Rational tuning of crystallographic surface and metal doping were effective to enhance the catalytic performance of metal organic frameworks,but limited work has been explored for achieving modulation of crystal facet...Rational tuning of crystallographic surface and metal doping were effective to enhance the catalytic performance of metal organic frameworks,but limited work has been explored for achieving modulation of crystal facets and metal doping in a single system.MIL-68(In)was promising for photocatalytic applications due to its low toxicity and excellent photoresponsivity.However,its catalytic activity was constrained by severe carrier recombination and a lack of active sites.Herein,increased(001)facet ratio and active sites exposure were simultaneously realized by cobalt doping in MIL-68(In)through a one-pot solvothermal strategy.Optimized MIL-68(In/Co)-2.5 exhibited remarkable catalytic performance in comparison with pristine MIL-68(In)and other MIL-68(In/Co).The reaction kinetic constant and degradation efficiency of MIL-68(In/Co)were approximately twice and 17%higher than the pristine MIL-68(In)in 36 min reaction,respectively.Density functional theory calculations revealed that Co dopant could modulate the orientation of MIL-68(In)facets,facilitate the exchange of electrons and reduce the adsorption energy of peroxymonosulfate(PMS).This work provides a novel pathway for improvement of In-based MOFs in PMS/vis system,it also promotes the profound comprehension of the correlation between crystal facet regulation and catalytic activation in the PMS/vis system.展开更多
Triclosan(TCS) poses harmful risks to ecosystems and human health owing to its endocrine-disrupting effects.Therefore,developing an efficient and sustainable technology to degrade TCS is urgently needed.Herein,cobalt ...Triclosan(TCS) poses harmful risks to ecosystems and human health owing to its endocrine-disrupting effects.Therefore,developing an efficient and sustainable technology to degrade TCS is urgently needed.Herein,cobalt oxyhydroxide @covalent organic frameworks(CoOOH@COFs) S-scheme heterojunction was synthesized,which combined the visible-light-driven photocatalysis and peroxymonosulfate(PMS) activation to synergistically generate abundant reactive oxygen species(ROSs) for TCS degradation.The degradation efficiency of TCS reached 100 % within 8 min in the Vis-CoOOH@COFs/PMS system,and the reaction rate constant was 0.456 min^(-1),which was nearly 1.90 and 2.85 times that of single Co OOH and COFs,and2.36 times that under dark condition,respectively.The density functional theory(DFT) calculations confirmed the energy band bending of CoOOH@COFs and S-scheme charge transport from COFs to Co OOH.Both experimental and theoretical analyses indicated that Co OOH@COFs in photocatalytic-PMS activation systems synergistically facilitated photo-generated carrier separation,enhanced interfacial electron transfer,accelerated PMS activation,and generated multiple ROSs.In particular,photogenerated electrons(e^(-))accelerated the Co(Ⅲ)/Co(Ⅱ) redox cycle,while the PMS captured the e-,which significantly decreased the charge combination of Co OOH@COFs.Radicals(O_(2)^(·-),^(·)OH,and SO_(4)^(·-)) and non-radicals(such as ^(1)O_(2),h^(+),and e^(-)) were both presented in the Vis-CoOOH@COFs/PMS system,with O_(2)^(-) playing a dominant role in TCS degradation.Furthermore,the pathway of TCS degradation and toxicity of intermediates were explored by DFT calculation and transformation product identification.Importantly,the environmentally friendly CoOOH@COFs S-scheme heterojunction exhibited excellent stability and reusability.In conclusion,this study innovatively designed an S-scheme heterojunction in the photocatalytic-PMS activation system,providing guidance and theoretical support for efficient and eco-friendly wastewater treatment.展开更多
The extensive use of tetracycline hydrochloride(TCH)poses a threat to human health and the aquatic environment.Here,magnetic p-n Bi2WO6/CuFe2O4 catalyst was fabricated to efficiently remove TCH.The obtained Bi2WO6/CuF...The extensive use of tetracycline hydrochloride(TCH)poses a threat to human health and the aquatic environment.Here,magnetic p-n Bi2WO6/CuFe2O4 catalyst was fabricated to efficiently remove TCH.The obtained Bi2WO6/CuFe2O4 exhibited 92.1%TCH degradation efficiency and 50.7%and 35.1%mineralization performance for TCH and raw secondary effluent from a wastewater treatment plant in a photo-Fenton-like system,respectively.The remarkable performance was attributed to the fact that photogenerated electrons accelerated the Fe(III)/Fe(II)and Cu(II)/Cu(I)conversion for the Fenton-like reaction between Fe(II)/Cu(I)and H2O2,thereby generating abundant·OH for pollutant oxidation.Various environmental factors including H2O2 concentration,initial pH,catalyst dosage,TCH concentration and inorganic ions were explored.The reactive oxidation species(ROS)quenching results and electron spin resonance(ESR)spectra confirmed that·O2-and·OH were responsible for the dark and photo-Fenton-like systems,respectively.The degradation mechanisms and pathways of TCH were proposed,and the toxicity of products was evaluated.This work contributes a highly efficient and environmentally friendly catalyst and provides a clear mechanistic explanation for the removal of antibiotic pollutants in environmental remediation.展开更多
The Roosevelt Hot Springs Known Geothermal Resource Area(KGRA) is a Basin and Range-type geothermal resource, which is located in southwestern Utah. The integrated multicomponent geothermometry(IMG) approach is used t...The Roosevelt Hot Springs Known Geothermal Resource Area(KGRA) is a Basin and Range-type geothermal resource, which is located in southwestern Utah. The integrated multicomponent geothermometry(IMG) approach is used to estimate the reservoir temperature at the Roosevelt Hot Springs KGRA. Geothermometric modeling results indicate the deep reservoir temperature is approximately 284.6°C. A conceptual model of the Roosevelt Hot Spring KGRA is provided through integrating the various pieces of exploration information, including the geological data, geothermometric results, temperature well log and field evidence. A two-dimensional cross-sectional model was thus built to quantitatively investigate the coupled thermal-hydraulic processes in the Roosevelt geothermal field. By matching the preproduction temperature log data of deep wells, parameters controlling flow and heat transport are identified. The method and model presented here may be useful for other geothermal fields with similar conditions.展开更多
As an antibiotic,sulfadiazine has posed a serious threat to humans and ecosystems due to its chronic toxicity.The advanced oxidation processes (AOPs) via heterogeneous catalytic activation of peroxymonosulfate (PMS) h...As an antibiotic,sulfadiazine has posed a serious threat to humans and ecosystems due to its chronic toxicity.The advanced oxidation processes (AOPs) via heterogeneous catalytic activation of peroxymonosulfate (PMS) have significant potential for the degradation of antibiotics.However,there are multiple restrictions including non-specifically binding to target contaminants,which would deplete oxidation capacity,and lacking energy effectiveness due to inefficient utilization of reactive oxygen species (ROS).To overcome these obstacles,we adopted the“bait-hook&destroy”strategy in this study.Herein,we synthesized a novel micrometer-sized Ni OOH hierarchical spheres assembled from nanosheets,which have relatively large specific surface areas and yield specified cavities to“bait-hook”sulfadiazine and PMS onto the surface cavities.This process was further conductive to effective generation of ROS and subsequently“destruction”of sulfadiazine with elevated mass transformation rate.20.4%of sulfadiazine can adsorb to Ni OOH surface in less than 30 min (0.0051 min^(-1)),and then sulfadiazine was completely degraded in 90min intervals in the Ni OOH/PMS system.The degradation rate constant (k=0.0537 min^(-1)) was about5.3,2.5 and 2.2 times higher than that in Ni_(2)O_(3)/PMS,NiO/PMS and Ni(OH)_(2)/PMS system,respectively.This was ascribed to the synergistic catalytic oxidation and adsorption process occurred on the surface of Ni OOH.Appreciably,there were both non-radicals (^(1)O_(2)) and radicals (O_(2)^(·-)and SO_(4)^(·-)) involved in the Ni OOH/PMS system,and^(1)O_(2)was distinguished as the dominated ROS for degradation of sulfadiazine.This study provides a novel strategy via synergistic adsorption and catalytic oxidation,and indicates that the micrometer-sized Ni OOH hierarchical sphere as heterogeneous catalyst is an attractive candidate for potential application of the SR-AOPs technology in water treatment.展开更多
Covalent organic frameworks(COFs)have attracted attention as photocatalysts,however,low electron transfer and reactive oxygen species(ROS)generation still hinder their photocatalytic application.In this work,we constr...Covalent organic frameworks(COFs)have attracted attention as photocatalysts,however,low electron transfer and reactive oxygen species(ROS)generation still hinder their photocatalytic application.In this work,we construct multivariate donor-acceptor(D-A)heterojunctions in the covalent organic frameworks by synchronously introducing electron-withdrawing and donating substituents.Importantly,the optoelectronic characteristics and visible-light photocatalytic performance were improved with the increase of the electron donor carbon chains in multivariate D-A COFs.Combining in‐situ characterization with theoretical calculations,the charge carrier separation and transfer efficiency,•O_(2)–generation and conversion,and the energy barrier of the rate determination steps related to the formation of*OH and*OOH,can be well regulated by the multivariate D-A COFs.More importantly,the ortho-carbon atom of the Br and OCH_(3) group-linked benzene rings and the imine bond(–C=N–)in COF-Br@OCH_(3) were activated to produce the key*OH and*OOH intermediates for effectively reducing the energy barrier of H2O oxidation and O_(2) reduction.This work provides valuable insights into the precise design and synthesis of COFs-based catalysts and the regulation of electron transfer and ROS generation by modulating the electron-withdrawing and donating substituents for highly efficient visible-light photocatalytic degradation of refractory organic pollutants.展开更多
Enhanced geothermal system(EGS) is an effective method for developing and utilizing hot dry rock(HDR). The key to the effectiveness of EGS is the construction of an artificial fracture network. The permeability of fra...Enhanced geothermal system(EGS) is an effective method for developing and utilizing hot dry rock(HDR). The key to the effectiveness of EGS is the construction of an artificial fracture network. The permeability of fractures has severe effects on the heat transfer efficiency and sustainability of geothermal energy. However, the evolution characteristics of hydraulic conductivity under different failure modes have not been adequately studied for HDR. To clarify this, rocks with different failure modes were investigated by conducting thermal triaxial compression experiments, and the fluid seepage related to different rock failure modes was comprehensively investigated. The results showed that the characteristic stresses and crack surface roughness of the rock increased as the confining pressure increased. The permeability in the composited failure mode was the largest(11.4 μm;), followed by that in the Y-shaped shear failure mode(9.7 μm;), and that in the single-shear failure mode was the smallest(7.2 μm;). The confining pressures had an inhibitory effect on permeability. As the confining pressure increased from 5 to 30 MPa, the permeability decreased by 88.8%, 88.4%, and 89.9%, respectively. In contrast, the permeability was significantly enhanced by 128.3%, 94.6%, and 131% as the flow rate increased from 3 to 7 m L/min.展开更多
The Z-scheme heterostructure for photocatalyst can effectively prolong the lifetime of photogenerated carriers and retain a higher conduction/valence band position,promoting the synergistic coupling of photocatalysis ...The Z-scheme heterostructure for photocatalyst can effectively prolong the lifetime of photogenerated carriers and retain a higher conduction/valence band position,promoting the synergistic coupling of photocatalysis and peroxymonosulfate(PMS) activation.In order to fully utilize the luminous energy and realize the efficient activation of PMS,this work achieved successful construction of NiCo_(2)O_(4)/BiOCl/Bi_(24)O_(31)Br_(10) ternary Z-scheme heterojunction by simultaneously synthesizing BiOCl and NiCo_(2)O_(4) with NiCl_(2) and CoCl_(2) as the precursors.The intercalated BiOCl could serve as a carrier migration ladder to further achieve the spatial separation of electron-hole pairs,so that the oxidation and reduction processes separately occurred in different regions.Compared with the reported catalysts,the as-prepared composites exhibited the enhanced removal efficiency for tetracycline hydrochloride(TCH) in the visible light/PMS system,with a degradation efficiency of 85.30%in 2 min,and possessed good stability.Z-scheme heterojunction was shown to be beneficial for maximizing the superiority of photo-assisted Fenton-like reaction system.The experimental and characterization results confirmed that both non-radicals(^(1)O_(2)) and radicals(SO_(5)^(·-) and SO_(4)^(·-)) were involved in the reaction process and the SO_(5)^(·-)generated by the oxidation of PMS played a crucial role in the TCH degradation.The possible reaction mechanism was finally proposed.This study provided new insight into the Z-scheme heterostructure to promote the photo-assisted Fenton-like reaction.展开更多
In this study,sodium tripolyphosphate(STPP)was used to promote the removal of organic pollutants in a zero-valent copper(ZVC)/O2 system under neutral conditions for the first time.20 mg/L p-nitrophenol(PNP)can be comp...In this study,sodium tripolyphosphate(STPP)was used to promote the removal of organic pollutants in a zero-valent copper(ZVC)/O2 system under neutral conditions for the first time.20 mg/L p-nitrophenol(PNP)can be completely decomposed within 120 min in the ZVC/O2/STPP system.The PNP degradation process followed pseudo-first-order kinetics and the degradation rate of PNP gradually increased upon the decreasing ZVC particle size.The optimal pH of the reaction system was 5.0.Our mechanism investigation showed that Cu+generated by ZVC corrosion was the main reducing agent for the activation of 02 to produce ROS.-OH was identified as the only ROS formed during the degradation of PNP and its production pathway was the double-electron activation of O2(O2→H2 O2→·OH).In this process,STPP did not only promote the release of Cu+through its complexation,but also promoted the production of OH by reducing the redox potential of Cu2+/Cu+.In addition,we could initiate and terminate the reaction by controlling the pH.At pH<8.1,ZVC/02/STPP could continuously degrade organic pollutants;at pH>8.1,the reaction was terminated.STPP was recycled to continuously promote the corrosion of ZVC and O2 activation as long as the pH was<8.1.This study provided a new and efficient way for O2 activation and organic contaminants removal.展开更多
As an important source of low-carbon,clean fossil energy,natural gas hydrate plays an important role in improving the global energy consumption structure.Developing the hydrate industry in the South China Sea is impor...As an important source of low-carbon,clean fossil energy,natural gas hydrate plays an important role in improving the global energy consumption structure.Developing the hydrate industry in the South China Sea is important to achieving‘carbon peak and carbon neutrality’goals as soon as possible.Deep-water areas subjected to the action of long-term stress and tectonic movement have developed complex and volatile terrains,and as such,the morphologies of hydrate-bearing sediments(HBSs)fluctuate correspondingly.The key to numerically simulating HBS morphologies is the establishment of the conceptual model,which represents the objective and real description of the actual geological body.However,current numerical simulation models have characterized HBSs into horizontal strata without considering the fluctuation characteristics.Simply representing the HBS as a horizontal element reduces simulation accuracy.Therefore,the commonly used horizontal HBS model and a model considering the HBS’s fluctuation characteristics with the data of the SH2 site in the Shenhu Sea area were first constructed in this paper.Then,their production behaviors were compared,and the huge impact of the fluctuation characteristics on HBS production was determined.On this basis,the key parameters affecting the depressurization production of the fluctuating HBSs were studied and optimized.The research results show that the fluctuation characteristics have an obvious influence on the hydrate production of HBSs by affecting their temperatures and pressure distributions,as well as the transmission of the pressure drop and methane gas discharge.Furthermore,the results show that the gas productivity of fluctuating HBSs was about 5%less than that of horizontal HBSs.By optimizing the depressurization amplitude,well length,and layout location of vertical wells,the productivity of fluctuating HBSs increased by about 56.6%.展开更多
Natural gas hydrate production involves complex mass/heat transfer,phase transformation,and multiphase seepage processes,where permeability critically influences exploitation efficiency and sediment stability.This rev...Natural gas hydrate production involves complex mass/heat transfer,phase transformation,and multiphase seepage processes,where permeability critically influences exploitation efficiency and sediment stability.This review summarizes progress in permeability evolution in hydrate-bearing sediments,covering:multiphase seepage theories involving absolute and relative permeability models;pore-scale methods,including Lattice Boltzmann,Pore Network models,CFD simulations,and microfluidic experiments,for investigating the effects of hydrate morphology and pore heterogeneity;core-scale experiments,such as seepage tests and X-ray CT,for quantifying permeability changes with hydrate saturation and stress sensitivity;site-scale scenarios involving pilot tests and numerical models are challenged by fluid migration prediction and reservoir stability.Key findings show hydrate dissociation induces dynamic pore structure changes and complex multiphase interactions,with existing models oversimplifying heterogeneous pore structures and hydrate distributions.Critical research gaps include:inadequate characterization of pore structure evolution during hydrate nucleation/dissociation;unclear gas-water flow mechanisms in deformable sediments;lack of multiscale correlation and coupled modeling for permeability-stress-phase change interactions.Addressing these offers critical insights for optimizing extraction,reducing energy use,and ensuring reservoir stability,enabling safe and efficient exploitation of natural gas hydrates as a strategic clean energy resource.展开更多
Waterborne viruses have caused outbreaks of related diseases and threaten human health,and advanced oxidation processes(AOPs),as clean and efficient technologies,have received widespread attention for their excellent ...Waterborne viruses have caused outbreaks of related diseases and threaten human health,and advanced oxidation processes(AOPs),as clean and efficient technologies,have received widespread attention for their excellent performance in inactivating viruses.However,heterogeneity in susceptibility of structurally distinct viruses to various reactive oxygen species(ROS)is unclear.This study first measured the heterogeneity in inactivation kinetics and biological mechanisms of four typical viral surrogates(MS2,phi6,phix174,and T4)to various ROS by visible light catalysis.Notably,the second-order inactivation rate constants of four viruses by hydroxyl radicals(·OH),singlet oxygen(^(1)O_(2)),and superoxide radicals(·O_(2)^(-))were quite different:10^(9)–10^(10),10^(7)–10^(8),and about 10^(5) M^(-1) s^(-1),respectively.The susceptibility of four viruses to ROS varied significantly,in the order of phi6>MS2>phix174>T4.More importantly,^(1)O_(2) can better oxidize capsid proteins.·O_(2)^(-)induced RNA damage was significantly greater than that to the DNA genome,indicating that RNA viruses are more susceptible.·OH can strongly inactivate the four structurally distinct viruses.Furthermore,the resistance of the ROS-inactivated virus to environmental interference was assessed in detail.This study advanced the under-standing of heterogeneity in susceptibility of structurally distinct viruses to various ROS and provided a valuable theoretical basis for the application of AOPs in water disinfection.展开更多
With the deep integration of electrochemical research with energy,environment,catalysis,and other fields,more and more new electrochemical catalytic reactions have entered our research field.Alloy catalysts have recen...With the deep integration of electrochemical research with energy,environment,catalysis,and other fields,more and more new electrochemical catalytic reactions have entered our research field.Alloy catalysts have recently emerged as a new type of nanomaterial due to the rapid development of kinetic controlled synthesis technology.These materials offer several advantages over monometallic catalysts,including larger element combinations,complex geometries,bifunctional sites,and reduced use of precious metals.This paper provides a review of alloy electrocatalysts that are designed and prepared specifically for electrocatalytic applications.The use of alloy materials in electrocatalyst design is also discussed,highlighting their widespread application in this field.First,various synthesis methods and synthesis mechanisms are systematically summarized.Following that,by correlating the properties of materials with the structure,relevant strategies toward advanced alloy electrocatalysts including composition regulation,size,morphology,surface engineering,defect engineering,interface engineering and strain engineering are classified.In addition,the important electrocatalytic applications and mechanisms of alloy electrocatalysts are described and summarized.Finally,the current challenges and prospects regarding the development of alloy nanomaterials are proposed.This review serves as a springboard from a fundamental understanding of alloy structural dynamics to design and various applications of electrocatalysts,particularly in energy and environmental sustainability.展开更多
This study evaluates the applicability of nano-sized calcium peroxide(CaO_(2))as a source of H_(2)O_(2)to remediate 2,4-dichlorophenol(2,4-DCP)contaminated groundwater via the advanced oxidation process(AOP).First,the...This study evaluates the applicability of nano-sized calcium peroxide(CaO_(2))as a source of H_(2)O_(2)to remediate 2,4-dichlorophenol(2,4-DCP)contaminated groundwater via the advanced oxidation process(AOP).First,the effect and mechanism of 2,4-DCP degradation by CaO_(2)at different Fe concentrations were studied(Fenton reaction).We found that at high Fe concentrations,2,4-DCP almost completely degrades via primarily the oxidation of·OH within 5 h.At low Fe concentrations,the degradation rate of 2,4-DCP decreased rapidly.The main mechanism was the combined action of·OH and O_(2)^(·−).Without Fe,the 2,4-DCP degradation reached 13.6%in 213 h,primarily via the heterogeneous reaction on the surface of CaO_(2).Besides,2,4-DCP degradation was significantly affected by solution pH.When the solution pH was>10,the degradation was almost completely inhibited.Thus,we adopted a two-dimensional water tank experiment to study the remediation efficiency CaO_(2)on the water sample.We noticed that the degradation took place mainly in regions of pH<10(i.e.,CaO_(2)distribution area),both upstream and downstream of the tank.After 28 days of treatment,the average 2,4-DCP degradation level was≈36.5%.Given the inadequacy of the results,we recommend that groundwater remediation using nano CaO_(2):(1)a buffer solution should be added to retard the rapid increase in pH,and(2)the nano CaO_(2)should be injected copiously in batches to reduce CaO_(2)deposition.展开更多
Snowmelt runoff is a vital source of fresh water in cold regions. Accurate snowmelt runoff forecasting is crucial in supporting the integrated management of water resources in these regions. However, the performances ...Snowmelt runoff is a vital source of fresh water in cold regions. Accurate snowmelt runoff forecasting is crucial in supporting the integrated management of water resources in these regions. However, the performances of such forecasts are often very low as they involve many meteorological factors and complex physical processes. Aiming to improve the understanding of these influencing factors on snowmelt runoff forecast, this study investigated the time lag of various meteorological factors before identifying the key factor in snowmelt processes. The results show that solar radiation, followed by temperature, are the two critical influencing factors with time lags being 0 and 2 days, respectively. This study further quantifies the effect of the two factors in terms of their contribution rate using a set of empirical equations developed. Their contribution rates as to yearly snowmelt runoff are found to be 56% and 44%, respectively. A mid-long term snowmelt forecasting model is developed using machine learning techniques and the identified most critical influencing factor with the biggest contribution rate. It is shown that forecasting based on Supporting Vector Regression(SVR) method can meet the requirements of forecast standards.展开更多
Cobalt oxyhydroxide(CoOOH)has been turned out to be a high-efficiency catalyst for peroxymonosulfate(PMS)activation.In this study,CoOOH was loaded on bismuth oxide(Bi_(2)O_(3))using a facile chemical precipitation pro...Cobalt oxyhydroxide(CoOOH)has been turned out to be a high-efficiency catalyst for peroxymonosulfate(PMS)activation.In this study,CoOOH was loaded on bismuth oxide(Bi_(2)O_(3))using a facile chemical precipitation process to improve its catalytic activity and stability.The result showed that the catalytic performance on the 2,4-dichlorophenol(2,4-DCP)degradation was significantly enhanced with only 11 wt%Bi_(2)O_(3)loading.The degradation rate in the CoOOH@Bi_(2)O_(3)/PMS system(0.2011 min−1)was nearly 6.0 times higher than that in the CoOOH/PMS system(0.0337 min−1).Furthermore,CoOOH@Bi_(2)O_(3)displayed better stability with less Co ions leaching(16.4%lower than CoOOH)in the PMS system.These phenomena were attributed to the Bi_(2)O_(3)loading which significantly increased the conductivity and specific surface area of the CoOOH@Bi_(2)O_(3)composite.Faster electron transfer facilitated the redox reaction of Co(III)/Co(II)and thus was more favorable for reactive oxygen species(ROS)generation.Meanwhile,larger specific surface area furnished more active sites for PMS activation.More importantly,there were both non-radical(^(1)O_(2))and radicals(SO_(4)^(−)•,O_(2)^(−)•,and OH•)in the CoOOH@Bi_(2)O_(3)/PMS system and^(1)O_(2)was the dominant one.In general,this study provided a simple and practical strategy to enhance the catalytic activity and stability of cobalt oxyhydroxide in the PMS system.展开更多
Groundwater contamination source identification(GCSI)is a prerequisite for contamination risk evaluation and efficient groundwater contamination remediation programs.The boundary condition generally is set as known va...Groundwater contamination source identification(GCSI)is a prerequisite for contamination risk evaluation and efficient groundwater contamination remediation programs.The boundary condition generally is set as known variables in previous GCSI studies.However,in many practical cases,the boundary condition is complicated and cannot be estimated accurately in advance.Setting the boundary condition as known variables may seriously deviate from the actual situation and lead to distorted identification results.And the results of GCSI are affected by multiple factors,including contaminant source information,model parameters,boundary condition,etc.Therefore,if the boundary condition is not estimated accurately,other factors will also be estimated inaccurately.This study focuses on the unknown boundary condition and proposed to identify three types of unknown variables(contaminant source information,model parameters and boundary condition)innovatively.When simulation-optimization(S-O)method is applied to GCSI,the huge computational load is usually reduced by building surrogate models.However,when building surrogate models,the researchers need to select the models and optimize the hyperparameters to make the model powerful,which can be a lengthy process.The automated machine learning(AutoML)method was used to build surrogate model,which automates the model selection and hyperparameter optimization in machine learning engineering,largely reducing human operations and saving time.The accuracy of AutoML surrogate model is compared with the surrogate model used in eXtreme Gradient Boosting method(XGBoost),random forest method(RF),extra trees regressor method(ETR)and elasticnet method(EN)respectively,which are automatically selected in AutoML engineering.The results show that the surrogate model constructed by AutoML method has the best accuracy compared with the other four methods.This study provides reliable and strong support for GCSI.展开更多
Single-atom catalysts(SACs)offer an efficient solution to the sluggish oxygen reduction reaction(ORR)kinetics,providing atomic sites with outstanding catalytic efficiency while enabling precise tailoring and customisa...Single-atom catalysts(SACs)offer an efficient solution to the sluggish oxygen reduction reaction(ORR)kinetics,providing atomic sites with outstanding catalytic efficiency while enabling precise tailoring and customisation of their electron structure[1],[2],[3].Among SACs,3d transition metals stand out for their intrinsic activity that is attributed to the unfilled 3d valence electrons,but suffer from the processes such as the Fenton reaction,steric hindrance,and demetallisation[4],[5],[6].However,low-cost main-group metals(e.g.,Sb and Sn)lack host orbitals(delocalized s/p bands)for electron transfer between reaction species and active sites,resulting in poor intrinsic activity and limited operational pathways[7],[8].Hence,it is urgent to devise mechanisms for activating inert electron configurations in ORR.展开更多
基金supported by the National Natural Science Foundation of China(Nos.52100087,52170079,U20A20322)Science and Technology Development Program of Jilin Province,China(Nos.20220508100RC,20230402035GH).
文摘Rational tuning of crystallographic surface and metal doping were effective to enhance the catalytic performance of metal organic frameworks,but limited work has been explored for achieving modulation of crystal facets and metal doping in a single system.MIL-68(In)was promising for photocatalytic applications due to its low toxicity and excellent photoresponsivity.However,its catalytic activity was constrained by severe carrier recombination and a lack of active sites.Herein,increased(001)facet ratio and active sites exposure were simultaneously realized by cobalt doping in MIL-68(In)through a one-pot solvothermal strategy.Optimized MIL-68(In/Co)-2.5 exhibited remarkable catalytic performance in comparison with pristine MIL-68(In)and other MIL-68(In/Co).The reaction kinetic constant and degradation efficiency of MIL-68(In/Co)were approximately twice and 17%higher than the pristine MIL-68(In)in 36 min reaction,respectively.Density functional theory calculations revealed that Co dopant could modulate the orientation of MIL-68(In)facets,facilitate the exchange of electrons and reduce the adsorption energy of peroxymonosulfate(PMS).This work provides a novel pathway for improvement of In-based MOFs in PMS/vis system,it also promotes the profound comprehension of the correlation between crystal facet regulation and catalytic activation in the PMS/vis system.
文摘Triclosan(TCS) poses harmful risks to ecosystems and human health owing to its endocrine-disrupting effects.Therefore,developing an efficient and sustainable technology to degrade TCS is urgently needed.Herein,cobalt oxyhydroxide @covalent organic frameworks(CoOOH@COFs) S-scheme heterojunction was synthesized,which combined the visible-light-driven photocatalysis and peroxymonosulfate(PMS) activation to synergistically generate abundant reactive oxygen species(ROSs) for TCS degradation.The degradation efficiency of TCS reached 100 % within 8 min in the Vis-CoOOH@COFs/PMS system,and the reaction rate constant was 0.456 min^(-1),which was nearly 1.90 and 2.85 times that of single Co OOH and COFs,and2.36 times that under dark condition,respectively.The density functional theory(DFT) calculations confirmed the energy band bending of CoOOH@COFs and S-scheme charge transport from COFs to Co OOH.Both experimental and theoretical analyses indicated that Co OOH@COFs in photocatalytic-PMS activation systems synergistically facilitated photo-generated carrier separation,enhanced interfacial electron transfer,accelerated PMS activation,and generated multiple ROSs.In particular,photogenerated electrons(e^(-))accelerated the Co(Ⅲ)/Co(Ⅱ) redox cycle,while the PMS captured the e-,which significantly decreased the charge combination of Co OOH@COFs.Radicals(O_(2)^(·-),^(·)OH,and SO_(4)^(·-)) and non-radicals(such as ^(1)O_(2),h^(+),and e^(-)) were both presented in the Vis-CoOOH@COFs/PMS system,with O_(2)^(-) playing a dominant role in TCS degradation.Furthermore,the pathway of TCS degradation and toxicity of intermediates were explored by DFT calculation and transformation product identification.Importantly,the environmentally friendly CoOOH@COFs S-scheme heterojunction exhibited excellent stability and reusability.In conclusion,this study innovatively designed an S-scheme heterojunction in the photocatalytic-PMS activation system,providing guidance and theoretical support for efficient and eco-friendly wastewater treatment.
基金supported by the National Natural Science Foundation of China(Nos.51678270,21872063)111 Project of Jilin University,China(No.B16020)。
文摘The extensive use of tetracycline hydrochloride(TCH)poses a threat to human health and the aquatic environment.Here,magnetic p-n Bi2WO6/CuFe2O4 catalyst was fabricated to efficiently remove TCH.The obtained Bi2WO6/CuFe2O4 exhibited 92.1%TCH degradation efficiency and 50.7%and 35.1%mineralization performance for TCH and raw secondary effluent from a wastewater treatment plant in a photo-Fenton-like system,respectively.The remarkable performance was attributed to the fact that photogenerated electrons accelerated the Fe(III)/Fe(II)and Cu(II)/Cu(I)conversion for the Fenton-like reaction between Fe(II)/Cu(I)and H2O2,thereby generating abundant·OH for pollutant oxidation.Various environmental factors including H2O2 concentration,initial pH,catalyst dosage,TCH concentration and inorganic ions were explored.The reactive oxidation species(ROS)quenching results and electron spin resonance(ESR)spectra confirmed that·O2-and·OH were responsible for the dark and photo-Fenton-like systems,respectively.The degradation mechanisms and pathways of TCH were proposed,and the toxicity of products was evaluated.This work contributes a highly efficient and environmentally friendly catalyst and provides a clear mechanistic explanation for the removal of antibiotic pollutants in environmental remediation.
基金supported by the National Key R&D Program of China(Grant No.2018YFE0111300)funded by the Engineering Research Center of Geothermal Resources Development Technology and Equipment,Ministry of Education,Jilin University。
文摘The Roosevelt Hot Springs Known Geothermal Resource Area(KGRA) is a Basin and Range-type geothermal resource, which is located in southwestern Utah. The integrated multicomponent geothermometry(IMG) approach is used to estimate the reservoir temperature at the Roosevelt Hot Springs KGRA. Geothermometric modeling results indicate the deep reservoir temperature is approximately 284.6°C. A conceptual model of the Roosevelt Hot Spring KGRA is provided through integrating the various pieces of exploration information, including the geological data, geothermometric results, temperature well log and field evidence. A two-dimensional cross-sectional model was thus built to quantitatively investigate the coupled thermal-hydraulic processes in the Roosevelt geothermal field. By matching the preproduction temperature log data of deep wells, parameters controlling flow and heat transport are identified. The method and model presented here may be useful for other geothermal fields with similar conditions.
基金funded by the National Key R&D Program of China (No.2018YFC0406503)the National Natural Science Foundation of China (No.52070086)+1 种基金the Natural Science Foundation of Jilin Provincial Science & Technology Department (No.20200403034SF)the Open Project Program of Engineering Research Center of Groundwater Pollution Control and Remediation,Ministry of Education。
文摘As an antibiotic,sulfadiazine has posed a serious threat to humans and ecosystems due to its chronic toxicity.The advanced oxidation processes (AOPs) via heterogeneous catalytic activation of peroxymonosulfate (PMS) have significant potential for the degradation of antibiotics.However,there are multiple restrictions including non-specifically binding to target contaminants,which would deplete oxidation capacity,and lacking energy effectiveness due to inefficient utilization of reactive oxygen species (ROS).To overcome these obstacles,we adopted the“bait-hook&destroy”strategy in this study.Herein,we synthesized a novel micrometer-sized Ni OOH hierarchical spheres assembled from nanosheets,which have relatively large specific surface areas and yield specified cavities to“bait-hook”sulfadiazine and PMS onto the surface cavities.This process was further conductive to effective generation of ROS and subsequently“destruction”of sulfadiazine with elevated mass transformation rate.20.4%of sulfadiazine can adsorb to Ni OOH surface in less than 30 min (0.0051 min^(-1)),and then sulfadiazine was completely degraded in 90min intervals in the Ni OOH/PMS system.The degradation rate constant (k=0.0537 min^(-1)) was about5.3,2.5 and 2.2 times higher than that in Ni_(2)O_(3)/PMS,NiO/PMS and Ni(OH)_(2)/PMS system,respectively.This was ascribed to the synergistic catalytic oxidation and adsorption process occurred on the surface of Ni OOH.Appreciably,there were both non-radicals (^(1)O_(2)) and radicals (O_(2)^(·-)and SO_(4)^(·-)) involved in the Ni OOH/PMS system,and^(1)O_(2)was distinguished as the dominated ROS for degradation of sulfadiazine.This study provides a novel strategy via synergistic adsorption and catalytic oxidation,and indicates that the micrometer-sized Ni OOH hierarchical sphere as heterogeneous catalyst is an attractive candidate for potential application of the SR-AOPs technology in water treatment.
文摘Covalent organic frameworks(COFs)have attracted attention as photocatalysts,however,low electron transfer and reactive oxygen species(ROS)generation still hinder their photocatalytic application.In this work,we construct multivariate donor-acceptor(D-A)heterojunctions in the covalent organic frameworks by synchronously introducing electron-withdrawing and donating substituents.Importantly,the optoelectronic characteristics and visible-light photocatalytic performance were improved with the increase of the electron donor carbon chains in multivariate D-A COFs.Combining in‐situ characterization with theoretical calculations,the charge carrier separation and transfer efficiency,•O_(2)–generation and conversion,and the energy barrier of the rate determination steps related to the formation of*OH and*OOH,can be well regulated by the multivariate D-A COFs.More importantly,the ortho-carbon atom of the Br and OCH_(3) group-linked benzene rings and the imine bond(–C=N–)in COF-Br@OCH_(3) were activated to produce the key*OH and*OOH intermediates for effectively reducing the energy barrier of H2O oxidation and O_(2) reduction.This work provides valuable insights into the precise design and synthesis of COFs-based catalysts and the regulation of electron transfer and ROS generation by modulating the electron-withdrawing and donating substituents for highly efficient visible-light photocatalytic degradation of refractory organic pollutants.
基金supported by the National Key R&D Program of China(Grant No.2018YFE0111300)the Project of Science and Technology Department of Jilin Province(Grant No.20200403147SF)the Project of Education Department of Jilin Province(Grant No.JJKH20201003KJ)。
文摘Enhanced geothermal system(EGS) is an effective method for developing and utilizing hot dry rock(HDR). The key to the effectiveness of EGS is the construction of an artificial fracture network. The permeability of fractures has severe effects on the heat transfer efficiency and sustainability of geothermal energy. However, the evolution characteristics of hydraulic conductivity under different failure modes have not been adequately studied for HDR. To clarify this, rocks with different failure modes were investigated by conducting thermal triaxial compression experiments, and the fluid seepage related to different rock failure modes was comprehensively investigated. The results showed that the characteristic stresses and crack surface roughness of the rock increased as the confining pressure increased. The permeability in the composited failure mode was the largest(11.4 μm;), followed by that in the Y-shaped shear failure mode(9.7 μm;), and that in the single-shear failure mode was the smallest(7.2 μm;). The confining pressures had an inhibitory effect on permeability. As the confining pressure increased from 5 to 30 MPa, the permeability decreased by 88.8%, 88.4%, and 89.9%, respectively. In contrast, the permeability was significantly enhanced by 128.3%, 94.6%, and 131% as the flow rate increased from 3 to 7 m L/min.
基金financially supported by the National Natural Science Foundation of China(Nos.52170079 and U20A20322)the Programme of Introducing Talents of Discipline to Universities,China(No.B16020)。
文摘The Z-scheme heterostructure for photocatalyst can effectively prolong the lifetime of photogenerated carriers and retain a higher conduction/valence band position,promoting the synergistic coupling of photocatalysis and peroxymonosulfate(PMS) activation.In order to fully utilize the luminous energy and realize the efficient activation of PMS,this work achieved successful construction of NiCo_(2)O_(4)/BiOCl/Bi_(24)O_(31)Br_(10) ternary Z-scheme heterojunction by simultaneously synthesizing BiOCl and NiCo_(2)O_(4) with NiCl_(2) and CoCl_(2) as the precursors.The intercalated BiOCl could serve as a carrier migration ladder to further achieve the spatial separation of electron-hole pairs,so that the oxidation and reduction processes separately occurred in different regions.Compared with the reported catalysts,the as-prepared composites exhibited the enhanced removal efficiency for tetracycline hydrochloride(TCH) in the visible light/PMS system,with a degradation efficiency of 85.30%in 2 min,and possessed good stability.Z-scheme heterojunction was shown to be beneficial for maximizing the superiority of photo-assisted Fenton-like reaction system.The experimental and characterization results confirmed that both non-radicals(^(1)O_(2)) and radicals(SO_(5)^(·-) and SO_(4)^(·-)) were involved in the reaction process and the SO_(5)^(·-)generated by the oxidation of PMS played a crucial role in the TCH degradation.The possible reaction mechanism was finally proposed.This study provided new insight into the Z-scheme heterostructure to promote the photo-assisted Fenton-like reaction.
基金financially supported by the Fundamental Research Funds for the Central Universities of ChinaKey Project of National Natural Science Foundation of China(No.41530636)
文摘In this study,sodium tripolyphosphate(STPP)was used to promote the removal of organic pollutants in a zero-valent copper(ZVC)/O2 system under neutral conditions for the first time.20 mg/L p-nitrophenol(PNP)can be completely decomposed within 120 min in the ZVC/O2/STPP system.The PNP degradation process followed pseudo-first-order kinetics and the degradation rate of PNP gradually increased upon the decreasing ZVC particle size.The optimal pH of the reaction system was 5.0.Our mechanism investigation showed that Cu+generated by ZVC corrosion was the main reducing agent for the activation of 02 to produce ROS.-OH was identified as the only ROS formed during the degradation of PNP and its production pathway was the double-electron activation of O2(O2→H2 O2→·OH).In this process,STPP did not only promote the release of Cu+through its complexation,but also promoted the production of OH by reducing the redox potential of Cu2+/Cu+.In addition,we could initiate and terminate the reaction by controlling the pH.At pH<8.1,ZVC/02/STPP could continuously degrade organic pollutants;at pH>8.1,the reaction was terminated.STPP was recycled to continuously promote the corrosion of ZVC and O2 activation as long as the pH was<8.1.This study provided a new and efficient way for O2 activation and organic contaminants removal.
基金supported by the National Natural Science Foundation of China(Nos.42276224 and 42206230)the Jilin Scientific and Technological Development Program(No.20190303083SF)+1 种基金the International Cooperation Key Laboratory of Underground Energy Development and Geological Restoration(No.YDZJ202102CXJD014)the Graduate Innovation Fund of Jilin University(No.2023CX100).
文摘As an important source of low-carbon,clean fossil energy,natural gas hydrate plays an important role in improving the global energy consumption structure.Developing the hydrate industry in the South China Sea is important to achieving‘carbon peak and carbon neutrality’goals as soon as possible.Deep-water areas subjected to the action of long-term stress and tectonic movement have developed complex and volatile terrains,and as such,the morphologies of hydrate-bearing sediments(HBSs)fluctuate correspondingly.The key to numerically simulating HBS morphologies is the establishment of the conceptual model,which represents the objective and real description of the actual geological body.However,current numerical simulation models have characterized HBSs into horizontal strata without considering the fluctuation characteristics.Simply representing the HBS as a horizontal element reduces simulation accuracy.Therefore,the commonly used horizontal HBS model and a model considering the HBS’s fluctuation characteristics with the data of the SH2 site in the Shenhu Sea area were first constructed in this paper.Then,their production behaviors were compared,and the huge impact of the fluctuation characteristics on HBS production was determined.On this basis,the key parameters affecting the depressurization production of the fluctuating HBSs were studied and optimized.The research results show that the fluctuation characteristics have an obvious influence on the hydrate production of HBSs by affecting their temperatures and pressure distributions,as well as the transmission of the pressure drop and methane gas discharge.Furthermore,the results show that the gas productivity of fluctuating HBSs was about 5%less than that of horizontal HBSs.By optimizing the depressurization amplitude,well length,and layout location of vertical wells,the productivity of fluctuating HBSs increased by about 56.6%.
基金supported by the National Natural Science Foundation of China(No.42276224,No.3A2213285425 and No.42206230).
文摘Natural gas hydrate production involves complex mass/heat transfer,phase transformation,and multiphase seepage processes,where permeability critically influences exploitation efficiency and sediment stability.This review summarizes progress in permeability evolution in hydrate-bearing sediments,covering:multiphase seepage theories involving absolute and relative permeability models;pore-scale methods,including Lattice Boltzmann,Pore Network models,CFD simulations,and microfluidic experiments,for investigating the effects of hydrate morphology and pore heterogeneity;core-scale experiments,such as seepage tests and X-ray CT,for quantifying permeability changes with hydrate saturation and stress sensitivity;site-scale scenarios involving pilot tests and numerical models are challenged by fluid migration prediction and reservoir stability.Key findings show hydrate dissociation induces dynamic pore structure changes and complex multiphase interactions,with existing models oversimplifying heterogeneous pore structures and hydrate distributions.Critical research gaps include:inadequate characterization of pore structure evolution during hydrate nucleation/dissociation;unclear gas-water flow mechanisms in deformable sediments;lack of multiscale correlation and coupled modeling for permeability-stress-phase change interactions.Addressing these offers critical insights for optimizing extraction,reducing energy use,and ensuring reservoir stability,enabling safe and efficient exploitation of natural gas hydrates as a strategic clean energy resource.
基金funded by the Science and Technology Development Program of Jilin Province,China(No.20220101214JC).
文摘Waterborne viruses have caused outbreaks of related diseases and threaten human health,and advanced oxidation processes(AOPs),as clean and efficient technologies,have received widespread attention for their excellent performance in inactivating viruses.However,heterogeneity in susceptibility of structurally distinct viruses to various reactive oxygen species(ROS)is unclear.This study first measured the heterogeneity in inactivation kinetics and biological mechanisms of four typical viral surrogates(MS2,phi6,phix174,and T4)to various ROS by visible light catalysis.Notably,the second-order inactivation rate constants of four viruses by hydroxyl radicals(·OH),singlet oxygen(^(1)O_(2)),and superoxide radicals(·O_(2)^(-))were quite different:10^(9)–10^(10),10^(7)–10^(8),and about 10^(5) M^(-1) s^(-1),respectively.The susceptibility of four viruses to ROS varied significantly,in the order of phi6>MS2>phix174>T4.More importantly,^(1)O_(2) can better oxidize capsid proteins.·O_(2)^(-)induced RNA damage was significantly greater than that to the DNA genome,indicating that RNA viruses are more susceptible.·OH can strongly inactivate the four structurally distinct viruses.Furthermore,the resistance of the ROS-inactivated virus to environmental interference was assessed in detail.This study advanced the under-standing of heterogeneity in susceptibility of structurally distinct viruses to various ROS and provided a valuable theoretical basis for the application of AOPs in water disinfection.
基金supported by the National Natural Science Foundation of China(No.52072153)the Postdoctoral Science Foundation of China(No.2021M690023)+2 种基金the Postdoctoral Science Foundation of Jiangsu Province(No.2021K176B)the Graduate Research Innovation Program of Jiangsu Provincial(Nos.KYCX22_3694 and KYCX23_3649)the Zhenjiang Key R&D Programmes(No.SH2021021)。
文摘With the deep integration of electrochemical research with energy,environment,catalysis,and other fields,more and more new electrochemical catalytic reactions have entered our research field.Alloy catalysts have recently emerged as a new type of nanomaterial due to the rapid development of kinetic controlled synthesis technology.These materials offer several advantages over monometallic catalysts,including larger element combinations,complex geometries,bifunctional sites,and reduced use of precious metals.This paper provides a review of alloy electrocatalysts that are designed and prepared specifically for electrocatalytic applications.The use of alloy materials in electrocatalyst design is also discussed,highlighting their widespread application in this field.First,various synthesis methods and synthesis mechanisms are systematically summarized.Following that,by correlating the properties of materials with the structure,relevant strategies toward advanced alloy electrocatalysts including composition regulation,size,morphology,surface engineering,defect engineering,interface engineering and strain engineering are classified.In addition,the important electrocatalytic applications and mechanisms of alloy electrocatalysts are described and summarized.Finally,the current challenges and prospects regarding the development of alloy nanomaterials are proposed.This review serves as a springboard from a fundamental understanding of alloy structural dynamics to design and various applications of electrocatalysts,particularly in energy and environmental sustainability.
基金the National Key R&D Program of China(No.2018YFC1802500).
文摘This study evaluates the applicability of nano-sized calcium peroxide(CaO_(2))as a source of H_(2)O_(2)to remediate 2,4-dichlorophenol(2,4-DCP)contaminated groundwater via the advanced oxidation process(AOP).First,the effect and mechanism of 2,4-DCP degradation by CaO_(2)at different Fe concentrations were studied(Fenton reaction).We found that at high Fe concentrations,2,4-DCP almost completely degrades via primarily the oxidation of·OH within 5 h.At low Fe concentrations,the degradation rate of 2,4-DCP decreased rapidly.The main mechanism was the combined action of·OH and O_(2)^(·−).Without Fe,the 2,4-DCP degradation reached 13.6%in 213 h,primarily via the heterogeneous reaction on the surface of CaO_(2).Besides,2,4-DCP degradation was significantly affected by solution pH.When the solution pH was>10,the degradation was almost completely inhibited.Thus,we adopted a two-dimensional water tank experiment to study the remediation efficiency CaO_(2)on the water sample.We noticed that the degradation took place mainly in regions of pH<10(i.e.,CaO_(2)distribution area),both upstream and downstream of the tank.After 28 days of treatment,the average 2,4-DCP degradation level was≈36.5%.Given the inadequacy of the results,we recommend that groundwater remediation using nano CaO_(2):(1)a buffer solution should be added to retard the rapid increase in pH,and(2)the nano CaO_(2)should be injected copiously in batches to reduce CaO_(2)deposition.
基金The Key Program of National Natural Science Foundation of China,No.42230204。
文摘Snowmelt runoff is a vital source of fresh water in cold regions. Accurate snowmelt runoff forecasting is crucial in supporting the integrated management of water resources in these regions. However, the performances of such forecasts are often very low as they involve many meteorological factors and complex physical processes. Aiming to improve the understanding of these influencing factors on snowmelt runoff forecast, this study investigated the time lag of various meteorological factors before identifying the key factor in snowmelt processes. The results show that solar radiation, followed by temperature, are the two critical influencing factors with time lags being 0 and 2 days, respectively. This study further quantifies the effect of the two factors in terms of their contribution rate using a set of empirical equations developed. Their contribution rates as to yearly snowmelt runoff are found to be 56% and 44%, respectively. A mid-long term snowmelt forecasting model is developed using machine learning techniques and the identified most critical influencing factor with the biggest contribution rate. It is shown that forecasting based on Supporting Vector Regression(SVR) method can meet the requirements of forecast standards.
基金The present work was funded by the Natural Science Foundation of Jilin Provincial Science&Technology Department(Grant No.20180101081JC,20200403034SFthe Science and Technology Project of the Education Department of Jilin Province(Grant No.JJKH20190125KJ).Besides,we would thank to the supervision of Professor Wei Feng from Jilin University for this work.
文摘Cobalt oxyhydroxide(CoOOH)has been turned out to be a high-efficiency catalyst for peroxymonosulfate(PMS)activation.In this study,CoOOH was loaded on bismuth oxide(Bi_(2)O_(3))using a facile chemical precipitation process to improve its catalytic activity and stability.The result showed that the catalytic performance on the 2,4-dichlorophenol(2,4-DCP)degradation was significantly enhanced with only 11 wt%Bi_(2)O_(3)loading.The degradation rate in the CoOOH@Bi_(2)O_(3)/PMS system(0.2011 min−1)was nearly 6.0 times higher than that in the CoOOH/PMS system(0.0337 min−1).Furthermore,CoOOH@Bi_(2)O_(3)displayed better stability with less Co ions leaching(16.4%lower than CoOOH)in the PMS system.These phenomena were attributed to the Bi_(2)O_(3)loading which significantly increased the conductivity and specific surface area of the CoOOH@Bi_(2)O_(3)composite.Faster electron transfer facilitated the redox reaction of Co(III)/Co(II)and thus was more favorable for reactive oxygen species(ROS)generation.Meanwhile,larger specific surface area furnished more active sites for PMS activation.More importantly,there were both non-radical(^(1)O_(2))and radicals(SO_(4)^(−)•,O_(2)^(−)•,and OH•)in the CoOOH@Bi_(2)O_(3)/PMS system and^(1)O_(2)was the dominant one.In general,this study provided a simple and practical strategy to enhance the catalytic activity and stability of cobalt oxyhydroxide in the PMS system.
基金supported by the National Natural Science Foundation of China (Grant Nos.42272283 and 41972252)the Graduate Innovation Fund of Jilin University (No.2022186).
文摘Groundwater contamination source identification(GCSI)is a prerequisite for contamination risk evaluation and efficient groundwater contamination remediation programs.The boundary condition generally is set as known variables in previous GCSI studies.However,in many practical cases,the boundary condition is complicated and cannot be estimated accurately in advance.Setting the boundary condition as known variables may seriously deviate from the actual situation and lead to distorted identification results.And the results of GCSI are affected by multiple factors,including contaminant source information,model parameters,boundary condition,etc.Therefore,if the boundary condition is not estimated accurately,other factors will also be estimated inaccurately.This study focuses on the unknown boundary condition and proposed to identify three types of unknown variables(contaminant source information,model parameters and boundary condition)innovatively.When simulation-optimization(S-O)method is applied to GCSI,the huge computational load is usually reduced by building surrogate models.However,when building surrogate models,the researchers need to select the models and optimize the hyperparameters to make the model powerful,which can be a lengthy process.The automated machine learning(AutoML)method was used to build surrogate model,which automates the model selection and hyperparameter optimization in machine learning engineering,largely reducing human operations and saving time.The accuracy of AutoML surrogate model is compared with the surrogate model used in eXtreme Gradient Boosting method(XGBoost),random forest method(RF),extra trees regressor method(ETR)and elasticnet method(EN)respectively,which are automatically selected in AutoML engineering.The results show that the surrogate model constructed by AutoML method has the best accuracy compared with the other four methods.This study provides reliable and strong support for GCSI.
基金National Natural Science Foundation of China(51872115 and 52272209).
文摘Single-atom catalysts(SACs)offer an efficient solution to the sluggish oxygen reduction reaction(ORR)kinetics,providing atomic sites with outstanding catalytic efficiency while enabling precise tailoring and customisation of their electron structure[1],[2],[3].Among SACs,3d transition metals stand out for their intrinsic activity that is attributed to the unfilled 3d valence electrons,but suffer from the processes such as the Fenton reaction,steric hindrance,and demetallisation[4],[5],[6].However,low-cost main-group metals(e.g.,Sb and Sn)lack host orbitals(delocalized s/p bands)for electron transfer between reaction species and active sites,resulting in poor intrinsic activity and limited operational pathways[7],[8].Hence,it is urgent to devise mechanisms for activating inert electron configurations in ORR.
