In this work,we constructed a three-dimensional electrochemical system(3D-ECO),which included the cathode and anode electrode plates,as well as the screening of three-dimensional particle electrodes and parameter opti...In this work,we constructed a three-dimensional electrochemical system(3D-ECO),which included the cathode and anode electrode plates,as well as the screening of three-dimensional particle electrodes and parameter opti-mization,for the degradation of landfill leachate(LL)containing elevated levels of tetracycline(TC),and explored its mechanism of action.Firstly,titanium-based ruthenium-iridium(Ti/RuO_(2)-IrO_(2)),titanium-based ruthenium-iridium-platinum(Ti/Pt-RuO_(2)-IrO_(2)),and titanium-based tin-antimony(Ti/SnO_(2)-Sb_(2)O_(3))were employed as an-odes in the electrocatalytic oxidation system,with titanium and stainless steel plates serving as cathodes,to construct the optimal two-dimensional electrocatalytic oxidation system(2D-ECO)through cross-comparison ex-periments.Subsequently,using granular activated carbon(GAC),coconut shell biochar(CBC),walnut shell carbon(WBC),and bamboo charcoal(BBC)as particle electrodes,a 3D-ECO system was developed.The influence of var-ious operational parameters on treating TC-containing LL was investigated.The optimal operating parameters obtained from the study was:pH=5,current density of 30 mA/cm^(2),particle dosage of 7 g/L,particle size ranging from 1.70 to 2.00 mm,and electrode spacing of 4 cm.Under these conditions,the COD removal rate of 3D-ECO within three hours was 90.25%,the TC removal rate was 72.41%,and the NH_(3)-N removal rate was 39.52%.The removal of TC followed a pseudo-first-order kinetic model.Additionally,degradation mechanisms were elucidated through electron paramagnetic resonance(EPR)spectrometer and Tert-Butanol(TBA)quenching experiments,indicating that the degradation primarily occurred through a non-radical(1O_(2))pathway.This re-search offers a comprehensive analysis of the simultaneous breakdown of intricate LL matrices and TC,enhancing our comprehension of the degradation processes and underlying mechanisms.展开更多
Superoxide dismutase 1(SOD1)is a thermodynamically stable,zinc and copper binding homodimeric enzyme responsible for breaking down superoxide radicals.More than 200,mostly missense,mutations spread throughout the SOD1...Superoxide dismutase 1(SOD1)is a thermodynamically stable,zinc and copper binding homodimeric enzyme responsible for breaking down superoxide radicals.More than 200,mostly missense,mutations spread throughout the SOD1 gene are associated with the fatal neurodegenerative disease,amyotrophic lateral sclerosis(ALS).A unifying feature of ALS-associated SOD1 mutations is the destabilization of the SOD1 protein structure,increasing the propensity for misfolding and subsequent pathological aggregation.Post-mortem analysis of SOD1-associated ALS tissue shows the accumulation of misfolded SOD1 protein and ubiquitinated SOD1 inclusions within motor neurons.Misfolded SOD1 accumulation and aggregates are implicated in cellular dysfunction via a number of disparate but critical processes,including endoplasmic reticulum stress,oxidative damage,proteasome dysfunction,axonal transport abnormalities and synaptic dysfunction;culminating in motor neuron degeneration associated with ALS.展开更多
Enhancing the activity of photocatalysts is a critical challenge for improving the photocatalytic degradation of contaminated wastewater.Here,a novel Ce single-atom-doped titanate nanotube photocatalyst(CeH_(2)Ti_(2)O...Enhancing the activity of photocatalysts is a critical challenge for improving the photocatalytic degradation of contaminated wastewater.Here,a novel Ce single-atom-doped titanate nanotube photocatalyst(CeH_(2)Ti_(2)O_(5)·H_(2)O)was successfully synthesized using a onepot solvothermal method.Degradation experiments revealed that the optimal Ce doping ratio was 1.0%.The ultraviolet-visible diffuse reflectance spectroscopy results showed that the bandgap of the Ce-doped sample decreased from 3.02 to 2.87 eV,enhancing the absorption in the visible spectral range.At the same time,the BrunauerEmmett-Teller specific surface area increased from 63.68 to 88.95 m^(2)g^(-1).The 1.0%Ce-H_(2)Ti_(2)O_(5)·H_(2)O(HTC_(1))could degrade 99.04%of 100 mg L-1rhodamine B(RhB)after 40 min of visible-light irradiation.The degradation efficiency decreased by only 21.24%after five cycles.The results of free-radical quenching and electron spin resonance spectroscopy analyses indicated that HTC_(1)achieved efficient degradation of RhB through a direct hole oxidation mechanism.Compared with pure protonated titanate nanotubes(H_(2)Ti_(2)O_(5)·H_(2)O),HTC_(1)had a higher specific surface area,more electron traps,narrower bandgap,longer hole lifetime,and suppressed photogenerated charge recombination rate owing to the Ce single-atom doping.展开更多
The large molecular weight and high hydrophilicity of chloramphenicol(CAP) residuals in wastewater led to severe degradation difficulty,which propelled the development of new wastewater degradation processes and react...The large molecular weight and high hydrophilicity of chloramphenicol(CAP) residuals in wastewater led to severe degradation difficulty,which propelled the development of new wastewater degradation processes and reactors based on process intensification.This study enhanced the CAP degradation by ozone/peroxydisulfate(PDS) advanced oxidation process in a submerged rotating packed bed(SRPB)reactor.Compared the usage of different oxidants,it was indicated that the combination of O_(3) and PDS exhibited a higher degradation efficiency than ozone and PDS alone.The more desired degradation efficiency could be achieved at the operating conditions of ascending PDS concentration,SRPB rotational speed,ozone concentration,reduced initial CAP concentration,and the water qualities of ascended pH,lower Cl^(-)and initial CO_(3)^(2-) concentrations.Under the optimized conditions of C_(CAP)=20 mg·L^(-1),C_(O3)=30 mg·L^(-1),C_(PDS)=100 mg·L^(-1),and N=400 r·min^(-1),and water qualities of pH=10,the maximum chloramphenicol degradation efficiency of 97% and kinetic constant of 0.23 min^(-1) were achieved after treating 16 min.A comparison of the results with previously reported advanced oxidation processes of CAP indicated that the enhanced O^(3)/PDS advanced oxidation system using the SRPB can significantly improve the degradation efficiency of CAP.展开更多
Addressing the growing challenge of water contamination,this study comparatively evaluated a persulfate(PDS)system activated by nonradical nitrogen-doped carbon nanotubes(N-CNTs)versus a PDS system activated by radica...Addressing the growing challenge of water contamination,this study comparatively evaluated a persulfate(PDS)system activated by nonradical nitrogen-doped carbon nanotubes(N-CNTs)versus a PDS system activated by radical-based iron(Fe^(2+)),both used for the degradation of bisphenol A(BPA).The N-CNTs/PDS system,driven by the electron transfer mechanism,achieved remarkable 90.9%BPA removal within 30 min at high BPA concentrations,significantly outperforming the Fe^(2+)/PDS system,which attained only 38.9%removal.The N-CNTs/PDS system maintained robust degradation efficiency across a wide range of BPA concentrations and exhibited a high degree of resilience in diverse water matrices.By directly abstracting electrons from BPA molecules,the N-CNTs/PDS system effectively minimised oxidant wastage and mitigated the risk of secondary pollution,ensuring efficient utilisation of active sites on N-CNTs and sustaining a high catalytic rate.The formation of the N-CNTs-PDS^(*)complex significantly enhanced BPA degradation and mineralisation,thereby optimising PDS consumption.These findings highlight the unparalleled advantages of the N-CNTs/PDS system in managing complex wastewater,offering a promising and innovative solution for treating complex industrial wastewater and advancing environmental remediation efforts.展开更多
Currently,ferrate(VI)oxidation technology(FOT)has been regarded as one of the most promising options for the degradation of emerging organic pollutants.However,the role and transformation of chloride ions(Cl^(−))in FO...Currently,ferrate(VI)oxidation technology(FOT)has been regarded as one of the most promising options for the degradation of emerging organic pollutants.However,the role and transformation of chloride ions(Cl^(−))in FOT have not been well explored.The current study aims to investigate the formation of chlorinated phenolic byproducts upon ferrate(VI)oxidation processes.The obtained results indicate that chlorides suffering ferrate(VI)attack will be transformed to active chlorine species(ACS),which will subsequently lead to the formation of highly toxic aromatic chlorinated byproducts.The identified byproducts include common chlorinated phenolic derivatives,as well as complex chlorinated oligomer byproducts with ether structures(mainly dimers and trimers).While the formation of common chlorophenols can be ascribed to the electrophilic substitution reactions mediated by ACS,the oligomer byproducts are generated via coupling reactions between chlorinated phenoxy radicals.ECOSAR software predicts that the generated chlorinated oligomer byproducts exhibit high ecotoxicological effects.As a whole,the above findings shed light on the potential risk of FOT in real practice.展开更多
Boron-doped diamond （BDD） electrocatalysis is combined with photocatalysis using titanium dioxide （TiO2） as a catalyst to improve pollutant-oxidation efficiency. Phenol solution is chosen as model wastewater. Diff...Boron-doped diamond （BDD） electrocatalysis is combined with photocatalysis using titanium dioxide （TiO2） as a catalyst to improve pollutant-oxidation efficiency. Phenol solution is chosen as model wastewater. Different methods involving BDD and/or TiO2 during the degradation processes are compared. Parameters such as the currency density and initial concentration are varied in order to determine their effects on the oxidation process. Moreover, the degradation kinetics of phenol is experimentally studied. The results reveal the superiority of series combination of BDD and TiO2, especially the treatment process of electrocatalysis and succedent photocatalysis, and the optimum working currency density for electrocatalysis is 25.48 mA/cm2. The removal rate decreases with the increase in the initial phenol concentration and the degradation reaction follows quasi-first-order kinetics equation.展开更多
To mitigate the impact of interdiffusion reactions between the silicide slurry and Ta12W alloy substrate during vacuum sintering process on the oxidation resistance of the silicide coating,a micro-arc oxidation pretre...To mitigate the impact of interdiffusion reactions between the silicide slurry and Ta12W alloy substrate during vacuum sintering process on the oxidation resistance of the silicide coating,a micro-arc oxidation pretreatment was employed to construct a Ta_(2)O_(5)ceramic layer on the Ta12W alloy surface.Subsequently,a slurry spraying-vacuum sintering method was used to prepare a Si-Cr-Ti-Zr coating on the pretreated substrate.Comparative studies were conducted on the microstructure,phase composition,and isothermal oxidation resistance(at 1600℃)of the as-prepared coatings with and without the micro-arc oxidation ceramic layer.The results show that the Ta_(2)O_(5)layer prepared at 400 V is more continuous and has smaller pores than that prepared at 350 V.After microarc oxidation pretreatment,the Si-Cr-Ti-Zr coating on Ta12W alloy consists of three distinct layers:an upper layer dominated by Ti_(5)Si_(3),Ta_(5)Si_(3),and ZrSi;a middle layer dominated by TaSi_(2);a coating/substrate interfacial reaction layer dominated by Ta_(5)Si_(3).Both the Si-Cr-Ti-Zr coatings with and without the Ta_(2)O_(5)ceramic layer do not fail after isothermal oxidation at 1600℃for 5 h.Notably,the addition of the Ta2O5 ceramic layer reduces the high-temperature oxidation rate of the coating.展开更多
Antibiotics are emerging pollutants that pose significant risks to environmental and human health.Periodate(PI)-based advanced oxidation processes have shown promise for their effective degradation.In this study,we sy...Antibiotics are emerging pollutants that pose significant risks to environmental and human health.Periodate(PI)-based advanced oxidation processes have shown promise for their effective degradation.In this study,we systematically investigate the structure-activity relationship of four representative Fe-based metal-organic frameworks(Fe-MOFs)-MIL-101(Fe),MIL-88B(Fe),MIL-88A(Fe),and MIL-53(Fe)-as PI activators for tetracycline(TC)degradation.Among them,MIL-101(Fe)exhibited the highest catalytic performance,owing to its unique Fe3O-OH nodes and mesoporous architecture.The MIL-101(Fe)/PI system achieved 93.3%TC degradation and 55.9%mineralization rate within 60 min.Mechanistic studies combining scavenger quenching,sulfoxide probe transformation,X-ray photoelectron spectroscopy,and X-ray absorption fine structure confirmed the generation of multiple reactive oxygen species,and high-valent Fe(IV)]O and O_(2)^(·-)played major roles in the tetracycline degradation process.Density functional theory calculations further revealed that MIL-101(Fe)and MIL-88B(Fe)effectively interact with PI to form Fe(Ⅲ)-superoxide(Fe(Ⅲ)-O-O^(·-)),a key intermediate in Fe(IV)]O generation.In contrast,the adsorption energy of MIL-53(Fe)and MIL-88A(Fe)was relatively weak,with fewer binding sites,resulting in poor performance.The synergy between Fe(Ⅲ)-O-O^(·-)formation and the pore accessibility of MIL-101(Fe)accounted for its superior catalytic efficiency.This work not only clarifies the structural factors governing PI activation in Fe-MOFs,but also proposes a mechanistically informed strategy for designing high-performance catalysts for antibiotic degradation.展开更多
In this study,sawdust served as a carbon source and urea as a nitrogen source to synthesize carbonsupported,nitrogen-doped TiO_(2)composites via a one-pot solvothermal method.The composites were characterized using FT...In this study,sawdust served as a carbon source and urea as a nitrogen source to synthesize carbonsupported,nitrogen-doped TiO_(2)composites via a one-pot solvothermal method.The composites were characterized using FTIR,powder X-ray diffraction,X-ray photoelectron spectroscopy,ultraviolet-visible diffuse reflectance spectroscopy,thermogravimetry-derivative thermogravimetry,scanning electron microscopy-energy dispersive spectroscopy,and transmission electron microscopy.Results indicated that all synthesized composites exhibit the anatase phase,with those calcined at 800℃ demonstrating enhanced crystallinity.Nitrogen is incorporated into the TiO_(2)lattice,while carbon is predominantly located on the surface.Photodegradation experiments showed that 20 mg of composite N-TiO_(2)/C-800 achieved degradation rates of 93.4% for methylene blue(20 mg·L^(-1),50 mL)and 99.4% for oxytetracycline(20 mg·L^(-1),50 mL)within 30 min.Free radical capture experiments indicated that h+was the primary active species in the photocatalytic degradation process.展开更多
Carbon fiber-reinforced carbon aerogel(C/CA)composites are one of the most promising candidates for applications requiring both thermal insulation and load bearing capabilities.The preparation of anti-oxidation coatin...Carbon fiber-reinforced carbon aerogel(C/CA)composites are one of the most promising candidates for applications requiring both thermal insulation and load bearing capabilities.The preparation of anti-oxidation coatings on C/CA to address its susceptibility to oxidation is a feasible approach to promote its application in oxidative environments.However,the currently reported coatings on C/CA mainly focus on improving the ablation performance and coating preparation process typically necessitating high-temperature heat treatment.This procedure can increase its thermal conductivity and reduce its thermal insulation ability.In this study,a series of ceramic-resin coatings were fabricated on C/CA through a simple slurry brushing-drying approach at room temperature.The effects of phenolic resin content on the coating structure,residual stress,thermal shock,and oxidation behaviors were investigated.Due to the adhesive properties and curing-induced shrinkage,the PR-7.5 coating(containing 7.5%(in mass)phenolic resin in the slurry)exhibits bonding strength close to fracture strength of the substrate and residual compressive stress of 0.853 GPa,which is beneficial for resisting thermal shock cracking.However,excessive resin content(PR-10.0 containing 10.0%(in mass)phenolic resin in the slurry)induces tensile stress due to uneven curing shrinkage,thereby leading to thermal shock cracking.Meanwhile,oxidation tests reveal significantly reduced weight losses for PR-7.5(17.46%at 800℃/100 min,8.15%at 1000℃/120 min,3.15%at 1200℃/120 min)versus uncoated C/CA’s 44.60%loss at 800℃/20 min.This work provides a brand-new and simple approach to improving the anti-oxidation performance of C/CA and expands its application in mild oxidative environments.展开更多
The microbial degradation of aromatic organic pollutants is incomplete due to their metabolic characteristics,which can easily produce certain highly toxic intermediates.Therefore,this article designs a dual template ...The microbial degradation of aromatic organic pollutants is incomplete due to their metabolic characteristics,which can easily produce certain highly toxic intermediates.Therefore,this article designs a dual template molec-ularly imprinted sensor(DTMIP/Fe-Mn@C)for iron manganese metal nanomaterials,prepared Fe-Mn@C com-posite materials by a one pot method were coated on the surface of glassy carbon electrodes and covered with molecularly imprinted membranes through electropolymerization and elution methods,achieving real-time de-tection of specific intermediate products 2-methylbutyric acid(2-MBA)and 3-methylbutyric acid(3-MBA)de-graded by azo dyes.In order to determine the detection sensitivity and intensity range of the sensor,optimization experiments were conducted on various parameters that affect the detection performance,such as the type of func-tional monomer and its composition ratio with the template molecule,detection time window,environmental pH value,etc.Finally,o-Phenylenediamine was determined as the functional monomer,with a molar ratio of 1:1:6 to the template molecules 2-MBA and 3-MBA.Electrochemical testing was conducted in a neutral environment with an incubation time of 5 min and pH=7.The results indicate that the sensor has a relatively wide detection range,high sensitivity,obvious recognition features,and excellent stability for 2-MBA and 3-MBA.This new dual template molecularly imprinted sensor can quickly and accurately determine the safety of highly toxic interme-diates in the degradation process of aromatic organic pollutants,providing a theoretical basis and application potential for trace detection and real-time monitoring.展开更多
The limited high-temperature oxidation resistance of Mg alloys is a key factor restricting their development and application.The addition of some rare earth elements(REs),owing to their unique physical and chemical pr...The limited high-temperature oxidation resistance of Mg alloys is a key factor restricting their development and application.The addition of some rare earth elements(REs),owing to their unique physical and chemical properties,can significantly enhance the oxidation resistance of Mg alloys.Based on our previous study,we conclude that REs such as Gd,Y,and Ce enhance the oxidation resistance of Mg-RE alloys.This article comprehensively reviews recent research progress on high-temperature oxidation behavior and the potential mechanism in Mg-RE alloys.Based on the thermodynamic and kinetic analyses,the evolution of the complex oxide system formed during the high-temperature oxidation of Mg-RE alloys is first summarized.The diffusion behavior and concentration control mechanisms of REs during the oxidation process and how these mechanisms affect the sustained growth of the oxide film and antioxidant properties were elucidated.Moreover,the different structures of the oxide films were classified,and their properties were discussed.Finally,this paper introduces the applications of commonly used REs in Mg alloys and frontier research on their oxidation mechanisms.Based on the above review,we propose that future research perspectives can be explored in terms of expanding the experimental temperature range for oxidation tests,optimizing the chemical composition by adding trace REs to study their synergistic mechanism,revealing the underlying oxidation mechanism through advanced in situ microscopic characterization methods,and investigating the mechanical properties of oxide films using diverse approaches.展开更多
While nuclear energy represents a low-carbon and high-efficiency energy source that plays a vital role in the global energy mix,the limitations of spent fuel reprocessing technology pose a major challenge to its susta...While nuclear energy represents a low-carbon and high-efficiency energy source that plays a vital role in the global energy mix,the limitations of spent fuel reprocessing technology pose a major challenge to its sustainable development.The PUREX(plutonium uranium redox extraction)process is currently the dominant nuclear fuel reprocessing technology in the world.However,the key extractant in this process is tributyl phosphate(TBP),which degrades under intense radiation,high temperatures,and strong acidity.This leads to the production of dibutyl phosphate,monobutyl phosphate,and other degradation byproducts,which may reduce the extraction efficiency and trigger third-phase formation and equipment corrosion.This paper systematically reviews the degradation mechanisms of TBP and its diluents,the analytical technique suitable for characterizing degradation products,and the impact of degradation products on the post-treatment process.Additionally,optimization strategies employed for suppressing third-phase formation are discussed.This study offers a theoretical foundation and technical insights in optimizing the PUREX process and ensuring the safe operation of the post-treatment process.展开更多
To elucidate the accelerated degradation mechanisms of metallic interconnects in operational solid oxide fuel cells,the oxidation behavior of FSS430 ferritic stainless steel under the coupling of simultaneous electric...To elucidate the accelerated degradation mechanisms of metallic interconnects in operational solid oxide fuel cells,the oxidation behavior of FSS430 ferritic stainless steel under the coupling of simultaneous electrical current and high-temperature exposure is investigated.Isothermal thermogravimetric analysis was employed to quantify oxidation kinetics,complemented by microstructural characterization using X-ray diffraction,scanning electron microscopy with energy-dispersive spectroscopy and transmission electron microscopy.Experimental results demonstrate that the applied current dramatically enhances oxidation rates,increasing specific mass gain from 0.25 mg/cm^(2)(0 A/cm^(2))to 5.20 mg/cm^(2)(0.2 A/cm^(2))and oxide scale thickness from 1.87 to 15.62μm after 200 h.This acceleration originates from current-induced electromigration forces that promote cationic transport through the oxide layer.The quantitative relationships between current density and oxidation parameters are established,enabling predictive modeling of interconnector degradation in solid oxide fuel cell(SOFC)systems.展开更多
Platinum group metals have high melting points,strong corrosion resistance,stable chemical properties,and low oxygen permeability in high-temperature oxygen-containing environments.As thermal protective coating materi...Platinum group metals have high melting points,strong corrosion resistance,stable chemical properties,and low oxygen permeability in high-temperature oxygen-containing environments.As thermal protective coating materials,they have gained essential applications in the aerospace field and have excellent prospects for application in frontier military fields,such as protecting hot-end components of hypersonic aircraft.This research reviewed the latest research progress of platinum group metal coatings with hightemperature oxidation resistance,including coating preparation techniques,oxidation failure,and alloying modification.The leading preparation techniques of current platinum group metal coatings were discussed,as well as the advantages and disadvantages of various existing preparation techniques.Besides,the intrinsic properties,failure forms,and failure mechanisms of coatings of single platinum group metal in high-temperature oxygen-containing environments were analyzed.On this basis,the necessity,main methods,and main achievements of alloying modification of platinum group metals were summarized.Finally,the future development of platinum group coatings with high-temperature oxidation resistance was discussed and prospected.展开更多
To overcome the limitations of traditional photocatalysts,such as inefficient separation of charge carriers and poor visible-light absorption,S-scheme g-C_(3)N_(4)/TiO_(2) heterojunction photocatalysts were synthesize...To overcome the limitations of traditional photocatalysts,such as inefficient separation of charge carriers and poor visible-light absorption,S-scheme g-C_(3)N_(4)/TiO_(2) heterojunction photocatalysts were synthesized via a combined method of thermal polymerization,hydrothermal synthesis,and calcination.The crystal structures,morphological features,and optical properties of the composites were systematically characterized,and their photocatalytic performance was evaluated through tetracycline(TC)degradation and hydrogen evolution experiments.Trapping experiments and electron paramagnetic resonance(EPR)measurements were conducted to elucidate the reaction mechanisms.The results demonstrate that the S-scheme heterojunction effectively extends the visible-light absorption range and facilitates the efficient separation of photogenerated electron-hole pairs.Under optimal conditions,the composite achieved a TC degradation rate of 94.5%and a hydrogen evolution rate of 329.1μmol·h^(-1)·g^(-1) after 8 h of irradiation,both values being significantly higher than those of pristine g-C_(3)N_(4) or TiO_(2).Moreover,the S-scheme g-C_(3)N_(4)/TiO_(2) heterojunction retained high photocatalytic activity over five consecutive cycles,confirming its excellent stability.Mechanistic investigations revealed that the S-scheme heterojunction maintained strong redox capacities,with superoxide radicals(·O_(2)^(-)),hydroxyl radicals(·OH),electrons(e-),and holes(h+)serving as the primary active species responsible for TC degradation and H2 production.展开更多
Ethylene(C_(2)H_(4))in vehicle exhaust is a highly reactive volatile organic compound(VOC).Its photooxidative reaction with NOx contributes to the formation of O3 and secondary organic aerosols(SOA),the latter being a...Ethylene(C_(2)H_(4))in vehicle exhaust is a highly reactive volatile organic compound(VOC).Its photooxidative reaction with NOx contributes to the formation of O3 and secondary organic aerosols(SOA),the latter being a key precursor of PM_(2.5).In this study,a novel MgO-supported Ag-Cu bimetallic catalyst was designed and investigated using density functional theory(DFT).The effects of Ag and Cu loading on the geometric structure,stability,and reactant adsorption characteristics of the catalyst were analyzed,and the catalytic oxidation pathways of C_(2)H_(4)over AgCu-MgO was elucidated.The results indicate that loading Ag significantly enhances the adsorption of C_(2)H_(4).The incorporation of Cu into Ag-MgO to form a AgCu-MgO bimetallic catalyst(dual atom catalyst,DACS)further improves the oxidative activity toward C_(2)H_(4).Based on the binding energies of the Ag and Cu bimetallic sites and the adsorption energies of C_(2)H_(4)and O_(2),three representative configurations were selected for detailed reaction pathway analysis.Among them,Configuration 6 of AgCu-MgO exhibited the highest catalytic oxidation performance.This study provides new atomic-scale insights for the rational design of efficient catalysts targeting olefinic pollutants in automotive emissions and offers valuable guidance for advancing exhaust after-treatment technologies.展开更多
Perovskite oxides are highly promising catalysts for the combustion removal of volatile organic compounds(VOCs)due to their excellent stability,structural flexibility,and compositional versatility.This study presents ...Perovskite oxides are highly promising catalysts for the combustion removal of volatile organic compounds(VOCs)due to their excellent stability,structural flexibility,and compositional versatility.This study presents a novel perovskite oxide that exhibits enhanced catalytic activity and superior durability for toluene combustion at reduced temperatures.This improvement is achieved by phosphorus doping at the B-site of LaCoO_(3-δ)(LC)perovskite oxide,followed by post-synthesis acid etching for a proper time.The resulting catalyst demonstrates increased specific surface area,higher total pore volume,and enhanced oxygen vacancy concentration both in the bulk and on the surface.Additionally,the activity of surface lattice oxygen species is significantly improved,leading to enhanced catalytic performance in toluene combustion.Notably,the optimized catalyst shows an exceptionally low activation energy(E_(a))of 49.3 kJ mol^(-1),with a T90 reduction of over 214℃compared to the phosphorus doped LC and 190℃compared to pristine LC.Phosphorus doping plays a main role in significantly improving the long-term durability,particularly in the presence of CO_(2)and H_(2)O,while acid etching boosts the catalytic activity.This work introduces a rational and innovative strategy for optimizing VOC oxidation by improving the structure and surface chemical states of perovskite catalysts.展开更多
Severe internal oxidation formed in advanced high-strength steels(AHSSs)during the hot-rolled coiling process compromises subsequent cold rolling and galvanizing processes.Herein,we report how Sn microalloying governs...Severe internal oxidation formed in advanced high-strength steels(AHSSs)during the hot-rolled coiling process compromises subsequent cold rolling and galvanizing processes.Herein,we report how Sn microalloying governs internal oxidation behavior and modulates iron oxide phase transition process.Sn addition significantly reduces the depth of grain boundaries oxidation and the area of internal oxidation,as well as retards the process of oxide scale transformation.Sn preferentially segregates at the iron oxide/substrate interface,forming a diffusion barrier that suppresses outward diffusion of alloying elements and inward oxygen transport.Concurrently,Sn enrichment at grain boundaries obstructs short-circuit oxygen diffusion pathways,significantly reducing the depth of oxidation at the grain boundaries.Furthermore,Sn segregation decreases the interfacial oxygen chemical potential and oxygen availability for selective oxidation reaction.The strategic incorporation of surface-active elements has emerged as a viable metallurgical approach to reduce internal oxidation in hot-rolled coils for AHSS applications.展开更多
基金supported by the National Natural Science Foundation of China(Nos.42477406 and 51878617)the Horizontal Scientific Research Project(No.KYY-HX-20220803)the Engineering Research Center of Ministry of Education for Renewable Energy Infrastructure Construction Technology.
文摘In this work,we constructed a three-dimensional electrochemical system(3D-ECO),which included the cathode and anode electrode plates,as well as the screening of three-dimensional particle electrodes and parameter opti-mization,for the degradation of landfill leachate(LL)containing elevated levels of tetracycline(TC),and explored its mechanism of action.Firstly,titanium-based ruthenium-iridium(Ti/RuO_(2)-IrO_(2)),titanium-based ruthenium-iridium-platinum(Ti/Pt-RuO_(2)-IrO_(2)),and titanium-based tin-antimony(Ti/SnO_(2)-Sb_(2)O_(3))were employed as an-odes in the electrocatalytic oxidation system,with titanium and stainless steel plates serving as cathodes,to construct the optimal two-dimensional electrocatalytic oxidation system(2D-ECO)through cross-comparison ex-periments.Subsequently,using granular activated carbon(GAC),coconut shell biochar(CBC),walnut shell carbon(WBC),and bamboo charcoal(BBC)as particle electrodes,a 3D-ECO system was developed.The influence of var-ious operational parameters on treating TC-containing LL was investigated.The optimal operating parameters obtained from the study was:pH=5,current density of 30 mA/cm^(2),particle dosage of 7 g/L,particle size ranging from 1.70 to 2.00 mm,and electrode spacing of 4 cm.Under these conditions,the COD removal rate of 3D-ECO within three hours was 90.25%,the TC removal rate was 72.41%,and the NH_(3)-N removal rate was 39.52%.The removal of TC followed a pseudo-first-order kinetic model.Additionally,degradation mechanisms were elucidated through electron paramagnetic resonance(EPR)spectrometer and Tert-Butanol(TBA)quenching experiments,indicating that the degradation primarily occurred through a non-radical(1O_(2))pathway.This re-search offers a comprehensive analysis of the simultaneous breakdown of intricate LL matrices and TC,enhancing our comprehension of the degradation processes and underlying mechanisms.
基金Motor Neuron Disease Research Australia in the form of a Bill Gole Postdoctoral Fellowship(PDF2307)FightMND in the form of Drug Development Grants(DDG-159 and DDG137 to JSL)。
文摘Superoxide dismutase 1(SOD1)is a thermodynamically stable,zinc and copper binding homodimeric enzyme responsible for breaking down superoxide radicals.More than 200,mostly missense,mutations spread throughout the SOD1 gene are associated with the fatal neurodegenerative disease,amyotrophic lateral sclerosis(ALS).A unifying feature of ALS-associated SOD1 mutations is the destabilization of the SOD1 protein structure,increasing the propensity for misfolding and subsequent pathological aggregation.Post-mortem analysis of SOD1-associated ALS tissue shows the accumulation of misfolded SOD1 protein and ubiquitinated SOD1 inclusions within motor neurons.Misfolded SOD1 accumulation and aggregates are implicated in cellular dysfunction via a number of disparate but critical processes,including endoplasmic reticulum stress,oxidative damage,proteasome dysfunction,axonal transport abnormalities and synaptic dysfunction;culminating in motor neuron degeneration associated with ALS.
基金financially supported by the National Key Technology R&D Program of China(No.2021YFB3500801)
文摘Enhancing the activity of photocatalysts is a critical challenge for improving the photocatalytic degradation of contaminated wastewater.Here,a novel Ce single-atom-doped titanate nanotube photocatalyst(CeH_(2)Ti_(2)O_(5)·H_(2)O)was successfully synthesized using a onepot solvothermal method.Degradation experiments revealed that the optimal Ce doping ratio was 1.0%.The ultraviolet-visible diffuse reflectance spectroscopy results showed that the bandgap of the Ce-doped sample decreased from 3.02 to 2.87 eV,enhancing the absorption in the visible spectral range.At the same time,the BrunauerEmmett-Teller specific surface area increased from 63.68 to 88.95 m^(2)g^(-1).The 1.0%Ce-H_(2)Ti_(2)O_(5)·H_(2)O(HTC_(1))could degrade 99.04%of 100 mg L-1rhodamine B(RhB)after 40 min of visible-light irradiation.The degradation efficiency decreased by only 21.24%after five cycles.The results of free-radical quenching and electron spin resonance spectroscopy analyses indicated that HTC_(1)achieved efficient degradation of RhB through a direct hole oxidation mechanism.Compared with pure protonated titanate nanotubes(H_(2)Ti_(2)O_(5)·H_(2)O),HTC_(1)had a higher specific surface area,more electron traps,narrower bandgap,longer hole lifetime,and suppressed photogenerated charge recombination rate owing to the Ce single-atom doping.
基金supported by the National Natural Science Foundation of China(22288102)。
文摘The large molecular weight and high hydrophilicity of chloramphenicol(CAP) residuals in wastewater led to severe degradation difficulty,which propelled the development of new wastewater degradation processes and reactors based on process intensification.This study enhanced the CAP degradation by ozone/peroxydisulfate(PDS) advanced oxidation process in a submerged rotating packed bed(SRPB)reactor.Compared the usage of different oxidants,it was indicated that the combination of O_(3) and PDS exhibited a higher degradation efficiency than ozone and PDS alone.The more desired degradation efficiency could be achieved at the operating conditions of ascending PDS concentration,SRPB rotational speed,ozone concentration,reduced initial CAP concentration,and the water qualities of ascended pH,lower Cl^(-)and initial CO_(3)^(2-) concentrations.Under the optimized conditions of C_(CAP)=20 mg·L^(-1),C_(O3)=30 mg·L^(-1),C_(PDS)=100 mg·L^(-1),and N=400 r·min^(-1),and water qualities of pH=10,the maximum chloramphenicol degradation efficiency of 97% and kinetic constant of 0.23 min^(-1) were achieved after treating 16 min.A comparison of the results with previously reported advanced oxidation processes of CAP indicated that the enhanced O^(3)/PDS advanced oxidation system using the SRPB can significantly improve the degradation efficiency of CAP.
基金supported by the Natural Science Foundation of Inner Mongolia Autonomous Region of China(Grant No.2024LHMS05048).
文摘Addressing the growing challenge of water contamination,this study comparatively evaluated a persulfate(PDS)system activated by nonradical nitrogen-doped carbon nanotubes(N-CNTs)versus a PDS system activated by radical-based iron(Fe^(2+)),both used for the degradation of bisphenol A(BPA).The N-CNTs/PDS system,driven by the electron transfer mechanism,achieved remarkable 90.9%BPA removal within 30 min at high BPA concentrations,significantly outperforming the Fe^(2+)/PDS system,which attained only 38.9%removal.The N-CNTs/PDS system maintained robust degradation efficiency across a wide range of BPA concentrations and exhibited a high degree of resilience in diverse water matrices.By directly abstracting electrons from BPA molecules,the N-CNTs/PDS system effectively minimised oxidant wastage and mitigated the risk of secondary pollution,ensuring efficient utilisation of active sites on N-CNTs and sustaining a high catalytic rate.The formation of the N-CNTs-PDS^(*)complex significantly enhanced BPA degradation and mineralisation,thereby optimising PDS consumption.These findings highlight the unparalleled advantages of the N-CNTs/PDS system in managing complex wastewater,offering a promising and innovative solution for treating complex industrial wastewater and advancing environmental remediation efforts.
基金supported by the Fundamental Research Funds for the Central Universities(Nos.KYCYXT2023001,and XUEKEN2022034).
文摘Currently,ferrate(VI)oxidation technology(FOT)has been regarded as one of the most promising options for the degradation of emerging organic pollutants.However,the role and transformation of chloride ions(Cl^(−))in FOT have not been well explored.The current study aims to investigate the formation of chlorinated phenolic byproducts upon ferrate(VI)oxidation processes.The obtained results indicate that chlorides suffering ferrate(VI)attack will be transformed to active chlorine species(ACS),which will subsequently lead to the formation of highly toxic aromatic chlorinated byproducts.The identified byproducts include common chlorinated phenolic derivatives,as well as complex chlorinated oligomer byproducts with ether structures(mainly dimers and trimers).While the formation of common chlorophenols can be ascribed to the electrophilic substitution reactions mediated by ACS,the oligomer byproducts are generated via coupling reactions between chlorinated phenoxy radicals.ECOSAR software predicts that the generated chlorinated oligomer byproducts exhibit high ecotoxicological effects.As a whole,the above findings shed light on the potential risk of FOT in real practice.
基金The Key Project of Chinese Ministry of Education (No.108601)Major Projects of National Water Pollution Control and Management Technology (No.2009ZX07101-011)Specialized Research Fund for the Doctoral Program of Higher Education (No.20060286010)
文摘Boron-doped diamond （BDD） electrocatalysis is combined with photocatalysis using titanium dioxide （TiO2） as a catalyst to improve pollutant-oxidation efficiency. Phenol solution is chosen as model wastewater. Different methods involving BDD and/or TiO2 during the degradation processes are compared. Parameters such as the currency density and initial concentration are varied in order to determine their effects on the oxidation process. Moreover, the degradation kinetics of phenol is experimentally studied. The results reveal the superiority of series combination of BDD and TiO2, especially the treatment process of electrocatalysis and succedent photocatalysis, and the optimum working currency density for electrocatalysis is 25.48 mA/cm2. The removal rate decreases with the increase in the initial phenol concentration and the degradation reaction follows quasi-first-order kinetics equation.
基金National Natural Science Foundation of China(52071274)Key Research and Development Projects of Shaanxi Province(2023-YBGY-442)Science and Technology Nova Project-Innovative Talent Promotion Program of Shaanxi Province(2020KJXX-062)。
文摘To mitigate the impact of interdiffusion reactions between the silicide slurry and Ta12W alloy substrate during vacuum sintering process on the oxidation resistance of the silicide coating,a micro-arc oxidation pretreatment was employed to construct a Ta_(2)O_(5)ceramic layer on the Ta12W alloy surface.Subsequently,a slurry spraying-vacuum sintering method was used to prepare a Si-Cr-Ti-Zr coating on the pretreated substrate.Comparative studies were conducted on the microstructure,phase composition,and isothermal oxidation resistance(at 1600℃)of the as-prepared coatings with and without the micro-arc oxidation ceramic layer.The results show that the Ta_(2)O_(5)layer prepared at 400 V is more continuous and has smaller pores than that prepared at 350 V.After microarc oxidation pretreatment,the Si-Cr-Ti-Zr coating on Ta12W alloy consists of three distinct layers:an upper layer dominated by Ti_(5)Si_(3),Ta_(5)Si_(3),and ZrSi;a middle layer dominated by TaSi_(2);a coating/substrate interfacial reaction layer dominated by Ta_(5)Si_(3).Both the Si-Cr-Ti-Zr coatings with and without the Ta_(2)O_(5)ceramic layer do not fail after isothermal oxidation at 1600℃for 5 h.Notably,the addition of the Ta2O5 ceramic layer reduces the high-temperature oxidation rate of the coating.
基金National Natural Science Foundation of China(Nos.42177405,42377359,12075152)Energy Science and Technology discipline under the Shanghai Class IV Peak Disciplinary Development Program for the financial support.W.Y.Huang thanks the China Scholarship Council(CSC)for funding.
文摘Antibiotics are emerging pollutants that pose significant risks to environmental and human health.Periodate(PI)-based advanced oxidation processes have shown promise for their effective degradation.In this study,we systematically investigate the structure-activity relationship of four representative Fe-based metal-organic frameworks(Fe-MOFs)-MIL-101(Fe),MIL-88B(Fe),MIL-88A(Fe),and MIL-53(Fe)-as PI activators for tetracycline(TC)degradation.Among them,MIL-101(Fe)exhibited the highest catalytic performance,owing to its unique Fe3O-OH nodes and mesoporous architecture.The MIL-101(Fe)/PI system achieved 93.3%TC degradation and 55.9%mineralization rate within 60 min.Mechanistic studies combining scavenger quenching,sulfoxide probe transformation,X-ray photoelectron spectroscopy,and X-ray absorption fine structure confirmed the generation of multiple reactive oxygen species,and high-valent Fe(IV)]O and O_(2)^(·-)played major roles in the tetracycline degradation process.Density functional theory calculations further revealed that MIL-101(Fe)and MIL-88B(Fe)effectively interact with PI to form Fe(Ⅲ)-superoxide(Fe(Ⅲ)-O-O^(·-)),a key intermediate in Fe(IV)]O generation.In contrast,the adsorption energy of MIL-53(Fe)and MIL-88A(Fe)was relatively weak,with fewer binding sites,resulting in poor performance.The synergy between Fe(Ⅲ)-O-O^(·-)formation and the pore accessibility of MIL-101(Fe)accounted for its superior catalytic efficiency.This work not only clarifies the structural factors governing PI activation in Fe-MOFs,but also proposes a mechanistically informed strategy for designing high-performance catalysts for antibiotic degradation.
文摘In this study,sawdust served as a carbon source and urea as a nitrogen source to synthesize carbonsupported,nitrogen-doped TiO_(2)composites via a one-pot solvothermal method.The composites were characterized using FTIR,powder X-ray diffraction,X-ray photoelectron spectroscopy,ultraviolet-visible diffuse reflectance spectroscopy,thermogravimetry-derivative thermogravimetry,scanning electron microscopy-energy dispersive spectroscopy,and transmission electron microscopy.Results indicated that all synthesized composites exhibit the anatase phase,with those calcined at 800℃ demonstrating enhanced crystallinity.Nitrogen is incorporated into the TiO_(2)lattice,while carbon is predominantly located on the surface.Photodegradation experiments showed that 20 mg of composite N-TiO_(2)/C-800 achieved degradation rates of 93.4% for methylene blue(20 mg·L^(-1),50 mL)and 99.4% for oxytetracycline(20 mg·L^(-1),50 mL)within 30 min.Free radical capture experiments indicated that h+was the primary active species in the photocatalytic degradation process.
基金National Natural Science Foundation of China(52272075,52472053)Research Fund of Youth Innovation Promotion Association of CAS,China(2021190)Defense Industrial Technology Development Program(JCKY2021130B007)。
文摘Carbon fiber-reinforced carbon aerogel(C/CA)composites are one of the most promising candidates for applications requiring both thermal insulation and load bearing capabilities.The preparation of anti-oxidation coatings on C/CA to address its susceptibility to oxidation is a feasible approach to promote its application in oxidative environments.However,the currently reported coatings on C/CA mainly focus on improving the ablation performance and coating preparation process typically necessitating high-temperature heat treatment.This procedure can increase its thermal conductivity and reduce its thermal insulation ability.In this study,a series of ceramic-resin coatings were fabricated on C/CA through a simple slurry brushing-drying approach at room temperature.The effects of phenolic resin content on the coating structure,residual stress,thermal shock,and oxidation behaviors were investigated.Due to the adhesive properties and curing-induced shrinkage,the PR-7.5 coating(containing 7.5%(in mass)phenolic resin in the slurry)exhibits bonding strength close to fracture strength of the substrate and residual compressive stress of 0.853 GPa,which is beneficial for resisting thermal shock cracking.However,excessive resin content(PR-10.0 containing 10.0%(in mass)phenolic resin in the slurry)induces tensile stress due to uneven curing shrinkage,thereby leading to thermal shock cracking.Meanwhile,oxidation tests reveal significantly reduced weight losses for PR-7.5(17.46%at 800℃/100 min,8.15%at 1000℃/120 min,3.15%at 1200℃/120 min)versus uncoated C/CA’s 44.60%loss at 800℃/20 min.This work provides a brand-new and simple approach to improving the anti-oxidation performance of C/CA and expands its application in mild oxidative environments.
基金supported by the Bingtuan Industrial Technology Research Institute,Bingtuan New materials Research Institute innovation platform project,Research initiation project of Shihezi University(No.RCZK202330)the Science and Technology Program-Regional Innovation Guidance Program(No.2023ZD080)Tianchi Talent Project(No.CZ002735).
文摘The microbial degradation of aromatic organic pollutants is incomplete due to their metabolic characteristics,which can easily produce certain highly toxic intermediates.Therefore,this article designs a dual template molec-ularly imprinted sensor(DTMIP/Fe-Mn@C)for iron manganese metal nanomaterials,prepared Fe-Mn@C com-posite materials by a one pot method were coated on the surface of glassy carbon electrodes and covered with molecularly imprinted membranes through electropolymerization and elution methods,achieving real-time de-tection of specific intermediate products 2-methylbutyric acid(2-MBA)and 3-methylbutyric acid(3-MBA)de-graded by azo dyes.In order to determine the detection sensitivity and intensity range of the sensor,optimization experiments were conducted on various parameters that affect the detection performance,such as the type of func-tional monomer and its composition ratio with the template molecule,detection time window,environmental pH value,etc.Finally,o-Phenylenediamine was determined as the functional monomer,with a molar ratio of 1:1:6 to the template molecules 2-MBA and 3-MBA.Electrochemical testing was conducted in a neutral environment with an incubation time of 5 min and pH=7.The results indicate that the sensor has a relatively wide detection range,high sensitivity,obvious recognition features,and excellent stability for 2-MBA and 3-MBA.This new dual template molecularly imprinted sensor can quickly and accurately determine the safety of highly toxic interme-diates in the degradation process of aromatic organic pollutants,providing a theoretical basis and application potential for trace detection and real-time monitoring.
基金supported by the Key R&D Program of Shandong Province,China(No.2025CXGC 010412)the National Key Research and Development Program of China(No.2022YFB3709300)the National Natural Science Foundation of China(No.U21A2048).
文摘The limited high-temperature oxidation resistance of Mg alloys is a key factor restricting their development and application.The addition of some rare earth elements(REs),owing to their unique physical and chemical properties,can significantly enhance the oxidation resistance of Mg alloys.Based on our previous study,we conclude that REs such as Gd,Y,and Ce enhance the oxidation resistance of Mg-RE alloys.This article comprehensively reviews recent research progress on high-temperature oxidation behavior and the potential mechanism in Mg-RE alloys.Based on the thermodynamic and kinetic analyses,the evolution of the complex oxide system formed during the high-temperature oxidation of Mg-RE alloys is first summarized.The diffusion behavior and concentration control mechanisms of REs during the oxidation process and how these mechanisms affect the sustained growth of the oxide film and antioxidant properties were elucidated.Moreover,the different structures of the oxide films were classified,and their properties were discussed.Finally,this paper introduces the applications of commonly used REs in Mg alloys and frontier research on their oxidation mechanisms.Based on the above review,we propose that future research perspectives can be explored in terms of expanding the experimental temperature range for oxidation tests,optimizing the chemical composition by adding trace REs to study their synergistic mechanism,revealing the underlying oxidation mechanism through advanced in situ microscopic characterization methods,and investigating the mechanical properties of oxide films using diverse approaches.
基金supported by the Youth Talent Project of China Nuclear Power Engineering Co.,Ltd.(KY24045).
文摘While nuclear energy represents a low-carbon and high-efficiency energy source that plays a vital role in the global energy mix,the limitations of spent fuel reprocessing technology pose a major challenge to its sustainable development.The PUREX(plutonium uranium redox extraction)process is currently the dominant nuclear fuel reprocessing technology in the world.However,the key extractant in this process is tributyl phosphate(TBP),which degrades under intense radiation,high temperatures,and strong acidity.This leads to the production of dibutyl phosphate,monobutyl phosphate,and other degradation byproducts,which may reduce the extraction efficiency and trigger third-phase formation and equipment corrosion.This paper systematically reviews the degradation mechanisms of TBP and its diluents,the analytical technique suitable for characterizing degradation products,and the impact of degradation products on the post-treatment process.Additionally,optimization strategies employed for suppressing third-phase formation are discussed.This study offers a theoretical foundation and technical insights in optimizing the PUREX process and ensuring the safe operation of the post-treatment process.
基金supported by Natural Science Foundation of Wuhan(2024040701010051)Natural Science Foundation of Hubei(2023AFB111)and National Natural Science Foundation of China(52401108).
文摘To elucidate the accelerated degradation mechanisms of metallic interconnects in operational solid oxide fuel cells,the oxidation behavior of FSS430 ferritic stainless steel under the coupling of simultaneous electrical current and high-temperature exposure is investigated.Isothermal thermogravimetric analysis was employed to quantify oxidation kinetics,complemented by microstructural characterization using X-ray diffraction,scanning electron microscopy with energy-dispersive spectroscopy and transmission electron microscopy.Experimental results demonstrate that the applied current dramatically enhances oxidation rates,increasing specific mass gain from 0.25 mg/cm^(2)(0 A/cm^(2))to 5.20 mg/cm^(2)(0.2 A/cm^(2))and oxide scale thickness from 1.87 to 15.62μm after 200 h.This acceleration originates from current-induced electromigration forces that promote cationic transport through the oxide layer.The quantitative relationships between current density and oxidation parameters are established,enabling predictive modeling of interconnector degradation in solid oxide fuel cell(SOFC)systems.
文摘Platinum group metals have high melting points,strong corrosion resistance,stable chemical properties,and low oxygen permeability in high-temperature oxygen-containing environments.As thermal protective coating materials,they have gained essential applications in the aerospace field and have excellent prospects for application in frontier military fields,such as protecting hot-end components of hypersonic aircraft.This research reviewed the latest research progress of platinum group metal coatings with hightemperature oxidation resistance,including coating preparation techniques,oxidation failure,and alloying modification.The leading preparation techniques of current platinum group metal coatings were discussed,as well as the advantages and disadvantages of various existing preparation techniques.Besides,the intrinsic properties,failure forms,and failure mechanisms of coatings of single platinum group metal in high-temperature oxygen-containing environments were analyzed.On this basis,the necessity,main methods,and main achievements of alloying modification of platinum group metals were summarized.Finally,the future development of platinum group coatings with high-temperature oxidation resistance was discussed and prospected.
文摘To overcome the limitations of traditional photocatalysts,such as inefficient separation of charge carriers and poor visible-light absorption,S-scheme g-C_(3)N_(4)/TiO_(2) heterojunction photocatalysts were synthesized via a combined method of thermal polymerization,hydrothermal synthesis,and calcination.The crystal structures,morphological features,and optical properties of the composites were systematically characterized,and their photocatalytic performance was evaluated through tetracycline(TC)degradation and hydrogen evolution experiments.Trapping experiments and electron paramagnetic resonance(EPR)measurements were conducted to elucidate the reaction mechanisms.The results demonstrate that the S-scheme heterojunction effectively extends the visible-light absorption range and facilitates the efficient separation of photogenerated electron-hole pairs.Under optimal conditions,the composite achieved a TC degradation rate of 94.5%and a hydrogen evolution rate of 329.1μmol·h^(-1)·g^(-1) after 8 h of irradiation,both values being significantly higher than those of pristine g-C_(3)N_(4) or TiO_(2).Moreover,the S-scheme g-C_(3)N_(4)/TiO_(2) heterojunction retained high photocatalytic activity over five consecutive cycles,confirming its excellent stability.Mechanistic investigations revealed that the S-scheme heterojunction maintained strong redox capacities,with superoxide radicals(·O_(2)^(-)),hydroxyl radicals(·OH),electrons(e-),and holes(h+)serving as the primary active species responsible for TC degradation and H2 production.
基金Supported by the National Natural Science Foundation of China Project(22362018)the Yunnan Fundamental Research Projects(202401AS070102)。
文摘Ethylene(C_(2)H_(4))in vehicle exhaust is a highly reactive volatile organic compound(VOC).Its photooxidative reaction with NOx contributes to the formation of O3 and secondary organic aerosols(SOA),the latter being a key precursor of PM_(2.5).In this study,a novel MgO-supported Ag-Cu bimetallic catalyst was designed and investigated using density functional theory(DFT).The effects of Ag and Cu loading on the geometric structure,stability,and reactant adsorption characteristics of the catalyst were analyzed,and the catalytic oxidation pathways of C_(2)H_(4)over AgCu-MgO was elucidated.The results indicate that loading Ag significantly enhances the adsorption of C_(2)H_(4).The incorporation of Cu into Ag-MgO to form a AgCu-MgO bimetallic catalyst(dual atom catalyst,DACS)further improves the oxidative activity toward C_(2)H_(4).Based on the binding energies of the Ag and Cu bimetallic sites and the adsorption energies of C_(2)H_(4)and O_(2),three representative configurations were selected for detailed reaction pathway analysis.Among them,Configuration 6 of AgCu-MgO exhibited the highest catalytic oxidation performance.This study provides new atomic-scale insights for the rational design of efficient catalysts targeting olefinic pollutants in automotive emissions and offers valuable guidance for advancing exhaust after-treatment technologies.
基金support from the National Key Research and Development Program of China(Project No.2018YFB1502903).
文摘Perovskite oxides are highly promising catalysts for the combustion removal of volatile organic compounds(VOCs)due to their excellent stability,structural flexibility,and compositional versatility.This study presents a novel perovskite oxide that exhibits enhanced catalytic activity and superior durability for toluene combustion at reduced temperatures.This improvement is achieved by phosphorus doping at the B-site of LaCoO_(3-δ)(LC)perovskite oxide,followed by post-synthesis acid etching for a proper time.The resulting catalyst demonstrates increased specific surface area,higher total pore volume,and enhanced oxygen vacancy concentration both in the bulk and on the surface.Additionally,the activity of surface lattice oxygen species is significantly improved,leading to enhanced catalytic performance in toluene combustion.Notably,the optimized catalyst shows an exceptionally low activation energy(E_(a))of 49.3 kJ mol^(-1),with a T90 reduction of over 214℃compared to the phosphorus doped LC and 190℃compared to pristine LC.Phosphorus doping plays a main role in significantly improving the long-term durability,particularly in the presence of CO_(2)and H_(2)O,while acid etching boosts the catalytic activity.This work introduces a rational and innovative strategy for optimizing VOC oxidation by improving the structure and surface chemical states of perovskite catalysts.
基金National Key Research and Development Program of China(No.2023YFB3712400)Science and Technology Committee of Shanghai(Grant No.21ZR1423600)+2 种基金Central Government Guides the Development of Local Science and Technology Special Fund of China(Grant No.216Z1004G)and Baosteelsupport from Ningbo Yongjiang Talent Introduction Programme(2022A-023-C)Zhejiang Phenomenological Materials Technology Co.,Ltd.,China.Finally,the author Jin thanks Baosteel for permission to publish this work.
文摘Severe internal oxidation formed in advanced high-strength steels(AHSSs)during the hot-rolled coiling process compromises subsequent cold rolling and galvanizing processes.Herein,we report how Sn microalloying governs internal oxidation behavior and modulates iron oxide phase transition process.Sn addition significantly reduces the depth of grain boundaries oxidation and the area of internal oxidation,as well as retards the process of oxide scale transformation.Sn preferentially segregates at the iron oxide/substrate interface,forming a diffusion barrier that suppresses outward diffusion of alloying elements and inward oxygen transport.Concurrently,Sn enrichment at grain boundaries obstructs short-circuit oxygen diffusion pathways,significantly reducing the depth of oxidation at the grain boundaries.Furthermore,Sn segregation decreases the interfacial oxygen chemical potential and oxygen availability for selective oxidation reaction.The strategic incorporation of surface-active elements has emerged as a viable metallurgical approach to reduce internal oxidation in hot-rolled coils for AHSS applications.
