dyes from aqueous solutions by adsorption on activated carbon prepared by chemical activation of coconut shell, eucalyptu...This paper investigated the analyses of removal of Methylene Blue (MB) and Brilliant Green (BG) dyes from aqueous solutions by adsorption on activated carbon prepared by chemical activation of coconut shell, eucalyptus tree, corn cob and flamboyant pod. It was found that the carbon pores increased after carbonization and activation processes. The maximum percentage MB removal was obtained as 95.0% for coconut shell, 93.2% for eucalyptus tree, 99.9% for corn cob, and 99.7% for flamboyant pod. Also, the maximum percentage BG removal was obtained as 97.0% for coconut shell, 98.2% for eucalyptus tree, 99.6% for corn cob, and 99.6% for flamboyant pod. The adsorption isotherms of the adsorption process were studied, and Freundlich model showed the best fit with the equilibrium data. To optimize the operating conditions, the effects of contact time, adsorbent dosage, and pH were investigated by two levels of factorial experimental design method and adsorbent dosage was found as the most significant factor.展开更多
基金Project(21476269)supported by the National Natural Science Foundation of China
文摘The magnetic composite-materials(Fe3O4@SDBS@LDHs)were prepared by sodium dodecyl benzene sulfonate(SDBS)modified layered double hydroxides(SDBS@LDHs)with Fe3O4via co-precipitation method.The results of XRD,FT-IR and SEM/EDS indicated that the dispersibility of LDHs was improved,and the modification of SDBS took place on the surface of LDHs.The adsorption capacity of Fe3O4@SDBS@LDHs to brilliant green(BG)reaches329.1mg/g after the adsorption equilibrium.The thermodynamic parameters indicated that the adsorption process was endothermic and spontaneous,and the rate of a reaction increased with the raise of the reaction temperature.The Langmuir model was applicable for describing the sorption isotherms,indicating that the adsorption process is a monolayer adsorption.The results of kinetics study showed that adsorption fitted the pseudo-second order model well.The adsorbents still have good adsorption performance after four adsorption cycles.Moreover,the magnetic composite could be easily separated from aqueous solution.This indicated that Fe3O4@SDBS@LDHs can be considered as potential adsorbents in environmental applications for the removal of BG from aqueous solutions.
基金supported by the National Natural Science Foundation of China(51774259)Engineering Research Center of Nano-Geo Materials of Ministry of Education(NGM2017KF004 and NGM2017KF012)~~
文摘CdSe quantum dots(QDs)hybridized with graphene oxide(GO)are synthesized by a facile chemical precipitation method.The absorption of the CdSe/GO nanocomposite is increased with a significantblue shift with respect to CdSe QDs.The specific surface area of the CdSe/GO nanocomposite is10.4m2/g,which is higher than that of CdSe QDs(5m2/g).The PL intensity of the CdSe/GO nanocomposite is lower than that of the CdSe QDs owing to the inhibition of the recombination of electron‐hole pairs in the composite.In Raman analysis,the two bands of the CdSe/GO nanocomposite are shifted to higher wavenumbers with respect to graphene oxide,which is attributed to electron injection that is induced by CdSe QDs into graphene oxide.Using the Brilliant Green dye,the photocatalytic reduction efficiency of CdSe QDs and the CdSe/GO nanocomposite under sunlight irradiation for90min are approximately81.9%and95.5%,respectively.The calculated photodegradation rate constants for CdSe QDs and the CdSe/GO nanocomposite are0.0190min–1and0.0345min–1,respectively.The enhanced photocatalytic activity of the CdSe/GO nanocomposite can be attributed to the high specific surface area and the reduction of electron‐hole pair recombination because of the introduction of graphene oxide.
基金Supported by the National Basic Research Program of China （2003CCA01300） the National Natural Science Foundation of China （20876151）
文摘The indirect electrochemical reduction of Indanthrene Brilliant Green FFB （IBG） was investigated in detail by cyclic voltammetry and electrolytic experiments.Triethanolamine （TEA） was used as ligand to form elec-trochemically active Fe（III）-complexes in alkaline solution.The effects of operating parameters including reaction temperature,current density,concentration of NaOH and Fe（III）-TEA mediator had been studied by orthogonal ex-periments and the mechanism of radicals on electrochemical reduction was discussed.The cyclic voltammetry ex-perimental results show that Fe（III）-TEA complexes are well suited for the indirect electrochemical reduction of IBG.The electrolytic experiments show that high current efficiency （49.9%） can be successfully achieved under op-timized conditions and the current density is found to be the main influence factor.
文摘This paper investigated the analyses of removal of Methylene Blue (MB) and Brilliant Green (BG) dyes from aqueous solutions by adsorption on activated carbon prepared by chemical activation of coconut shell, eucalyptus tree, corn cob and flamboyant pod. It was found that the carbon pores increased after carbonization and activation processes. The maximum percentage MB removal was obtained as 95.0% for coconut shell, 93.2% for eucalyptus tree, 99.9% for corn cob, and 99.7% for flamboyant pod. Also, the maximum percentage BG removal was obtained as 97.0% for coconut shell, 98.2% for eucalyptus tree, 99.6% for corn cob, and 99.6% for flamboyant pod. The adsorption isotherms of the adsorption process were studied, and Freundlich model showed the best fit with the equilibrium data. To optimize the operating conditions, the effects of contact time, adsorbent dosage, and pH were investigated by two levels of factorial experimental design method and adsorbent dosage was found as the most significant factor.
