The（CeO2/C）-β-PbO2-PTFE composite electrodes modified by graphite powder,cerium oxide powder,polytetrafluoroethylene（PTFE）and the homemade β-PbO2 powder were prepared by the high pressure molding technique.The X...The（CeO2/C）-β-PbO2-PTFE composite electrodes modified by graphite powder,cerium oxide powder,polytetrafluoroethylene（PTFE）and the homemade β-PbO2 powder were prepared by the high pressure molding technique.The X-ray diffraction（XRD）was used to test the purity of the homemade β-PbO2 powder.The surface structure and electrical property of electrodes were characterized by using scanning electron microscopy（SEM）and the cyclic voltammetry curves（CV）.Those images indicated that in electrolysis the（CeO2/C）-β-PbO2-PTFE composite electrodes had higher activity than the β-PbO2-PTFE electrodes,as good as the excellent catalytic performance.In the electrode system the composite electrodes were applied to treat reactive brilliant red（RBR）X-3B solution and we studied the degradation influence factors and the reaction mechanism.The results showed that the electrode system was well in treating RBR X-3B solution with the 20%（CeO2/C）-β-PbO2-PTFE composite electrodes at the initial 100 mg/L RBR X-3B concentration,Na2SO4 concentration of 0.35 mol/L,the constant current density of 30 mA/cm~!2 and electrolyte pH =2.After electrolytic time of 90 min,the maximum decolorization and chemical oxygen demand（COD）removal rates reached 88.92% and 54.54%.And the decolorization rate of RBR X-3B was in conformity with pseudo-first-order kinetics equation.The RBR X-3B degradation mechanism in the electrochemical oxidation system was used with LC-MS to analyze the possible intermediates and degradation pathway.展开更多
A novel polycyclodextrin-modified magnetic cationic hydrogel(PCD-MCH) was developed and its performance,kinetics and mechanism for the removal of reactive brilliant red X-3B(X-3B) were studied.The results showed that ...A novel polycyclodextrin-modified magnetic cationic hydrogel(PCD-MCH) was developed and its performance,kinetics and mechanism for the removal of reactive brilliant red X-3B(X-3B) were studied.The results showed that the zeta-potential of PCD-MCH was 32.8 to16.7 mV at pH 3.0-10.5.The maximum X-3B adsorption capacity of PCD-MCH was2792.3 mg/g.The adsorption kinetics could be well-described by the Weber-Morris model and the homogeneous surface diffusion model(HSDM).Diffusion stages corresponding to surface or film diffusion,intra-particle or wide mesopore diffusion,and narrow mesopore/micropore diffusion occurred at 0-120,120-480 and 480-1200 min,respectively.The latter two diffusion stages were rate-controlling for X-3B adsorption kinetics.At the initial X-3B concentration of 600 mg/L,the diffusion coefficient(Ds) and external mass transfer coefficient in the liquid phase(kF) were 3x10^-11 cm^2/min and 4.68 x 10^-6 cm/min,respectively.X-3B approaching the center of PCD-MCH particles could be observed at 360 min.At the end of the third diffusion stage,the Cp at q/qe=0 was 45.20 mg/L,which was close to the homogeneous Cp value of 46 mg/L along the radius of PCD-MCH particles.At pH 3.0-10.0,PCD-MCH showed stable X-3B adsorption capacities.After five regeneration-reuse cycles,the residual adsorption capacity of regenerated PCD-MCH was higher than 892.7 mg/g.The corresponding adsorption mechanism was identified as involving electrostatic interactions,cyclodextrin cavities and hydrogen bonds,of which cyclodextrin cavities showed prominent capture performance towards dye molecules through the formation of inclusion complexes.展开更多
基金Project supported by the Capacity Building Program of Shanghai Local Universities(12160503600)
文摘The（CeO2/C）-β-PbO2-PTFE composite electrodes modified by graphite powder,cerium oxide powder,polytetrafluoroethylene（PTFE）and the homemade β-PbO2 powder were prepared by the high pressure molding technique.The X-ray diffraction（XRD）was used to test the purity of the homemade β-PbO2 powder.The surface structure and electrical property of electrodes were characterized by using scanning electron microscopy（SEM）and the cyclic voltammetry curves（CV）.Those images indicated that in electrolysis the（CeO2/C）-β-PbO2-PTFE composite electrodes had higher activity than the β-PbO2-PTFE electrodes,as good as the excellent catalytic performance.In the electrode system the composite electrodes were applied to treat reactive brilliant red（RBR）X-3B solution and we studied the degradation influence factors and the reaction mechanism.The results showed that the electrode system was well in treating RBR X-3B solution with the 20%（CeO2/C）-β-PbO2-PTFE composite electrodes at the initial 100 mg/L RBR X-3B concentration,Na2SO4 concentration of 0.35 mol/L,the constant current density of 30 mA/cm~!2 and electrolyte pH =2.After electrolytic time of 90 min,the maximum decolorization and chemical oxygen demand（COD）removal rates reached 88.92% and 54.54%.And the decolorization rate of RBR X-3B was in conformity with pseudo-first-order kinetics equation.The RBR X-3B degradation mechanism in the electrochemical oxidation system was used with LC-MS to analyze the possible intermediates and degradation pathway.
基金supported by the National Key Research and Development Program of China (No.2017YFC0505303)the National Natural Science Foundation of China (Nos.51478041 and 51678053).
文摘A novel polycyclodextrin-modified magnetic cationic hydrogel(PCD-MCH) was developed and its performance,kinetics and mechanism for the removal of reactive brilliant red X-3B(X-3B) were studied.The results showed that the zeta-potential of PCD-MCH was 32.8 to16.7 mV at pH 3.0-10.5.The maximum X-3B adsorption capacity of PCD-MCH was2792.3 mg/g.The adsorption kinetics could be well-described by the Weber-Morris model and the homogeneous surface diffusion model(HSDM).Diffusion stages corresponding to surface or film diffusion,intra-particle or wide mesopore diffusion,and narrow mesopore/micropore diffusion occurred at 0-120,120-480 and 480-1200 min,respectively.The latter two diffusion stages were rate-controlling for X-3B adsorption kinetics.At the initial X-3B concentration of 600 mg/L,the diffusion coefficient(Ds) and external mass transfer coefficient in the liquid phase(kF) were 3x10^-11 cm^2/min and 4.68 x 10^-6 cm/min,respectively.X-3B approaching the center of PCD-MCH particles could be observed at 360 min.At the end of the third diffusion stage,the Cp at q/qe=0 was 45.20 mg/L,which was close to the homogeneous Cp value of 46 mg/L along the radius of PCD-MCH particles.At pH 3.0-10.0,PCD-MCH showed stable X-3B adsorption capacities.After five regeneration-reuse cycles,the residual adsorption capacity of regenerated PCD-MCH was higher than 892.7 mg/g.The corresponding adsorption mechanism was identified as involving electrostatic interactions,cyclodextrin cavities and hydrogen bonds,of which cyclodextrin cavities showed prominent capture performance towards dye molecules through the formation of inclusion complexes.
