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
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
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.
