Phosphate removal is crucial for eutrophication control and water quality improvement.Electro-assisted adsorption,an eco-friendly elec-trosorption process,exhibited a promising potential for wastewater treatment.Howev...Phosphate removal is crucial for eutrophication control and water quality improvement.Electro-assisted adsorption,an eco-friendly elec-trosorption process,exhibited a promising potential for wastewater treatment.However,there are few works focused on phosphate electro-sorption,and reported electrodes cannot attach satisfactory removal capacities and rates.Herein,electro-assisted adsorption of phosphate via in-situ construction of La active centers on hierarchically porous carbon(LaPC)has been originally demonstrated.The resulted LaPC composite not only possessed a hierarchically porous structure with uniformly dispersed La active sites,but also provided good conductivity for interfacial electron transfer.The LaPC electrode achieved an ultrahigh phosphate electrosorption capability of 462.01 mg g^(-1) at 1 V,outperforming most existing electrodes.The superior phosphate removal performance originates from abundant active centers formed by the coupling of electricfield and capture sites.Besides,the stability and selectivity toward phosphate capture were maintained well even under comprehensive conditions.Moreover,a series of kinetics and isotherms models were employed to validate the electrosorption process.This work demonstrates a deep understanding and promotes a new level of phosphate electrosorption.展开更多
Electrosorption technology was used to treat the reused comprehensive wastewater from iron and steel industry. A problem of relatively high conductivity of wastewater which greatly affects the reuse was examined, and ...Electrosorption technology was used to treat the reused comprehensive wastewater from iron and steel industry. A problem of relatively high conductivity of wastewater which greatly affects the reuse was examined, and industrial test was conducted for the reused water advanced deionization and purification in a comprehensive wastewater treatment plant o{ WISCO [Wuhan Iron and Steel （Group） Corporation]. The results of the on-site in- dustrial test showed a satisfactory treatment performance for the reused water even at a flow rate of 1 000 L/h in a standard 500 L/h unit. The average conductivity decreased by about 70%, from 580--780 μS/cm to 100--350 μS/cm. The average removal efficiency of CI and Ca2＋ was about 75% and 68%, respectively, and CODcr of the treated wa- ter was also reduced in some degree while the pH value was almost unchanged. The energy consumption was as low as 0.6 kWh/t, which was remarkably superior to the conventional technologies. Therefore, it is entirely feasible that the novel eleetrosorption technology can be used in enhanced desalination and purification treatment of reused com- prehensive wastewater in iron and steel industry.展开更多
Development of novel electrode materials with the integration of structural and compositional merits can essentially improve the electrosorption performance.Herein,we demonstrate a new strategy,named as carbothermal d...Development of novel electrode materials with the integration of structural and compositional merits can essentially improve the electrosorption performance.Herein,we demonstrate a new strategy,named as carbothermal diffusion reaction synthesis(CDRS),to fabricate binder-free CrN/carbon nanofiber electrodes for efficient electrosorption of fluoride ions from water.The CDRS strategy involves electrospinning MIL-101(Cr)particles with polyacrylonitrile(PAN)to form one-dimensional nanofiber,followed by spatial-confined pyrolysis process in which the nitridation reaction occurred between nitrogen element from PAN and chromium element from MIL-101(Cr),resulting macroscopic,free-standing electrodes with well dispersed ultrafine CrN nanoparticles on porous nitrogen enriched carbon matrix.As expected,the F-adsorption capacity reached 47.67 mg g-1 and there was no decrease in F-removal after 70 adsorption regenerations in 50 mg L-1 F-solution at 1.2 V.The adsorption mechanism of F-was explored by X-ray photoelectron spectroscopy(XPS)and density functional theory(DFT).The enhanced F-adsorption capacity was achieved by the reversible Cr4+/Cr3+redox pair provided by CrN and the electrical double layer capacitance produced by carbon skeleton.This study provides guidance on synergistic modulation of shaping and composition optimization of novel functional materials for electrosorption,catalysis,and supercapacitor applications.展开更多
This study focused on As(V)removal by electrosorption in a self-made three-dimensional electrode reactor,in which granular activated carbon(GAC)was used as the particle electrode.Under the optimal conditions,the remov...This study focused on As(V)removal by electrosorption in a self-made three-dimensional electrode reactor,in which granular activated carbon(GAC)was used as the particle electrode.Under the optimal conditions,the removal efficiency of As(V)was 84%,and its residual concentration in solution was 0.08 mg/L.From kinetic investigation,the rate determining steps of the entire process may involve more than two processes:membrane diffusion,material diffusion and physical/chemical adsorption processes.During the desorption process,As(V)can be desorbed from GAC,and the GAC was able to electro-adsorb As(V)again after desorption,which means that the electrode has good cycling performance.展开更多
The“battery type”inorganic electrode has been demonstrated the highly efficient sodium ion intercalation capacity for capacitive deionization.In this work,the CoMn_(2)O_(4)(CMO)microspheres with porous core-shell st...The“battery type”inorganic electrode has been demonstrated the highly efficient sodium ion intercalation capacity for capacitive deionization.In this work,the CoMn_(2)O_(4)(CMO)microspheres with porous core-shell structure are prepared via co-precipitation and followed by annealing.The effects of annealing temperatures on the morphology,pore structure,valence state,and electrochemical behavior of CMO are explored.As electrode for capacitive deionization,the salt removal capacity and current efficiency of optimized AC||CMO device reaches up to 60.7 mg g^(−1) and 97.6%,respectively,and the capacity retention rate is 74.1%after 50 cycles.Remarkably,both the in-situ X-ray diffraction and ex-situ X-ray diffraction analysis features that the intercalation/de-intercalation of sodium ions are governed by(103)and(221)crystal planes of CMO.Accordingly,the density functional theory calculations realize that the adsorption energies of Na+onto(103)and(221)crystal planes are higher than that of any other crystal planes,manifesting the priorities in adsorption of sodium atoms.Furthermore,the X-ray photoelectron spectra of pristine and post-CMO electrode highlights that the reversible conversion of Mn^(3+)/Mn^(4+)couple is resulted from the intercalation/de-intercalation of Na^(+),while this is irreversible for Co^(3+)/Co^(2+)couple.Beyond that,the CMO electrode has been proven the selectivity removal of Na^(+) over K^(+)and Mg^(2+)in a multi-cation stream.展开更多
Ce-TiO2/CA（carbon aerogel） electrode was prepared by sol impregnation approach. The XRD（X-ray diffraction） and Raman spectra reveal that the TiO2 is anatase. The UV-vis diffuse reflectance spectra show that the op...Ce-TiO2/CA（carbon aerogel） electrode was prepared by sol impregnation approach. The XRD（X-ray diffraction） and Raman spectra reveal that the TiO2 is anatase. The UV-vis diffuse reflectance spectra show that the optical absorption edge for Ce-TiO_2/CA is red-shifted to 535 nm compared with TiO_2/CA. Under visible light irradiation, the photocurrent density increment on Ce-TiO_2/CA is 75 times that on Ce-TiO_2/FTO（fluorine-doped tin oxide）. The electrochemical impedance spectroscopy reveals that the conductivity of CeTiO_2/CA is much better than the Ce-TiO_2/FTO. Furthermore, the Ce-TiO_2/CA can be used to the highest electrosorptive photodegradation for 4-chlorophenol wastewater degradation, which is ascribed predominantly to the efficient reduction of electron-hole pair recombination in the photocatalysts.展开更多
Electrosorption of oxygen and CO on Ru(0001) surface were investigated by ex-situ electron diffraction (LEED/RHEED), AES and electrochemical data. The Ru(0001) surface exhibited a strongly affinity for oxygen which g...Electrosorption of oxygen and CO on Ru(0001) surface were investigated by ex-situ electron diffraction (LEED/RHEED), AES and electrochemical data. The Ru(0001) surface exhibited a strongly affinity for oxygen which gave preference to form a (22)-O phase. However, anodization of Ru(0001) electrode produced a (11)-O phase. A coadsorption structure (2CO+O)(22) / Ru(0001) was performed from electrosorption of CO on Ru(0001) surface in electrolyte solution.展开更多
Extracting uranium from seawater offers opportunities for sustainable nuclear fuel supply,but the task is quite challenging due to the low uranium concentration(~3 ppb)in seawater.Here,based on the Knoevenagel condens...Extracting uranium from seawater offers opportunities for sustainable nuclear fuel supply,but the task is quite challenging due to the low uranium concentration(~3 ppb)in seawater.Here,based on the Knoevenagel condensation reaction of aldehyde and acetonitrile groups,a novel stable sp^(2)carbon-linked three-dimensional covalent organic framework(3D COF),TFPM-PDANAO was prepared as a porous platform for uranium extraction from seawater.The TFPM-PDAN-AO designed with regular 3D pore channel of 7.12 A provides a specific channel for uranyl diffusion,which exhibits high selectivity and fast kinetics for uranium adsorption.Meanwhile,the superior stability and optoelectronic properties enable it an excellent porous platform for uranium electroextraction.By applying alternating voltages between-5 and 0 V,uranyl ions can rapidly migrate and enrich into the porous structure of TFPM-PDAN-AO,then inducing the electrodeposition of uranium compounds to form the charge neutral species(Na_(2)O(UO_(3)H_(2)O)x)with an unprecedentedly high adsorption capacity of 4,685 mg g^(-1).This work not only expands the application prospects of functionalized 3D COFs,but also provides a technical support for the electrodeposition adsorption of uranium from seawater.展开更多
The adsorption kinetics for model pollutants on activated carbon fiber(ACF)by polarization was investigated in this work.Kinetics data obtained for the adsorption of these model pollutants at open-circuit,400 mV,and−4...The adsorption kinetics for model pollutants on activated carbon fiber(ACF)by polarization was investigated in this work.Kinetics data obtained for the adsorption of these model pollutants at open-circuit,400 mV,and−400 mV polarization were applied to the Lagergren equation,and adsorption rate constants(Ka)were determined.With the anodic polarization of 400 mV,the capacity of sodium phenoxide was increased from 0.0083 mmol/g at open-circuit to 0.18 mmol/g,and a 17-fold enhancement was achieved;however,the capacity of p-nitrophenol was decreased from 2.93 mmol/g at open-circuit to 2.65 mmol/g.With the cathodal polarization of−400 mV,the capacity of aniline was improved from 3.60 mmol/g at open-circuit to 3.88 mmol/g;however,the capacity of sodium dodecylben-zene sulfonate was reduced from 2.20 mmol/g at open-circuit to 1.59 mmol/g.The enhancement for electrosorption changed with dif ferent groups substituting.Anodic polarization enhances the adsorption of benzene with the electron-donating group.But whether anodic or not,cathodal polariza-tion had less effect on the adsorption of electron-accepting aromatic compounds,and decreased the adsorption capacity of benzene-bearing donor-conjugate bridge-acceptor,while increasing its adsorption rate.Electrostatic interaction played a very important role in the electrosorption of ion-pollutants.展开更多
Recovering valuable materials from waste streams is critical to the transition to a circular economy with reduced environmental damages caused by resource extraction activities.Municipal and industrial wastewaters con...Recovering valuable materials from waste streams is critical to the transition to a circular economy with reduced environmental damages caused by resource extraction activities.Municipal and industrial wastewaters contain a variety of materials,such as nutrients(nitrogen and phosphorus),lithium,and rare earth elements,which can be recovered as value-added products.Owing to their modularity,convenient operation and control,and the non-requirement of chemical dosage,electrochemical technologies offer a great promise for resource recovery in small-scale,decentralized systems.Here,we review three emerging electrochemical technologies for materials recovery applications:electrosorption based on carbonaceous and intercalation electrodes,electrochemical redox processes,and electrochemically induced precipitation.We highlight the mechanisms for achieving selective materials recovery in these processes.We also present an overview of the advantages and limitations of these technologies,as well as the key challenges that need to be overcome for their deployment in real-world systems to achieve cost-effective and sustainable materials recovery.展开更多
基金This work is financially supported by the National Science Foundation of Tianjin(17JCYBJC23300).
文摘Phosphate removal is crucial for eutrophication control and water quality improvement.Electro-assisted adsorption,an eco-friendly elec-trosorption process,exhibited a promising potential for wastewater treatment.However,there are few works focused on phosphate electro-sorption,and reported electrodes cannot attach satisfactory removal capacities and rates.Herein,electro-assisted adsorption of phosphate via in-situ construction of La active centers on hierarchically porous carbon(LaPC)has been originally demonstrated.The resulted LaPC composite not only possessed a hierarchically porous structure with uniformly dispersed La active sites,but also provided good conductivity for interfacial electron transfer.The LaPC electrode achieved an ultrahigh phosphate electrosorption capability of 462.01 mg g^(-1) at 1 V,outperforming most existing electrodes.The superior phosphate removal performance originates from abundant active centers formed by the coupling of electricfield and capture sites.Besides,the stability and selectivity toward phosphate capture were maintained well even under comprehensive conditions.Moreover,a series of kinetics and isotherms models were employed to validate the electrosorption process.This work demonstrates a deep understanding and promotes a new level of phosphate electrosorption.
基金Item Sponsored by Preferred Scientific Research Foundation for Returned Overseas Chinese Scholars,Ministry of Human Resources and Social Security of China([2007]170)
文摘Electrosorption technology was used to treat the reused comprehensive wastewater from iron and steel industry. A problem of relatively high conductivity of wastewater which greatly affects the reuse was examined, and industrial test was conducted for the reused water advanced deionization and purification in a comprehensive wastewater treatment plant o{ WISCO [Wuhan Iron and Steel （Group） Corporation]. The results of the on-site in- dustrial test showed a satisfactory treatment performance for the reused water even at a flow rate of 1 000 L/h in a standard 500 L/h unit. The average conductivity decreased by about 70%, from 580--780 μS/cm to 100--350 μS/cm. The average removal efficiency of CI and Ca2＋ was about 75% and 68%, respectively, and CODcr of the treated wa- ter was also reduced in some degree while the pH value was almost unchanged. The energy consumption was as low as 0.6 kWh/t, which was remarkably superior to the conventional technologies. Therefore, it is entirely feasible that the novel eleetrosorption technology can be used in enhanced desalination and purification treatment of reused com- prehensive wastewater in iron and steel industry.
基金financially supported by National Natural Science Foundation of China(Grant No.22276096).
文摘Development of novel electrode materials with the integration of structural and compositional merits can essentially improve the electrosorption performance.Herein,we demonstrate a new strategy,named as carbothermal diffusion reaction synthesis(CDRS),to fabricate binder-free CrN/carbon nanofiber electrodes for efficient electrosorption of fluoride ions from water.The CDRS strategy involves electrospinning MIL-101(Cr)particles with polyacrylonitrile(PAN)to form one-dimensional nanofiber,followed by spatial-confined pyrolysis process in which the nitridation reaction occurred between nitrogen element from PAN and chromium element from MIL-101(Cr),resulting macroscopic,free-standing electrodes with well dispersed ultrafine CrN nanoparticles on porous nitrogen enriched carbon matrix.As expected,the F-adsorption capacity reached 47.67 mg g-1 and there was no decrease in F-removal after 70 adsorption regenerations in 50 mg L-1 F-solution at 1.2 V.The adsorption mechanism of F-was explored by X-ray photoelectron spectroscopy(XPS)and density functional theory(DFT).The enhanced F-adsorption capacity was achieved by the reversible Cr4+/Cr3+redox pair provided by CrN and the electrical double layer capacitance produced by carbon skeleton.This study provides guidance on synergistic modulation of shaping and composition optimization of novel functional materials for electrosorption,catalysis,and supercapacitor applications.
基金financially supported by the National Natural Science Foundation of China (No. 52004256)the Shanxi Provincial Science Foundation for Youths, China (No. 201901D211212)+2 种基金the Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi Province, China (No. 2019L0574)the Young Academic Leader of North University of China (No. QX202004)the Postdoctoral Innovative Talent Support Program of Hunan Province, China (2021RC2010)
文摘This study focused on As(V)removal by electrosorption in a self-made three-dimensional electrode reactor,in which granular activated carbon(GAC)was used as the particle electrode.Under the optimal conditions,the removal efficiency of As(V)was 84%,and its residual concentration in solution was 0.08 mg/L.From kinetic investigation,the rate determining steps of the entire process may involve more than two processes:membrane diffusion,material diffusion and physical/chemical adsorption processes.During the desorption process,As(V)can be desorbed from GAC,and the GAC was able to electro-adsorb As(V)again after desorption,which means that the electrode has good cycling performance.
基金This work was supported by the National Natural Science Foundation of China (No.21862016)Project of Ningxia key R&D plan (No.2017BY064).
文摘The“battery type”inorganic electrode has been demonstrated the highly efficient sodium ion intercalation capacity for capacitive deionization.In this work,the CoMn_(2)O_(4)(CMO)microspheres with porous core-shell structure are prepared via co-precipitation and followed by annealing.The effects of annealing temperatures on the morphology,pore structure,valence state,and electrochemical behavior of CMO are explored.As electrode for capacitive deionization,the salt removal capacity and current efficiency of optimized AC||CMO device reaches up to 60.7 mg g^(−1) and 97.6%,respectively,and the capacity retention rate is 74.1%after 50 cycles.Remarkably,both the in-situ X-ray diffraction and ex-situ X-ray diffraction analysis features that the intercalation/de-intercalation of sodium ions are governed by(103)and(221)crystal planes of CMO.Accordingly,the density functional theory calculations realize that the adsorption energies of Na+onto(103)and(221)crystal planes are higher than that of any other crystal planes,manifesting the priorities in adsorption of sodium atoms.Furthermore,the X-ray photoelectron spectra of pristine and post-CMO electrode highlights that the reversible conversion of Mn^(3+)/Mn^(4+)couple is resulted from the intercalation/de-intercalation of Na^(+),while this is irreversible for Co^(3+)/Co^(2+)couple.Beyond that,the CMO electrode has been proven the selectivity removal of Na^(+) over K^(+)and Mg^(2+)in a multi-cation stream.
基金Project supported jointly by the Foundation of He'nan Educational Committee(15A150071)
文摘Ce-TiO2/CA（carbon aerogel） electrode was prepared by sol impregnation approach. The XRD（X-ray diffraction） and Raman spectra reveal that the TiO2 is anatase. The UV-vis diffuse reflectance spectra show that the optical absorption edge for Ce-TiO_2/CA is red-shifted to 535 nm compared with TiO_2/CA. Under visible light irradiation, the photocurrent density increment on Ce-TiO_2/CA is 75 times that on Ce-TiO_2/FTO（fluorine-doped tin oxide）. The electrochemical impedance spectroscopy reveals that the conductivity of CeTiO_2/CA is much better than the Ce-TiO_2/FTO. Furthermore, the Ce-TiO_2/CA can be used to the highest electrosorptive photodegradation for 4-chlorophenol wastewater degradation, which is ascribed predominantly to the efficient reduction of electron-hole pair recombination in the photocatalysts.
基金W.B.Wang is grateful for a fellowship from the Max-Planck-Gesellschaft(MPG). We also thank Prof. G. Ertl for helpful suggestions and discussions.
文摘Electrosorption of oxygen and CO on Ru(0001) surface were investigated by ex-situ electron diffraction (LEED/RHEED), AES and electrochemical data. The Ru(0001) surface exhibited a strongly affinity for oxygen which gave preference to form a (22)-O phase. However, anodization of Ru(0001) electrode produced a (11)-O phase. A coadsorption structure (2CO+O)(22) / Ru(0001) was performed from electrosorption of CO on Ru(0001) surface in electrolyte solution.
基金supported by the National Natural Science Foundation of China(22036003,21976077)the Natural Science Foundation of Jiangxi Province(20212ACB203009,20212ACB-203011)。
文摘Extracting uranium from seawater offers opportunities for sustainable nuclear fuel supply,but the task is quite challenging due to the low uranium concentration(~3 ppb)in seawater.Here,based on the Knoevenagel condensation reaction of aldehyde and acetonitrile groups,a novel stable sp^(2)carbon-linked three-dimensional covalent organic framework(3D COF),TFPM-PDANAO was prepared as a porous platform for uranium extraction from seawater.The TFPM-PDAN-AO designed with regular 3D pore channel of 7.12 A provides a specific channel for uranyl diffusion,which exhibits high selectivity and fast kinetics for uranium adsorption.Meanwhile,the superior stability and optoelectronic properties enable it an excellent porous platform for uranium electroextraction.By applying alternating voltages between-5 and 0 V,uranyl ions can rapidly migrate and enrich into the porous structure of TFPM-PDAN-AO,then inducing the electrodeposition of uranium compounds to form the charge neutral species(Na_(2)O(UO_(3)H_(2)O)x)with an unprecedentedly high adsorption capacity of 4,685 mg g^(-1).This work not only expands the application prospects of functionalized 3D COFs,but also provides a technical support for the electrodeposition adsorption of uranium from seawater.
基金This work was supported by the National Key Basic Research and Development(973)Program of China(Grant No.2003CB415006).
文摘The adsorption kinetics for model pollutants on activated carbon fiber(ACF)by polarization was investigated in this work.Kinetics data obtained for the adsorption of these model pollutants at open-circuit,400 mV,and−400 mV polarization were applied to the Lagergren equation,and adsorption rate constants(Ka)were determined.With the anodic polarization of 400 mV,the capacity of sodium phenoxide was increased from 0.0083 mmol/g at open-circuit to 0.18 mmol/g,and a 17-fold enhancement was achieved;however,the capacity of p-nitrophenol was decreased from 2.93 mmol/g at open-circuit to 2.65 mmol/g.With the cathodal polarization of−400 mV,the capacity of aniline was improved from 3.60 mmol/g at open-circuit to 3.88 mmol/g;however,the capacity of sodium dodecylben-zene sulfonate was reduced from 2.20 mmol/g at open-circuit to 1.59 mmol/g.The enhancement for electrosorption changed with dif ferent groups substituting.Anodic polarization enhances the adsorption of benzene with the electron-donating group.But whether anodic or not,cathodal polariza-tion had less effect on the adsorption of electron-accepting aromatic compounds,and decreased the adsorption capacity of benzene-bearing donor-conjugate bridge-acceptor,while increasing its adsorption rate.Electrostatic interaction played a very important role in the electrosorption of ion-pollutants.
基金We gratefully acknowledge the support from the startup fundsthe Cross-Disciplinary Research Fund from the George Washington University.
文摘Recovering valuable materials from waste streams is critical to the transition to a circular economy with reduced environmental damages caused by resource extraction activities.Municipal and industrial wastewaters contain a variety of materials,such as nutrients(nitrogen and phosphorus),lithium,and rare earth elements,which can be recovered as value-added products.Owing to their modularity,convenient operation and control,and the non-requirement of chemical dosage,electrochemical technologies offer a great promise for resource recovery in small-scale,decentralized systems.Here,we review three emerging electrochemical technologies for materials recovery applications:electrosorption based on carbonaceous and intercalation electrodes,electrochemical redox processes,and electrochemically induced precipitation.We highlight the mechanisms for achieving selective materials recovery in these processes.We also present an overview of the advantages and limitations of these technologies,as well as the key challenges that need to be overcome for their deployment in real-world systems to achieve cost-effective and sustainable materials recovery.
