Designing rational transition-metal/carbon composites with highly dispersed and firmly anchored nanoparticles(NPs)to prevent agglomeration and shedding is crucial for realizing excellent electrocatalytic performances....Designing rational transition-metal/carbon composites with highly dispersed and firmly anchored nanoparticles(NPs)to prevent agglomeration and shedding is crucial for realizing excellent electrocatalytic performances.Herein,a biomass pore-confined strategy based on mesoporous willow catkin is explored to obtain uniformly dispersed CoFe NPs in N-doped carbon nanotubes and hollow carbon fibers(CoFe@N-CNTs/HCFs).The resultant catalyst exhibits enhanced electrocatalytic performance,which affords a half-wave potential of 0.86 V(vs.RHE)with a limited current density of 6.0 mA·cm^(-2)for oxygen reduction reaction and potential of 1.67 V(vs.RHE)at 10 mA·cm^(-2)in 0.1 M KOH for oxygen evolution reaction.When applied to rechargeable zinc-air batteries,a maximum power density of 340 mW·cm^(-2)and long-term cyclic durability over 800 h are achieved.Such superior bifunctional electrocatalytic activities are ascribed to the biocarbon matrix with abundant mesopores and unobstructed hollow channels,CoFe NPs with high dispersion and controllable nanoscale and the hybrid composite with optimized electronic structure.This work presents an effective approach for constraining the size and dispersion of NPs in a low-cost biocarbon substrate,offering valuable insights for designing advanced oxygen electrocatalysts.展开更多
In this paper,biocarbon was prepared from corn husks as anode materials for potassium ion batteries at temperatures ranging from 700 to 1600℃.The prepared biocarbon materials have amorphous phase structure and posses...In this paper,biocarbon was prepared from corn husks as anode materials for potassium ion batteries at temperatures ranging from 700 to 1600℃.The prepared biocarbon materials have amorphous phase structure and possess larger interlayer spacing than graphite.The biocarbon exhibits enhanced graphitic degree and decreased amounts of surface defects,while the carbonization temperature gradually increases.The obtained potassium ion battery electrode at 1300℃ acquired high reversible capacity up to 216.6 mAh·g^(-1) at 0.1 A·g^(-1) after 100 cycles, and retained 128.6 mAh·g^(-1) at 1 A·g^(-1) even after500 cycles.The results indicate that the samples prepared at 1300℃ have better electrochemical performance than other samples prepared at different temperatures,which was attributed to the decisive influence of microstructure on surface-induced and intercalating potassium storage.展开更多
Biocarbonation of reactive magnesia based on microbially induced carbonate precipitation(MICP)process is a sustainable geotechnical reinforcement technology for strength development and permeability reduction.This met...Biocarbonation of reactive magnesia based on microbially induced carbonate precipitation(MICP)process is a sustainable geotechnical reinforcement technology for strength development and permeability reduction.This method can be used to produce microbial restoration mortar(MRM)for the application of stone cultural relics restoration.In this paper,the influence of particle size distribution on the strength and porosity of MRM was examined.By mixing fine and coarse sandstone powder in various proportions,nine different particle size distributions were obtained to investigate the restoration performance,including the unconfined compressive strength(UCS),porosity,and color difference.The results indicate that the well-graded particle size distribution can lead to the UCS improvement and porosity reduction of MRM.The findings also imply that adding fine sandstone powder to the coarse sandstone powder can provide extra bridging contacts within the soil matrix.These bridging contacts can be easily connected by the precipitated hydrated magnesium carbonates(HMCs)minerals,consequently resulting in more effective bonding and filling within the pore matrix.The microstructural images of MRM confirm the formation of HMCs,which exhibited a dense network structure,filling out the gap and bonding the sandstone powders.Furthermore,the microbial restoration mortar showed a high weather resistance to dry-wet cycles,acid rain,and salt attack,which is attributed to better stability and strength of HMCs than the original calcic cemented minerals in sandstone.展开更多
Solid sorbents with enhanced capacity and selectivity towards CO2 are crucial in the design of an efficient capture process.Among the possible alternatives,K2CO3-doped activated carbons have shown high CO2 capture cap...Solid sorbents with enhanced capacity and selectivity towards CO2 are crucial in the design of an efficient capture process.Among the possible alternatives,K2CO3-doped activated carbons have shown high CO2 capture capacity and rapid carbonation reaction rate.In this work,a sustainable and low-cost approach is developed with a biomass-based activated carbon or biocarbon as support.The CO2 capture performance in cyclic sorption–desorption operation and the sorption kinetics have been investigated under different scenarios in a purpose-built fixed-bed set-up.Independent of the H2O concentration in the flue gas,a constant relative humidity(~20%)in the K2CO3-doped biocarbon bed promoted the carbonation reaction and boosted the CO2 sorption capacity(1.92 mmol/g at 50℃ and 14 kPa partial pressure of CO2).Carbonation is slower than physical adsorption of CO2 but wise process design could tune the operation conditions and balance capture capacity and sorption kinetics.展开更多
Reliable data of antibiotic use and environmental discharge as veterinary medicine are essential to help countries raise awareness of the appropriate use, control, and correct water release. The first approach is to c...Reliable data of antibiotic use and environmental discharge as veterinary medicine are essential to help countries raise awareness of the appropriate use, control, and correct water release. The first approach is to change the regulatory framework based on consuming information, use policy, and discharge laws. The important research contribution is a novel water treatment process to treat, remove, and reduce antibiotic concentration in discharged water, mainly those used in the animal protein industry. The low particle biochar added during the titanium isopropoxide hydrolysis reduces the titanium dioxide (TiO<sub><span style="vertical-align:sub;">2</span></sub><span>) agglomerates and promotes the adsorption surface process. Such improved catalyst material enhances the solar decomposition efficiency to 93% from original oxytetracycline with better correspondence with the Elovich kinetics, intraparticle diffusion, R-P isotherm, and Langmuir-Hinshelwood model.</span>展开更多
A biocarbon after activation process showed the removal percentage of 92% of methylene blue in solution, the equilibrium parameter—RL value was in the interval from 0 to 1, with 46% of surface coverage degree. The Fr...A biocarbon after activation process showed the removal percentage of 92% of methylene blue in solution, the equilibrium parameter—RL value was in the interval from 0 to 1, with 46% of surface coverage degree. The Freundlich constant (n) was higher than 1 as an indication of the physical adsorption process. The Radlich-Peterson calculations obtained the higher R2 value which g constant near 1, a high similarity with Langmuir model. Temkin constant B1 was a positive indication of endothermic process. All calculations provided favorable results for the use of activated biocarbon for dye removing and possible for other organic substances.展开更多
In various biomedical fields,noninvasive medical procedures are favored over invasive techniques,as the latter require major incisions or surgeries that cause bleeding,pain,and tissue scarring.The increased use of non...In various biomedical fields,noninvasive medical procedures are favored over invasive techniques,as the latter require major incisions or surgeries that cause bleeding,pain,and tissue scarring.The increased use of noninvasive biomedical equipment has created a demand for effective energy storage devices that are sufficiently compact to be used as a power source,easy to commercialize,and bio-friendly.Herein,we report the facile synthesis of nickel molybdenum oxide nanoparticle-infused biocarbon microfibers(NiMoO NPs@BCMFs)as a novel energy storage material.The microfibers were derived from the bracket fungus Laetiporus sulphureus.In a three-electrode system,the NiMoO NPs@BCMFs/nickel foam(NF)electrode delivered an areal capacity of 113µAh cm^(-2)at 1.5 mA cm^(-2),with excellent cycling stability.Its capacity retention was 104%,even after 20,000 cycles.Bare BCMFs were also synthesized from the fungal biomass to fabricate a negative BCMFs/NF electrode.This,together with the positive NiMoO NPs@BCMFs/NF electrode,was used to construct a bio-friendly(hybrid-type)micro-supercapacitor(BMSC),which exhibited maximum energy and power density values of 56µWh cm^(-2)and 11,250µW cm^(-2),respectively.When tested for its ability to power biomedical electronics,the BMSC device successfully operated an electrical muscle stimulator,inducing potential signals into a volunteer in real-time application.展开更多
Lithium metal anode is one of the ideal anode materials for the next generation of high-energy-density battery systems.Unfortunately,the uneven nucleation of Li leads to dendrite growth and volume changes during cycli...Lithium metal anode is one of the ideal anode materials for the next generation of high-energy-density battery systems.Unfortunately,the uneven nucleation of Li leads to dendrite growth and volume changes during cycling,resulting in poor electrochemical performance and potential safety hazards,which hinder its practical application.In this work,a low-cost chicken-bonederived carbon material(CBC)with a biomimetic structure was designed and synthesized using a simple one-step carbonization method.Combining theoretical calculations and experimental results,the self-doped N and S heteroatoms in CBC are demonstrated to effectively reduce the binding energy with Li atoms and lower the nucleation overpotential.After uniform nucleation,the Li metal grows in a spherical shape without dendrites,which is related to the reduction of the local current density inside the biomimetic crosslinking structure of CBC.Benefiting from this favorable Li growth behavior,the Li@CBC electrode achieves ultra-low nucleation overpotential(15.5 mV at 0.1 mA cm^(−2))and superdense lithium deposition(zero volume expansion rate at a capacity of 2 mAh cm^(−2))without introducing additional lithiophilic sites.The CBC retains a high Coulombic efficiency of over 98%in 479 cycles(1 mA cm^(−2)and 1 mAh cm^(−2))when applied in a half-cell with Li,and shows an excellent rate and cycling performance when applied in a full cell with LiFePO4 as the cathode.展开更多
Lithium metal is a compelling choice as an anode material for high-energy-density batteries,attributed to its elevated theoretical specific energy and low redox potential.Nevertheless,challenges arise due to its susce...Lithium metal is a compelling choice as an anode material for high-energy-density batteries,attributed to its elevated theoretical specific energy and low redox potential.Nevertheless,challenges arise due to its susceptibility to high-volume changes and the tendency for dendritic development during cycling,leading to restricted cycle life and diminished Coulombic efficiency(CE).Here,we innovatively engineered a kind of porous biocarbon to serve as the framework for a lithium metal anode,which boasts a heightened specific surface area and uniformly dispersed ZnO active sites,directly derived from metasequoia cambium.The porous structure efficiently mitigates local current density and alleviates the volume expansion of lithium.Also,incorporating the ZnO lithiophilic site notably reduces the nucleation overpotential to a mere 16 mV,facilitating the deposition of lithium in a compact form.As a result,this innovative material ensures an impressive CE of 98.5%for lithium plating/stripping over 500 cycles,a remarkable cycle life exceeding 1200 h in a Li symmetrical cell,and more than 82%capacity retention ratio after an astonishing 690 cycles in full cells.In all,such a rationally designed Li composite anode effectively mitigates volume change,enhances lithophilicity,and reduces local current density,thereby inhibiting dendrite formation.The preparation of a highperformance lithium anode frame proves the feasibility of using biocarbon in a lithium anode frame.展开更多
This study proposed an improved bio-carbonation of reactive magnesia cement(RMC)method for dredged sludge stabilization using the urea pre-hydrolysis strategy.Based on unconfined compression strength(UCS),pickling-dra...This study proposed an improved bio-carbonation of reactive magnesia cement(RMC)method for dredged sludge stabilization using the urea pre-hydrolysis strategy.Based on unconfined compression strength(UCS),pickling-drainage,and scanning electron microscopy(SEM)tests,the effects of prehydrolysis duration(T),urease activity(UA)and curing age(CA)on the mechanical properties and microstructural characteristics of bio-carbonized samples were systematically investigated and analyzed.The results demonstrated that the proposed method could significantly enhance urea hydrolysis and RMC bio-carbonation to achieve efficient stabilization of dredged sludge with 80%high water content.A significant strength increment of up to about 1063.36 kPa was obtained for the bio-carbonized samples after just 7 d of curing,which was 2.64 times higher than that of the 28-day cured ordinary Portland cement-reinforced samples.Both elevated T and UA could notably increase urea utilization ratio and carbonate ion yield,but the resulting surge in supersaturation also affected the precipitation patterns of hydrated magnesia carbonates(HMCs),which weakened the cementation effect of HMCs on soil particles and further inhibited strength enhancement of bio-carbonized samples.The optimum formula was determined to be the case of T?24 h and UA?10 U/mL for dredged sludge stabilization.A 7-day CA was enough for bio-carbonized samples to obtain stable strength,albeit slightly affected by UA.The benefits of high efficiency and water stability presented the potential of this method in achieving dredged sludge stabilization and resource utilization.This investigation provides informative ideas and valuable insights on implementing advanced bio-geotechnical techniques to achieve efficient stabilization of soft soil,such as dredged sludge.展开更多
Nowadays,hierarchically macro-/meso-/microporous 3D carbon materials have been paid more attention due to their imaginative application potential in specific electrochemistry.Here,we report a dualtemplate strategy usi...Nowadays,hierarchically macro-/meso-/microporous 3D carbon materials have been paid more attention due to their imaginative application potential in specific electrochemistry.Here,we report a dualtemplate strategy using eutectic NaCl/ZnCl2 melt as airtight and swelling agent to obtain 3D mesoporous skeleton structured carbon from renewable lignin.The prepared lignin-derived biocarbon material(LN-3-1)has a high specific surface area(1289 m^2 g^-1),a large pore volume(2.80 cm^3 g^-1),and a well-connected and stable structure.LN-3-1 exhibits extremely high activity and stability in acidic medium for oxygen reduction reaction(ORR),superior to Pt/C catalyst and most non noble-metal catalysts reported in recent literatures.The prepared carbon material was used as a cathode catalyst to assemble a H2-O2 single fuel cell,and its excellent catalytic performance has been confirmed with the maximum power density of 779 mW cm^-2,which is one of the highest power densities among non-metallic catalysts so far.Density functional theory(DFT)calculations indicate that the synergy of chlorine and nitrogen reconciles the intermediate adsorption energies,leading to an appropriate theoretical ORR onset potential.We develop a cost-effective and highly efficient method to prepare biocarbon catalyst for ORR in proton-exchange membrane fuel cells.展开更多
基金financially supported by the Natural Science Foundation of Shandong Province(No.ZR2022ME218)the National Natural Science Foundation of China(Nos.52102260,52171211 and 52202243)China Postdoctoral Science Foundation(Nos.2022M711545 and 2022M711371)。
文摘Designing rational transition-metal/carbon composites with highly dispersed and firmly anchored nanoparticles(NPs)to prevent agglomeration and shedding is crucial for realizing excellent electrocatalytic performances.Herein,a biomass pore-confined strategy based on mesoporous willow catkin is explored to obtain uniformly dispersed CoFe NPs in N-doped carbon nanotubes and hollow carbon fibers(CoFe@N-CNTs/HCFs).The resultant catalyst exhibits enhanced electrocatalytic performance,which affords a half-wave potential of 0.86 V(vs.RHE)with a limited current density of 6.0 mA·cm^(-2)for oxygen reduction reaction and potential of 1.67 V(vs.RHE)at 10 mA·cm^(-2)in 0.1 M KOH for oxygen evolution reaction.When applied to rechargeable zinc-air batteries,a maximum power density of 340 mW·cm^(-2)and long-term cyclic durability over 800 h are achieved.Such superior bifunctional electrocatalytic activities are ascribed to the biocarbon matrix with abundant mesopores and unobstructed hollow channels,CoFe NPs with high dispersion and controllable nanoscale and the hybrid composite with optimized electronic structure.This work presents an effective approach for constraining the size and dispersion of NPs in a low-cost biocarbon substrate,offering valuable insights for designing advanced oxygen electrocatalysts.
基金financially supported by the National Natural Science Foundation of China (Nos.51674068,51874079 and 11775226)the Natural Science Foundation of Hebei Province (Nos.E2018501091 and E2020501001)+4 种基金the Science and Technology Project of Hebei Province (No.15271302D)the Training Foundation for Scientific Research of Talents Project,Hebei Province (No.A2016005004)the Natural Science Foundation of Liaoning Province (No.2019-MS-110)the Fundamental Research Funds for the Central Universities (Nos.N182306001,N172302001,N172304044 and N182304015)Qinhuangdao City University Student of Science and Technology Innovation and Entrepreneurship Project (Nos.PZB1810008T-46 and PZB1810008T-14)。
文摘In this paper,biocarbon was prepared from corn husks as anode materials for potassium ion batteries at temperatures ranging from 700 to 1600℃.The prepared biocarbon materials have amorphous phase structure and possess larger interlayer spacing than graphite.The biocarbon exhibits enhanced graphitic degree and decreased amounts of surface defects,while the carbonization temperature gradually increases.The obtained potassium ion battery electrode at 1300℃ acquired high reversible capacity up to 216.6 mAh·g^(-1) at 0.1 A·g^(-1) after 100 cycles, and retained 128.6 mAh·g^(-1) at 1 A·g^(-1) even after500 cycles.The results indicate that the samples prepared at 1300℃ have better electrochemical performance than other samples prepared at different temperatures,which was attributed to the decisive influence of microstructure on surface-induced and intercalating potassium storage.
基金supported by Chongqing Research Institute Performance Incentive and Guidance Project(Grant No.cstc2021jxjl00028)Entrepreneurship and Innovation Support for Overseas Student,Chongqing,China(Grant No.CX2022007)Chongqing Municipal Special Project for Technological Innovation and Development Application(Grant No.JG2021072).
文摘Biocarbonation of reactive magnesia based on microbially induced carbonate precipitation(MICP)process is a sustainable geotechnical reinforcement technology for strength development and permeability reduction.This method can be used to produce microbial restoration mortar(MRM)for the application of stone cultural relics restoration.In this paper,the influence of particle size distribution on the strength and porosity of MRM was examined.By mixing fine and coarse sandstone powder in various proportions,nine different particle size distributions were obtained to investigate the restoration performance,including the unconfined compressive strength(UCS),porosity,and color difference.The results indicate that the well-graded particle size distribution can lead to the UCS improvement and porosity reduction of MRM.The findings also imply that adding fine sandstone powder to the coarse sandstone powder can provide extra bridging contacts within the soil matrix.These bridging contacts can be easily connected by the precipitated hydrated magnesium carbonates(HMCs)minerals,consequently resulting in more effective bonding and filling within the pore matrix.The microstructural images of MRM confirm the formation of HMCs,which exhibited a dense network structure,filling out the gap and bonding the sandstone powders.Furthermore,the microbial restoration mortar showed a high weather resistance to dry-wet cycles,acid rain,and salt attack,which is attributed to better stability and strength of HMCs than the original calcic cemented minerals in sandstone.
文摘Solid sorbents with enhanced capacity and selectivity towards CO2 are crucial in the design of an efficient capture process.Among the possible alternatives,K2CO3-doped activated carbons have shown high CO2 capture capacity and rapid carbonation reaction rate.In this work,a sustainable and low-cost approach is developed with a biomass-based activated carbon or biocarbon as support.The CO2 capture performance in cyclic sorption–desorption operation and the sorption kinetics have been investigated under different scenarios in a purpose-built fixed-bed set-up.Independent of the H2O concentration in the flue gas,a constant relative humidity(~20%)in the K2CO3-doped biocarbon bed promoted the carbonation reaction and boosted the CO2 sorption capacity(1.92 mmol/g at 50℃ and 14 kPa partial pressure of CO2).Carbonation is slower than physical adsorption of CO2 but wise process design could tune the operation conditions and balance capture capacity and sorption kinetics.
文摘Reliable data of antibiotic use and environmental discharge as veterinary medicine are essential to help countries raise awareness of the appropriate use, control, and correct water release. The first approach is to change the regulatory framework based on consuming information, use policy, and discharge laws. The important research contribution is a novel water treatment process to treat, remove, and reduce antibiotic concentration in discharged water, mainly those used in the animal protein industry. The low particle biochar added during the titanium isopropoxide hydrolysis reduces the titanium dioxide (TiO<sub><span style="vertical-align:sub;">2</span></sub><span>) agglomerates and promotes the adsorption surface process. Such improved catalyst material enhances the solar decomposition efficiency to 93% from original oxytetracycline with better correspondence with the Elovich kinetics, intraparticle diffusion, R-P isotherm, and Langmuir-Hinshelwood model.</span>
文摘A biocarbon after activation process showed the removal percentage of 92% of methylene blue in solution, the equilibrium parameter—RL value was in the interval from 0 to 1, with 46% of surface coverage degree. The Freundlich constant (n) was higher than 1 as an indication of the physical adsorption process. The Radlich-Peterson calculations obtained the higher R2 value which g constant near 1, a high similarity with Langmuir model. Temkin constant B1 was a positive indication of endothermic process. All calculations provided favorable results for the use of activated biocarbon for dye removing and possible for other organic substances.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIP)(No.2018R1A6A1A03025708).
文摘In various biomedical fields,noninvasive medical procedures are favored over invasive techniques,as the latter require major incisions or surgeries that cause bleeding,pain,and tissue scarring.The increased use of noninvasive biomedical equipment has created a demand for effective energy storage devices that are sufficiently compact to be used as a power source,easy to commercialize,and bio-friendly.Herein,we report the facile synthesis of nickel molybdenum oxide nanoparticle-infused biocarbon microfibers(NiMoO NPs@BCMFs)as a novel energy storage material.The microfibers were derived from the bracket fungus Laetiporus sulphureus.In a three-electrode system,the NiMoO NPs@BCMFs/nickel foam(NF)electrode delivered an areal capacity of 113µAh cm^(-2)at 1.5 mA cm^(-2),with excellent cycling stability.Its capacity retention was 104%,even after 20,000 cycles.Bare BCMFs were also synthesized from the fungal biomass to fabricate a negative BCMFs/NF electrode.This,together with the positive NiMoO NPs@BCMFs/NF electrode,was used to construct a bio-friendly(hybrid-type)micro-supercapacitor(BMSC),which exhibited maximum energy and power density values of 56µWh cm^(-2)and 11,250µW cm^(-2),respectively.When tested for its ability to power biomedical electronics,the BMSC device successfully operated an electrical muscle stimulator,inducing potential signals into a volunteer in real-time application.
基金National Natural Science Foundation of China,Grant/Award Numbers:22179005,92372207。
文摘Lithium metal anode is one of the ideal anode materials for the next generation of high-energy-density battery systems.Unfortunately,the uneven nucleation of Li leads to dendrite growth and volume changes during cycling,resulting in poor electrochemical performance and potential safety hazards,which hinder its practical application.In this work,a low-cost chicken-bonederived carbon material(CBC)with a biomimetic structure was designed and synthesized using a simple one-step carbonization method.Combining theoretical calculations and experimental results,the self-doped N and S heteroatoms in CBC are demonstrated to effectively reduce the binding energy with Li atoms and lower the nucleation overpotential.After uniform nucleation,the Li metal grows in a spherical shape without dendrites,which is related to the reduction of the local current density inside the biomimetic crosslinking structure of CBC.Benefiting from this favorable Li growth behavior,the Li@CBC electrode achieves ultra-low nucleation overpotential(15.5 mV at 0.1 mA cm^(−2))and superdense lithium deposition(zero volume expansion rate at a capacity of 2 mAh cm^(−2))without introducing additional lithiophilic sites.The CBC retains a high Coulombic efficiency of over 98%in 479 cycles(1 mA cm^(−2)and 1 mAh cm^(−2))when applied in a half-cell with Li,and shows an excellent rate and cycling performance when applied in a full cell with LiFePO4 as the cathode.
基金supported by the National Natural Science Foundation of China(22179005,92372207)Fundamental Research Funds for the Central Universities(2022CX01017).
文摘Lithium metal is a compelling choice as an anode material for high-energy-density batteries,attributed to its elevated theoretical specific energy and low redox potential.Nevertheless,challenges arise due to its susceptibility to high-volume changes and the tendency for dendritic development during cycling,leading to restricted cycle life and diminished Coulombic efficiency(CE).Here,we innovatively engineered a kind of porous biocarbon to serve as the framework for a lithium metal anode,which boasts a heightened specific surface area and uniformly dispersed ZnO active sites,directly derived from metasequoia cambium.The porous structure efficiently mitigates local current density and alleviates the volume expansion of lithium.Also,incorporating the ZnO lithiophilic site notably reduces the nucleation overpotential to a mere 16 mV,facilitating the deposition of lithium in a compact form.As a result,this innovative material ensures an impressive CE of 98.5%for lithium plating/stripping over 500 cycles,a remarkable cycle life exceeding 1200 h in a Li symmetrical cell,and more than 82%capacity retention ratio after an astonishing 690 cycles in full cells.In all,such a rationally designed Li composite anode effectively mitigates volume change,enhances lithophilicity,and reduces local current density,thereby inhibiting dendrite formation.The preparation of a highperformance lithium anode frame proves the feasibility of using biocarbon in a lithium anode frame.
基金supported by the National Natural Science Foundation of China(Grant Nos.41925012 and 42230710)the Key Laboratory Cooperation Special Project of Western Cross Team of Western Light,CAS(Grant No.xbzg-zdsys-202107).
文摘This study proposed an improved bio-carbonation of reactive magnesia cement(RMC)method for dredged sludge stabilization using the urea pre-hydrolysis strategy.Based on unconfined compression strength(UCS),pickling-drainage,and scanning electron microscopy(SEM)tests,the effects of prehydrolysis duration(T),urease activity(UA)and curing age(CA)on the mechanical properties and microstructural characteristics of bio-carbonized samples were systematically investigated and analyzed.The results demonstrated that the proposed method could significantly enhance urea hydrolysis and RMC bio-carbonation to achieve efficient stabilization of dredged sludge with 80%high water content.A significant strength increment of up to about 1063.36 kPa was obtained for the bio-carbonized samples after just 7 d of curing,which was 2.64 times higher than that of the 28-day cured ordinary Portland cement-reinforced samples.Both elevated T and UA could notably increase urea utilization ratio and carbonate ion yield,but the resulting surge in supersaturation also affected the precipitation patterns of hydrated magnesia carbonates(HMCs),which weakened the cementation effect of HMCs on soil particles and further inhibited strength enhancement of bio-carbonized samples.The optimum formula was determined to be the case of T?24 h and UA?10 U/mL for dredged sludge stabilization.A 7-day CA was enough for bio-carbonized samples to obtain stable strength,albeit slightly affected by UA.The benefits of high efficiency and water stability presented the potential of this method in achieving dredged sludge stabilization and resource utilization.This investigation provides informative ideas and valuable insights on implementing advanced bio-geotechnical techniques to achieve efficient stabilization of soft soil,such as dredged sludge.
基金the financial support from the National Natural Science Foundation of China(No.21373091)the Science and Technology Project of Guangzhou City(No.201704030040).
文摘Nowadays,hierarchically macro-/meso-/microporous 3D carbon materials have been paid more attention due to their imaginative application potential in specific electrochemistry.Here,we report a dualtemplate strategy using eutectic NaCl/ZnCl2 melt as airtight and swelling agent to obtain 3D mesoporous skeleton structured carbon from renewable lignin.The prepared lignin-derived biocarbon material(LN-3-1)has a high specific surface area(1289 m^2 g^-1),a large pore volume(2.80 cm^3 g^-1),and a well-connected and stable structure.LN-3-1 exhibits extremely high activity and stability in acidic medium for oxygen reduction reaction(ORR),superior to Pt/C catalyst and most non noble-metal catalysts reported in recent literatures.The prepared carbon material was used as a cathode catalyst to assemble a H2-O2 single fuel cell,and its excellent catalytic performance has been confirmed with the maximum power density of 779 mW cm^-2,which is one of the highest power densities among non-metallic catalysts so far.Density functional theory(DFT)calculations indicate that the synergy of chlorine and nitrogen reconciles the intermediate adsorption energies,leading to an appropriate theoretical ORR onset potential.We develop a cost-effective and highly efficient method to prepare biocarbon catalyst for ORR in proton-exchange membrane fuel cells.
