The coupling effect of heat absorption and release exists in the thermal decomposition of a few chemical materials.However,the impact of the above coupling on thermal hazard assessment is not considered in the literat...The coupling effect of heat absorption and release exists in the thermal decomposition of a few chemical materials.However,the impact of the above coupling on thermal hazard assessment is not considered in the literature studies.In this work,nitroguanidine(NQ)and 1,3,5-trinitro-1,3,5-triazine(RDX)are selected as representative materials to explore the influence of the coupling effect on the thermal hazard assessment of chemical materials.The linear heating experiments of NQ and RDX are carried out by a microcalorimeter and synchronous thermal analyser.The thermal decomposition curves are decoupled by advanced thermokinetics software.The thermal decomposition and kinetic parameters before and after decoupling are calculated.The results of TG experiment show that both NQ and RDX began to lose mass during the endothermic stage.The endothermic melting and exothermic decomposition of NQ and RDX are coupled within this stage.The coupling effect has different degrees of influence on its initial decomposition temperature and safety parameters.Compared with the parameters in the coupling state,the initial decomposition temperature and adiabatic induction period after decoupling decrease.The self-accelerating decomposition temperature increases,and internal thermal runaway time decreases.In the thermal hazard assessment of chemical materials with coupling effects,the calculated parameters after decoupling should be taken as an important safety index。展开更多
MgH_(2),TiH_(2),and ZrH_(2) are three typical metal hydrides that have been gradually applied to composite explosives and propellants as additives in recent years.To evaluate ignition sensitivity and explosion severit...MgH_(2),TiH_(2),and ZrH_(2) are three typical metal hydrides that have been gradually applied to composite explosives and propellants as additives in recent years.To evaluate ignition sensitivity and explosion severity,the Hartmann device and spherical pressure vessel were used to test ignition energy and explosion pressure,respectively.The results showed that the ignition sensitivity of ZrH_(2),TiH_(2) and MgH_(2) gradually increased.When the concentration of MgH_(2) is 83.0 g/m^(3) in Hartmann device,the ignition energy attained a minimum of 10.0 mJ.The explosion pressure of MgH_(2) were 1.44 times and 1.76 times that of TiH_(2) and ZrH_(2),respectively,and the explosion pressure rising rate were 3.97 times and 9.96 times that of TiH_(2) and ZrH_(2),respectively,through the spherical pressure vessel.It indicated that the reaction reactivity and reaction rate of MgH_(2) were higher than that of TiH_(2) and ZrH_(2).In addition,to conduct in edepth theoretical analysis of ignition sensitivity and explosion severity,gas production and combustion heat per unit mass of ZrH_(2),TiH_(2) and MgH_(2) were tested by mercury manometer and oxygen bomb calorimetry.The experimental results revealed that MgH_(2) had a relatively high gas production per unit mass(5.15 mL/g),while TiH_(2) and ZrH_(2) both had a gas production of less than 2.0 mL/g.Their thermal stability gradually increased,leading to a gradual increase in ignition energy.Furthermore,compared with theoretical combustion heat,the combustion ratio of MgH_(2),TiH_(2) and ZrH_(2) was more than 96.0%,with combustion heat value of 29.96,20.94 and 12.22 MJ/kg,respectively,which was consistent with the explosion pressure and explosion severity test results.展开更多
In this paper,high cis-1,4 content hydroxyl-terminated polybutadiene(cis-HTPB)with different molecular weights was prepared through the oxidative cracking process using cis-butadiene rubber as raw material.Firstly,thi...In this paper,high cis-1,4 content hydroxyl-terminated polybutadiene(cis-HTPB)with different molecular weights was prepared through the oxidative cracking process using cis-butadiene rubber as raw material.Firstly,this article comprehensively compared the differences between cis-HTPB and conventional I-HTPB in terms of molecular weight distribution,functionality,viscosity,molecular polarity,and other physicochemical properties,which provided effective data support for its subsequent application.In addition,the reaction kinetics study showed that cis-HTPB with isocyanate curing agent has high reactivity,allowing it to be rapidly cured at low temperatures,and the cured elastomers had excellent mechanical properties,with tensile strength and elongation up to 1.89 MPa and 1100%,respectively.It was also found that cis-HTPB has extremely excellent low-temperature resistance,and the glass transition temperature(T_(g))of its cured elastomer is as low as-101℃.Based on the above studies,cis-HTPB is applied as a binder in composite solid propellants for the first time to investigate its practical performance,and the results indicated that cis-HTPB-based propellants have excellent process and mechanical properties.展开更多
Introducing Neutral Polymeric bonding agents(NPBA) into the Nitrate Ester Plasticized Polyether(NEPE)propellant could improve the adhesion between filler/matrix interface, thereby contributing to the development of ne...Introducing Neutral Polymeric bonding agents(NPBA) into the Nitrate Ester Plasticized Polyether(NEPE)propellant could improve the adhesion between filler/matrix interface, thereby contributing to the development of new generations of the NEPE propellant with better mechanical properties. Therefore,understanding the effects of NPBA on the deformation and damage evolution of the NEPE propellant is fundamental to material design and applications. This paper studies the uniaxial tensile and stress relaxation responses of the NEPE propellant with different amounts of NPBA. The damage evolution in terms of interface debonding is further investigated using a cohesive-zone model(CZM). Experimental results show that the initial modulus and strength of the NEPE propellant increase with the increasing amount of NPBA while the elongation decreases. Meanwhile, the relaxation rate slows down and a higher long-term equilibrium modulus is reached. Experimental and numerical analyses indicate that interface debonding and crack propagation along filler-matrix interface are the dominant damage mechanism for the samples with a low amount of NPBA, while damage localization and crack advancement through the matrix are predominant for the ones with a high amount of NPBA. Finally, crosslinking density tests and simulation results also show that the effect of the bonding agent is interfacial rather than due to the overall crosslinking density change of the binder.展开更多
A large amount of propellant materials are produced every year,and storage and disposal of these propellant materials seriously contributes to environmental pollution.Alkyne terminated polybutadiene with urethane segm...A large amount of propellant materials are produced every year,and storage and disposal of these propellant materials seriously contributes to environmental pollution.Alkyne terminated polybutadiene with urethane segments(PUPB)is the macromolecule backbone of these propellant materials,and degradation of PUPB is central to the eco-friendly treatment of propellant materials.In this study,we isolated a polyurethane(PU)-and PUPB-degrading fungus from soils contaminated with rocket propellant,and the fungus H14 was identified as Fusarium solani(Mart.)Sacc.based on macro-and micro-morphology as well as phylogenetic analyses.The ability of F.solani H14 to degrade PU film and PUPB patches was evaluated via mass loss,scanning electron microscopy(SEM)and enzyme production ability.Mass loss analyses revealed a 25.8%reduction in mass of PU and 1.3%reduction in mass of PUPB after F.solani H14 was incubated with PU and PUPB for 90 days,respectively.We found that F.solani H14 mycelia significantly colonized both PU and PUPB.SEM images showed that the surface of PU films and PUPB patches formed holes,underwent folding and experienced damage as well as irregular fissuring from the erosion of fungal hypha.Moreover,two possible degradative enzymes,lipase and esterase,were produced by F.solani.Our study opens a new avenue of research for eco-friendly treatments of explosive materials and propellants.This paper represents the first article on the degradation of PUPB patches.展开更多
Coordination polymerization of renewable β-ocimene has been investigated using asymmetric diiminophosphinate lutetium complex1, β-diketiminate yttrium complex 2, bis(phosphino)carbazolide yttrium complex 3, half-san...Coordination polymerization of renewable β-ocimene has been investigated using asymmetric diiminophosphinate lutetium complex1, β-diketiminate yttrium complex 2, bis(phosphino)carbazolide yttrium complex 3, half-sandwich benzyl fluorenyl scandium complex 4 and pyridyl-methylene-fluorenyl rare-metal complexes 5a–5c. Complexes 1, 4 and 5a–5c show trans-1,2-regioselectivities and high activities, of which 5c exhibits excellent isoselectivity(mmmm>99%). Conversely, complexes 2 and 3 promote β-ocimene polymerization to produce isotactic cis-1,4-polyocimenes(cis-1,4>99%, mm>95%). Diblock copolymers cis-1,4-PIP-block-cis-1,4-POc and cis-1,4-PBD-block-cis-1,4-POc are obtained in one-pot reactions of β-ocimene with isoprene and butadiene using complex 3. Epoxidation and hydroxylation of polyocimene afford functionalized polyolefins with enhanced T_(g)(from-20 ℃ to 79 ℃ and 74 ℃) and hydrophilicity.展开更多
Inspired by hexaazanaphthalene-based conjugated copper metal-organic framework(HATNA-Cu-MOF),we designed 161 HATNA-TM-MOF-based SACs(TM@N_(x)O_(4-x)-HATNA)with varying TM or ligands creating distinct coordination envi...Inspired by hexaazanaphthalene-based conjugated copper metal-organic framework(HATNA-Cu-MOF),we designed 161 HATNA-TM-MOF-based SACs(TM@N_(x)O_(4-x)-HATNA)with varying TM or ligands creating distinct coordination environments(x=0-4)with superior thermodynamic and electrochemical stabilities.Volcano plots can be constructed using(AGOOH^(*)-ΔGO^(*))/ΔGO^(*)as descriptors for oxygen evolution/reduction reaction(OER/ORR)activity,also serving as target parameters for machine learning(ML)models to identify high-performance OER/ORR catalysts.The efficient monofunctional and bifunctional electrocatalysts were successfully predicted,where the ML prediction results well matched the DFT calculation results.We employed Shapley additive explanations(SHAP)for feature analysis and utilized sure independence screening and sparsification operator(SISSO)for generalization.ML analyses reveal that TM-based OER/ORR activities predominantly correlate with three key descriptors:metallic atomic radius,d-orbital electron population,and the heat of formation of the oxide,demonstrating the pivotal role of TM's inherent electronic configuration and physicochemical characteristics in governing electrocatalytic efficacy.The constant-potential approach emphasizes the key role of electric double-layer capacitance in adjusting the kinetic barrier,where changes in the Fermi level influence the occupation of d-orbitals.Variations in electrochemical potential significantly alter the electronic structure of representative Rh@N_(1)O_(3)-HATNA,affecting both the Fermi level and adsorption properties,with the unique 4d^(8)5s^(1)configuration leading to inverted O_(2)adsorption energies as the potential decreases.This study contributes insights into the origin of oxygen evolution-reduction activity for the HATNA-TM-MOF-based SACs and reveals the fundamentals of structure-activity relationships for future applications.展开更多
Carbon-based low-dimensional materials(CLDM)with elemental carbon as the main component have unique physical and chemical properties,and become the focus of research in many fields including energy,environmental prote...Carbon-based low-dimensional materials(CLDM)with elemental carbon as the main component have unique physical and chemical properties,and become the focus of research in many fields including energy,environmental protection,and information technology.Notably,cellulose acetate,the main component of cigarette butts(CBs),is a one-dimensional precursor with a large specific surface area and aspect ratio.Still,their usefulness as building fillers has often been underestimated before.This review summarizes recent advances in CBs recycling and provides suggested guidelines for its use as a CLDM material in renewable energy.Specifically,we first describe the harmful effects of CBs as pollutants in our lives to emphasize the importance of proper recycling.We then summarize previous methods of recycling CBs waste,including clay bricks,asphalt concrete pavement,gypsum,acoustic materials,chemisorption,vector control,and corrosion control.The potential applications of CBs include triboelectric nanogenerator applications,flexible batteries,enhanced metal-organic framework material energy storage devices,and carbon-based hydrogen storage.Finally,the advantages of utilizing CBs-derived CLDM materials over conventional solutions in the energy field are discussed.This review will provide new avenues for solving the intractable problem of CBs and reducing the manufacturing costs of renewable materials.展开更多
Cocrystallization integrates the merits of high energy and insensitivity between energetic molecules to obtain energetics with satisfying performance.However,how to obtain supramolecular synthons accurately and rapidl...Cocrystallization integrates the merits of high energy and insensitivity between energetic molecules to obtain energetics with satisfying performance.However,how to obtain supramolecular synthons accurately and rapidly for predicting the structure and property of cocrystal remains a challenging problem.In this research,an efficient systematic search approach to predict CL-20/2,4-DNI cocrystal has been proposed that 2,4-DNI revolves around CL-20 with a stoichiometric ratio of 1:1 in accordance with the specified rules(hydrogen bond length:2.2-3.0 Å;search radius:6.5 Å;the number of hydrogen bond:1-3).Eight possible supramolecular synthons were obtained by combining quantum chemistry with molecular mechanics.Crystal structure prediction indicated that there are four structures in cocrystal,namely P21/c,P212121,Pbca and Pna21,and CL-20/2,4-DNI cocrystal is likely to be P21/c and the corresponding cell parameters are Z=4,a=8.28 Å,b=12.17 Å,c=20.42 Å,α=90°,β=96.94°,γ=90°,and ρ=1.9353 g/cm^(3).To further study the intermolecular interaction of CL-20/2,4-DNI cocrystal,a series of theoretical analyses were employed including intermolecular interaction energy,electrostatic potential(ESP),Density of State(DOS),Hirshfeld surface analysis.The C-H…O hydrogen bonds are demonstrated as the predominant driving forces in the cocrystal formation.The mechanical properties and detonation properties of CL-20/2,4-DNI cocrystal implies that the cocrystal shows better ductility and excellent detonation performances(9257 m/s,39.27 GPa)and can serve as a promising energetic material.Cocrystal structure predicted was compared with the experimental one to verify the accuracy of systematic search approach.There is a less than 8.8%error between experiment and predict results,indicating the systematic search approach has extremely high reliability and accuracy.The systematic search approach can be a new strategy to search supramolecular synthons and identify structures effectively and does have the potential to promote the development of energetic cocrystal by theoretical design.展开更多
A novel constant-pressure and constant-quenching distance Condensed Combustion Products(CCPs)collection system was developed,coupled with a timing control system,to collect the CCPs formed in the course of burning of ...A novel constant-pressure and constant-quenching distance Condensed Combustion Products(CCPs)collection system was developed,coupled with a timing control system,to collect the CCPs formed in the course of burning of aluminum-based composite propellants.The effects of adiabatic graphite plating,collection zone,quenching distance,time series of collection,and propellant burning rate on the microscopic morphology,particle size distribution and unburned aluminum content of CCPs were investigated.It was verified that the graphite plating can provide a high-fidelity high-temperature environment for propellant combustion.The combustion efficiency is improved by 2.44% compared to the bare propellant case.The time series of collection has a significant effect on the combustion efficiency of aluminum,and the combustion efficiency of aluminum in the thermal state(1.2-2.4 s)is 2.75% higher than that in the cold state(0-1.2 s).Similarly,the characteristics of the CCPs in different collection zones are different.At the quenching distance of 5 mm,the combustion efficiency of aluminum in the core zone(85.39%)is much lower than that in the outer zone(92.07%),while the particle size of the CCPs in the core zone(172μm)is larger than that in the outer zone(41μm).This indicates that the core zone is more likely to produce large-sized and incompletely burned agglomerates during the propellant combustion process.Different burning rates also lead to a significant difference in particle size distribution and combustion efficiency.High burning rates result in higher combustion efficiency.A detailed sequence of the elaborative collection process of CCPs is proposed,mainly including the setting of ignition delay time,burning rate,working pressure,plating length and time series of collection.The findings of this study are expected to provide a reliable tool for the evaluation of the combustion efficiency of solid propellants.展开更多
In order to investigate safety character of solid propellant, the truing process was analyzed by a thermalmechanical coupled finite element method. Based on the viscoelastic integral constitutive relation, the tempera...In order to investigate safety character of solid propellant, the truing process was analyzed by a thermalmechanical coupled finite element method. Based on the viscoelastic integral constitutive relation, the temperature response in truing process was calculated. The result showed that the maximum temperature in solid propellant truing process could attain up to 65 ℃ when the truing velocity was 10 mm/s and the truing thickness was 1 mm, and there was no remarkable temperature change under the truing thickness of 1.0 mm, 1.5 mm and 2.5 mm. The hazard in truing process of solid propellant was mainly close to the edge of cutting area.展开更多
Due to its extremely low electrostatic sensitivity,copper azide primary explosive is greatly limited in practical applications.In this study,a composite film with Cu-MOF in-situ growth on carbon nanofilm was prepared ...Due to its extremely low electrostatic sensitivity,copper azide primary explosive is greatly limited in practical applications.In this study,a composite film with Cu-MOF in-situ growth on carbon nanofilm was prepared by electrospinning and solvothermal methods,and CNF@Cu-N3film with electrostatic safety was obtained by carbonization and azide later.Its electrostatic sensitivity(E50)was greatly increased from 0.05 mJ of raw materials to 4.06 mJ,and still maintained a good detonation performance which could successfully detonate the CL-20 secondary explosive.This is mainly due to the synergistic effect of the carbon film and the MOF structure,which greatly improves the conductivity of the entire system and the uniform distribution of copper particles,providing a new preparation strategy for metal azide film that is suitable for the micro-initiator device.展开更多
In composite solid propellants with high aluminum(Al)content and low burning rate,incomplete combustion of the Al powder may occur.In this study,varying lithium(Li)content in Al-Li alloy powder was utilized instead of...In composite solid propellants with high aluminum(Al)content and low burning rate,incomplete combustion of the Al powder may occur.In this study,varying lithium(Li)content in Al-Li alloy powder was utilized instead of pure aluminum particles to mitigate agglomeration and enhance the combustion efficiency of solid propellants(Combustion efficiency herein refers to the completeness of metallic fuel oxidation,quantified as the ratio of actual-to-theoretical energy released during combustion)with high Al content and low burning rates.The impact of Al-Li alloy with different Li contents on combustion and agglomeration of solid propellant was investigated using explosion heat,combustion heat,differential thermal analysis(DTA),thermos-gravimetric analysis(TG),dynamic high-pressure combustion test,ignition experiment of small solid rocket motor(SRM)tests,condensation combustion product collection,and X-ray diffraction techniques(XRD).Compared with pure Al,Al-Li alloys exhibit higher combustion heat,which contributes to improved combustion efficiency in Al-Li alloy-containing propellants.DTA and TG analyses demonstrated higher reactivity and lower ignition temperatures for Al-Li alloys.High-pressure combustion experiments at 5 MPa showed that Al-Li alloy fuel significantly decreases combustion agglomeration.The results from theφ75 mm andφ165 mm SRM and XRD tests further support this finding.This study provides novel insights into the combustion and agglomeration behaviors of high-Al,low-burning-rate composite solid propellants and supports the potential application of Al-Li alloys in advanced propellant formulations.展开更多
Addressing the degradation of persistent organic pollutants like bisphenol A(BPA)and rhodamine B(RhB)with a photocatalyst that is both cost-effective and environmentally friendly is a notable challenge.This research p...Addressing the degradation of persistent organic pollutants like bisphenol A(BPA)and rhodamine B(RhB)with a photocatalyst that is both cost-effective and environmentally friendly is a notable challenge.This research presents the synthesis of an optimized g-C_(3)N_(4)/Bi_(4)O_(5)Br_(2)composite featuring a Z-scheme heterojunction structure.The precise band alignment of this composite significantly enhances the separation of photogenerated charges and the production of dominant reactive species.The composite demonstrated exceptional photocatalytic performance,with BPA degradation efficiency nearing 98%and RhB achieving complete degradation within 80 and 35 min under visible light,respectively.These results are approximately 1.3 times greater than the individual performance of CN and BOB,surpassing recent literature benchmarks.Through EPR and free radical capture experiments,the role of h^(+)and·O^(2−)as the primary active free radicals in the degradation process have been confirmed.First-principles calculations validated the experimental results,indicating that the Z-type heterojunction is instrumental in generating active species,thus improving degradation efficiency.This study offers a promising strategy for the design of photocatalysts targeting emerging organic pollutants.展开更多
Biosensors are crucial for detecting various analytes relevant to bioanalytical applications.To enhance the specificity and sensitivity of biosensors,bimetallic nanoparticles(BNPs)have been utilized,which demonstrate ...Biosensors are crucial for detecting various analytes relevant to bioanalytical applications.To enhance the specificity and sensitivity of biosensors,bimetallic nanoparticles(BNPs)have been utilized,which demonstrate significant potential for sensing applications owing to their constituent materials’inherent properties,small size,unique architectural features,and biomimetic behavior.Among BNPs,Au-Ag BNPs are promising for sensing applications owing to their small size,high sensitivity,and distinctive characteristics.Herein,we first briefly present the development of Au-Ag BNPs and discuss the fundamentals.Subsequently,we present the relationship between the synthesis method and structure of Au-Ag BNPs.Furthermore,recent advancements in Au-Ag BNPs are highlighted for their role in enhancing biosensors,particularly for electrode modifiers,signal amplifiers,and recognition materials.Finally,we propose several existing challenges and summarize insights pertaining to the potential development of Au-Ag BNPs for biosensing applications.展开更多
It is still a huge challenge to introduce effective crack-healing ability into energetic composites with a high oxidizer content.In this article,a poly(urea-urethane)energetic elastomer was prepared by the polycondens...It is still a huge challenge to introduce effective crack-healing ability into energetic composites with a high oxidizer content.In this article,a poly(urea-urethane)energetic elastomer was prepared by the polycondensation reaction of glycidyl azido polymer(GAP),isophorone diisocyanate(IPDI),and 2-aminophenyl disulfide(2-APD).In the poly(urea-urethane)elastomer structure,the hybrid dynamic lock,including multilevel H-bonds and disulfide bonds,not only provides abundant dynamic interactions and promotes chain diffusion,but also enhances physical crosslinking density.Such a unique design fabricated the energetic elastomer with robust tensile strength(0.72MPa),high stretchability(1631%),and outstanding toughness(8.95MJ/m 3)in the field of energetic polymers.Meanwhile,this energetic elastomer exhibited high self-healing efficiency(98.4%at 60°C)and heat release(Q=1750.46J/g).Experimental and theoretical results adequately explain the self-healing mechanism,particularly the role of azido units.The high-solid content(80wt%)energetic composites based on the energetic elastomer presented outstanding micro-defect self-healing(97.8%)and recycling without loss of mechanical performance.The development of smart energetic composites with excellent self-healing and recyclable ability provides a meaningful way for a wide range of applications in the field of energetic materials.展开更多
Environmental contamination by hexavalent chromium(Cr(VI))and antibiotic drug residues pose significant chal-lenges to public health and ecosystems.This study investigates the application ofCoTiO_(3)/BiVO_(4)@MIL-Fe(5...Environmental contamination by hexavalent chromium(Cr(VI))and antibiotic drug residues pose significant chal-lenges to public health and ecosystems.This study investigates the application ofCoTiO_(3)/BiVO_(4)@MIL-Fe(53)(CT/BV@Fe-MOF)for the reduction of Cr(VI)and degradation of tetracycline(TCL)under visible light.After grafting an iron-based metal–organic framework MIL-Fe(53)on a modified CoTiO_(3)/BiVO_(4)composite,the photogenerated electrons could easily be transferred from CoTiO_(3)to BiVO_(4)/Fe-MOF species via interfacial charge transfer.UV–vis diffuse reflec-tance spectroscopy showed that charge carriers were formed in response to visible light absorption.The effect of different operating parameters,including catalyst load,pH,initial Cr(VI),and TCL concentration,was systematically evaluated during the photocatalytic process.The CT/BV@Fe-MOF composite exhibited 98.7%reduction efficiency in Cr(VI)(50 ppm)and 97.5%degradation efficiency towards TCL(30 ppm)within 90 min,resulting in a greater efficiency than the pristine CoTiO_(3),BiVO_(4),and Fe-MOF materials.The CT/BV@Fe-MOF composite displayed excellent stability over six cycles,highlighting its potential for practical applications.In addition,the plausible degradation pathway of TCL was evaluated using LC-ESI/MS analysis,while the TEST program was utilized to investigate the toxicity of the products generated during the degradation process.展开更多
Devising a desirable nano-heterostructured photoelectrode based on the charge transfer kinetics mechanism is a pivotal strategy for implementing efficient photoelectrocatalytic(PEC)technology,since the charge separati...Devising a desirable nano-heterostructured photoelectrode based on the charge transfer kinetics mechanism is a pivotal strategy for implementing efficient photoelectrocatalytic(PEC)technology,since the charge separation and utilization efficiency of a photoelectrode is critical to its PEC performance.Herein,we fabricate a F–Co_(3)O_(4)@Bi_(2)WO_(6) core–shell hetero-array photoanode by coupling Bi_(2)WO_(6) nanosheets with F–Co_(3)O_(4) nanowires using a simple solvothermal solution method.The three-dimensional hierarchical heterostructure has a homogeneous chemical interface,helping it to promote an S-scheme-based carrier transport kinetics and maintain excellent cycling stability.Charge density difference calculations verify the electron migration trend from F–Co_(3)O_(4) to Bi_(2)WO_(6) upon hybridization and the formation of an internal electric field in the heterojunction,consistent with the S-scheme mechanism,which is identified by in situ irradiation X-ray photoelectron spectroscopy and by ultraviolet photoelectron spectroscopy.The optimized F–Co_(3)O_(4)@Bi_(2)WO_(6)-2 photoelectrode achieves high carrier utilization efficiency and exhibits superior PEC degradation performance for various organic pollutants,including reactive brilliant blue KN-R,rhodamine B,sulfamethoxazole,and bisphenol A.This work not only reveals that F–Co_(3)O_(4)@Bi_(2)WO_(6)-2 is effective for PEC water remediation but also provides a strategy to enhance carrier transport kinetics by designing binary oxides.展开更多
Efficient chemicalwarfare agents(CWAs)detection is required to protect people from the cWAs in war and terrorism.In this work,a Pd-doped SnO_(2)nanoparticles-based gas sensor was developed to detect a nerve agent simu...Efficient chemicalwarfare agents(CWAs)detection is required to protect people from the cWAs in war and terrorism.In this work,a Pd-doped SnO_(2)nanoparticles-based gas sensor was developed to detect a nerve agent simulant named methyl salicylate.The sensing measurements of methyl salicylate under different Pd doping amounts found that the 0.5 at.%Pd-doped SnO_(2)exhibited a significant improvement in the detection of methyl salicylate at the ppb(1ppb=10-9)level,and the response value to 160 ppb methyl salicylate is 0.72 at 250℃.Compared with the pure SnO_(2),the response value is increased by 4.5 times,which could be attributed to the influence of the noble metal Pd on the oxygen state and its catalytic effect.In addition,the 0.5at.%Pd-doped SnO_(2)sensor still has an obvious response to 16ppb methyl salicylate with a response value of 0.13,indicating the lower detection limit of the sensor.展开更多
基金the project of the Open Research Fund Program of Science and Technology on Aerospace Chemical Power Laboratory(Grant No.STACPL320221B04)Key Laboratory of Explosion Science and Technology(Beijing Institute of Technology)The project number is ZDKT21-01.
文摘The coupling effect of heat absorption and release exists in the thermal decomposition of a few chemical materials.However,the impact of the above coupling on thermal hazard assessment is not considered in the literature studies.In this work,nitroguanidine(NQ)and 1,3,5-trinitro-1,3,5-triazine(RDX)are selected as representative materials to explore the influence of the coupling effect on the thermal hazard assessment of chemical materials.The linear heating experiments of NQ and RDX are carried out by a microcalorimeter and synchronous thermal analyser.The thermal decomposition curves are decoupled by advanced thermokinetics software.The thermal decomposition and kinetic parameters before and after decoupling are calculated.The results of TG experiment show that both NQ and RDX began to lose mass during the endothermic stage.The endothermic melting and exothermic decomposition of NQ and RDX are coupled within this stage.The coupling effect has different degrees of influence on its initial decomposition temperature and safety parameters.Compared with the parameters in the coupling state,the initial decomposition temperature and adiabatic induction period after decoupling decrease.The self-accelerating decomposition temperature increases,and internal thermal runaway time decreases.In the thermal hazard assessment of chemical materials with coupling effects,the calculated parameters after decoupling should be taken as an important safety index。
基金This work was greatly supported by the Natural Science Foundation of China(11802272)the Open Research Fund Program of Science and Technology on Aerospace Chemical Power Laboratory(STACPL220181B01).
文摘MgH_(2),TiH_(2),and ZrH_(2) are three typical metal hydrides that have been gradually applied to composite explosives and propellants as additives in recent years.To evaluate ignition sensitivity and explosion severity,the Hartmann device and spherical pressure vessel were used to test ignition energy and explosion pressure,respectively.The results showed that the ignition sensitivity of ZrH_(2),TiH_(2) and MgH_(2) gradually increased.When the concentration of MgH_(2) is 83.0 g/m^(3) in Hartmann device,the ignition energy attained a minimum of 10.0 mJ.The explosion pressure of MgH_(2) were 1.44 times and 1.76 times that of TiH_(2) and ZrH_(2),respectively,and the explosion pressure rising rate were 3.97 times and 9.96 times that of TiH_(2) and ZrH_(2),respectively,through the spherical pressure vessel.It indicated that the reaction reactivity and reaction rate of MgH_(2) were higher than that of TiH_(2) and ZrH_(2).In addition,to conduct in edepth theoretical analysis of ignition sensitivity and explosion severity,gas production and combustion heat per unit mass of ZrH_(2),TiH_(2) and MgH_(2) were tested by mercury manometer and oxygen bomb calorimetry.The experimental results revealed that MgH_(2) had a relatively high gas production per unit mass(5.15 mL/g),while TiH_(2) and ZrH_(2) both had a gas production of less than 2.0 mL/g.Their thermal stability gradually increased,leading to a gradual increase in ignition energy.Furthermore,compared with theoretical combustion heat,the combustion ratio of MgH_(2),TiH_(2) and ZrH_(2) was more than 96.0%,with combustion heat value of 29.96,20.94 and 12.22 MJ/kg,respectively,which was consistent with the explosion pressure and explosion severity test results.
基金the support from the Open Research Fund Program of Science and Technology on Aerospace Chemical Power Laboratory(Grant No.STACPL120221B03)the National Natural Science Foundation of China(Grant No.22175059).
文摘In this paper,high cis-1,4 content hydroxyl-terminated polybutadiene(cis-HTPB)with different molecular weights was prepared through the oxidative cracking process using cis-butadiene rubber as raw material.Firstly,this article comprehensively compared the differences between cis-HTPB and conventional I-HTPB in terms of molecular weight distribution,functionality,viscosity,molecular polarity,and other physicochemical properties,which provided effective data support for its subsequent application.In addition,the reaction kinetics study showed that cis-HTPB with isocyanate curing agent has high reactivity,allowing it to be rapidly cured at low temperatures,and the cured elastomers had excellent mechanical properties,with tensile strength and elongation up to 1.89 MPa and 1100%,respectively.It was also found that cis-HTPB has extremely excellent low-temperature resistance,and the glass transition temperature(T_(g))of its cured elastomer is as low as-101℃.Based on the above studies,cis-HTPB is applied as a binder in composite solid propellants for the first time to investigate its practical performance,and the results indicated that cis-HTPB-based propellants have excellent process and mechanical properties.
基金National Natural Science Foundation of China(U22B20131)for supporting this project.
文摘Introducing Neutral Polymeric bonding agents(NPBA) into the Nitrate Ester Plasticized Polyether(NEPE)propellant could improve the adhesion between filler/matrix interface, thereby contributing to the development of new generations of the NEPE propellant with better mechanical properties. Therefore,understanding the effects of NPBA on the deformation and damage evolution of the NEPE propellant is fundamental to material design and applications. This paper studies the uniaxial tensile and stress relaxation responses of the NEPE propellant with different amounts of NPBA. The damage evolution in terms of interface debonding is further investigated using a cohesive-zone model(CZM). Experimental results show that the initial modulus and strength of the NEPE propellant increase with the increasing amount of NPBA while the elongation decreases. Meanwhile, the relaxation rate slows down and a higher long-term equilibrium modulus is reached. Experimental and numerical analyses indicate that interface debonding and crack propagation along filler-matrix interface are the dominant damage mechanism for the samples with a low amount of NPBA, while damage localization and crack advancement through the matrix are predominant for the ones with a high amount of NPBA. Finally, crosslinking density tests and simulation results also show that the effect of the bonding agent is interfacial rather than due to the overall crosslinking density change of the binder.
基金This work was financed by Open Research Fund Program of Science and Technology on Aerospace Chemical Power Laboratory(STACPL320181B04)We also would like to thank the support from the National Natural Science Foundation of China(NSFC21975066,NSFC21875061).
文摘A large amount of propellant materials are produced every year,and storage and disposal of these propellant materials seriously contributes to environmental pollution.Alkyne terminated polybutadiene with urethane segments(PUPB)is the macromolecule backbone of these propellant materials,and degradation of PUPB is central to the eco-friendly treatment of propellant materials.In this study,we isolated a polyurethane(PU)-and PUPB-degrading fungus from soils contaminated with rocket propellant,and the fungus H14 was identified as Fusarium solani(Mart.)Sacc.based on macro-and micro-morphology as well as phylogenetic analyses.The ability of F.solani H14 to degrade PU film and PUPB patches was evaluated via mass loss,scanning electron microscopy(SEM)and enzyme production ability.Mass loss analyses revealed a 25.8%reduction in mass of PU and 1.3%reduction in mass of PUPB after F.solani H14 was incubated with PU and PUPB for 90 days,respectively.We found that F.solani H14 mycelia significantly colonized both PU and PUPB.SEM images showed that the surface of PU films and PUPB patches formed holes,underwent folding and experienced damage as well as irregular fissuring from the erosion of fungal hypha.Moreover,two possible degradative enzymes,lipase and esterase,were produced by F.solani.Our study opens a new avenue of research for eco-friendly treatments of explosive materials and propellants.This paper represents the first article on the degradation of PUPB patches.
基金financially supported by the open research fund program of Science and Technology on Aerospace Chemical Power Laboratory (No. STACPL120221B03)the National Natural Science Foundation of China (Nos. s22175059,52073275 and U21A20279)。
文摘Coordination polymerization of renewable β-ocimene has been investigated using asymmetric diiminophosphinate lutetium complex1, β-diketiminate yttrium complex 2, bis(phosphino)carbazolide yttrium complex 3, half-sandwich benzyl fluorenyl scandium complex 4 and pyridyl-methylene-fluorenyl rare-metal complexes 5a–5c. Complexes 1, 4 and 5a–5c show trans-1,2-regioselectivities and high activities, of which 5c exhibits excellent isoselectivity(mmmm>99%). Conversely, complexes 2 and 3 promote β-ocimene polymerization to produce isotactic cis-1,4-polyocimenes(cis-1,4>99%, mm>95%). Diblock copolymers cis-1,4-PIP-block-cis-1,4-POc and cis-1,4-PBD-block-cis-1,4-POc are obtained in one-pot reactions of β-ocimene with isoprene and butadiene using complex 3. Epoxidation and hydroxylation of polyocimene afford functionalized polyolefins with enhanced T_(g)(from-20 ℃ to 79 ℃ and 74 ℃) and hydrophilicity.
基金financially supported by the National Natural Science Foundation of China(Nos.62264015 and U2233206)the Civil Aviation Administration of China(No.U1933109)Hubei Province Technology Innovation Program Project(No.2024BCB073)
文摘Inspired by hexaazanaphthalene-based conjugated copper metal-organic framework(HATNA-Cu-MOF),we designed 161 HATNA-TM-MOF-based SACs(TM@N_(x)O_(4-x)-HATNA)with varying TM or ligands creating distinct coordination environments(x=0-4)with superior thermodynamic and electrochemical stabilities.Volcano plots can be constructed using(AGOOH^(*)-ΔGO^(*))/ΔGO^(*)as descriptors for oxygen evolution/reduction reaction(OER/ORR)activity,also serving as target parameters for machine learning(ML)models to identify high-performance OER/ORR catalysts.The efficient monofunctional and bifunctional electrocatalysts were successfully predicted,where the ML prediction results well matched the DFT calculation results.We employed Shapley additive explanations(SHAP)for feature analysis and utilized sure independence screening and sparsification operator(SISSO)for generalization.ML analyses reveal that TM-based OER/ORR activities predominantly correlate with three key descriptors:metallic atomic radius,d-orbital electron population,and the heat of formation of the oxide,demonstrating the pivotal role of TM's inherent electronic configuration and physicochemical characteristics in governing electrocatalytic efficacy.The constant-potential approach emphasizes the key role of electric double-layer capacitance in adjusting the kinetic barrier,where changes in the Fermi level influence the occupation of d-orbitals.Variations in electrochemical potential significantly alter the electronic structure of representative Rh@N_(1)O_(3)-HATNA,affecting both the Fermi level and adsorption properties,with the unique 4d^(8)5s^(1)configuration leading to inverted O_(2)adsorption energies as the potential decreases.This study contributes insights into the origin of oxygen evolution-reduction activity for the HATNA-TM-MOF-based SACs and reveals the fundamentals of structure-activity relationships for future applications.
基金supported by Hubei Province Technology Innovation Program Project(2024BCB073)the National Natural Science Foundation of China(52402249)the China Postdoctoral Science Foundation(2021M690930).
文摘Carbon-based low-dimensional materials(CLDM)with elemental carbon as the main component have unique physical and chemical properties,and become the focus of research in many fields including energy,environmental protection,and information technology.Notably,cellulose acetate,the main component of cigarette butts(CBs),is a one-dimensional precursor with a large specific surface area and aspect ratio.Still,their usefulness as building fillers has often been underestimated before.This review summarizes recent advances in CBs recycling and provides suggested guidelines for its use as a CLDM material in renewable energy.Specifically,we first describe the harmful effects of CBs as pollutants in our lives to emphasize the importance of proper recycling.We then summarize previous methods of recycling CBs waste,including clay bricks,asphalt concrete pavement,gypsum,acoustic materials,chemisorption,vector control,and corrosion control.The potential applications of CBs include triboelectric nanogenerator applications,flexible batteries,enhanced metal-organic framework material energy storage devices,and carbon-based hydrogen storage.Finally,the advantages of utilizing CBs-derived CLDM materials over conventional solutions in the energy field are discussed.This review will provide new avenues for solving the intractable problem of CBs and reducing the manufacturing costs of renewable materials.
基金the support of the National Natural Science Foundation of China(No.22005090)Beijing Institute of Technology Research Fund Program for Young Scholars+2 种基金the National Natural Science Foundation of China(No.11672040 and No.21801016)Open Research Fund Program of Science and Technology on Aerospace Chemical Power Laboratory(STACPL120201B02)the State Key Laboratory of Explosion Science and Technology(No.YB2016-17)。
文摘Cocrystallization integrates the merits of high energy and insensitivity between energetic molecules to obtain energetics with satisfying performance.However,how to obtain supramolecular synthons accurately and rapidly for predicting the structure and property of cocrystal remains a challenging problem.In this research,an efficient systematic search approach to predict CL-20/2,4-DNI cocrystal has been proposed that 2,4-DNI revolves around CL-20 with a stoichiometric ratio of 1:1 in accordance with the specified rules(hydrogen bond length:2.2-3.0 Å;search radius:6.5 Å;the number of hydrogen bond:1-3).Eight possible supramolecular synthons were obtained by combining quantum chemistry with molecular mechanics.Crystal structure prediction indicated that there are four structures in cocrystal,namely P21/c,P212121,Pbca and Pna21,and CL-20/2,4-DNI cocrystal is likely to be P21/c and the corresponding cell parameters are Z=4,a=8.28 Å,b=12.17 Å,c=20.42 Å,α=90°,β=96.94°,γ=90°,and ρ=1.9353 g/cm^(3).To further study the intermolecular interaction of CL-20/2,4-DNI cocrystal,a series of theoretical analyses were employed including intermolecular interaction energy,electrostatic potential(ESP),Density of State(DOS),Hirshfeld surface analysis.The C-H…O hydrogen bonds are demonstrated as the predominant driving forces in the cocrystal formation.The mechanical properties and detonation properties of CL-20/2,4-DNI cocrystal implies that the cocrystal shows better ductility and excellent detonation performances(9257 m/s,39.27 GPa)and can serve as a promising energetic material.Cocrystal structure predicted was compared with the experimental one to verify the accuracy of systematic search approach.There is a less than 8.8%error between experiment and predict results,indicating the systematic search approach has extremely high reliability and accuracy.The systematic search approach can be a new strategy to search supramolecular synthons and identify structures effectively and does have the potential to promote the development of energetic cocrystal by theoretical design.
基金supported by the National Natural Science Foundation of China(Nos.22375164,21975066 and U2241250)the Key Research and Development Program of Shaanxi,China(No.2023KJXX-005)。
文摘A novel constant-pressure and constant-quenching distance Condensed Combustion Products(CCPs)collection system was developed,coupled with a timing control system,to collect the CCPs formed in the course of burning of aluminum-based composite propellants.The effects of adiabatic graphite plating,collection zone,quenching distance,time series of collection,and propellant burning rate on the microscopic morphology,particle size distribution and unburned aluminum content of CCPs were investigated.It was verified that the graphite plating can provide a high-fidelity high-temperature environment for propellant combustion.The combustion efficiency is improved by 2.44% compared to the bare propellant case.The time series of collection has a significant effect on the combustion efficiency of aluminum,and the combustion efficiency of aluminum in the thermal state(1.2-2.4 s)is 2.75% higher than that in the cold state(0-1.2 s).Similarly,the characteristics of the CCPs in different collection zones are different.At the quenching distance of 5 mm,the combustion efficiency of aluminum in the core zone(85.39%)is much lower than that in the outer zone(92.07%),while the particle size of the CCPs in the core zone(172μm)is larger than that in the outer zone(41μm).This indicates that the core zone is more likely to produce large-sized and incompletely burned agglomerates during the propellant combustion process.Different burning rates also lead to a significant difference in particle size distribution and combustion efficiency.High burning rates result in higher combustion efficiency.A detailed sequence of the elaborative collection process of CCPs is proposed,mainly including the setting of ignition delay time,burning rate,working pressure,plating length and time series of collection.The findings of this study are expected to provide a reliable tool for the evaluation of the combustion efficiency of solid propellants.
文摘In order to investigate safety character of solid propellant, the truing process was analyzed by a thermalmechanical coupled finite element method. Based on the viscoelastic integral constitutive relation, the temperature response in truing process was calculated. The result showed that the maximum temperature in solid propellant truing process could attain up to 65 ℃ when the truing velocity was 10 mm/s and the truing thickness was 1 mm, and there was no remarkable temperature change under the truing thickness of 1.0 mm, 1.5 mm and 2.5 mm. The hazard in truing process of solid propellant was mainly close to the edge of cutting area.
基金financial support from the National Natural Science Foundation of China(Grant No.12102051)the State Key Laboratory of Explosion Science and Technology(Grant No.QNKT2022-04)。
文摘Due to its extremely low electrostatic sensitivity,copper azide primary explosive is greatly limited in practical applications.In this study,a composite film with Cu-MOF in-situ growth on carbon nanofilm was prepared by electrospinning and solvothermal methods,and CNF@Cu-N3film with electrostatic safety was obtained by carbonization and azide later.Its electrostatic sensitivity(E50)was greatly increased from 0.05 mJ of raw materials to 4.06 mJ,and still maintained a good detonation performance which could successfully detonate the CL-20 secondary explosive.This is mainly due to the synergistic effect of the carbon film and the MOF structure,which greatly improves the conductivity of the entire system and the uniform distribution of copper particles,providing a new preparation strategy for metal azide film that is suitable for the micro-initiator device.
基金the National Natural Science Foundation of China(Grant No.U2441263)for financial support of this work。
文摘In composite solid propellants with high aluminum(Al)content and low burning rate,incomplete combustion of the Al powder may occur.In this study,varying lithium(Li)content in Al-Li alloy powder was utilized instead of pure aluminum particles to mitigate agglomeration and enhance the combustion efficiency of solid propellants(Combustion efficiency herein refers to the completeness of metallic fuel oxidation,quantified as the ratio of actual-to-theoretical energy released during combustion)with high Al content and low burning rates.The impact of Al-Li alloy with different Li contents on combustion and agglomeration of solid propellant was investigated using explosion heat,combustion heat,differential thermal analysis(DTA),thermos-gravimetric analysis(TG),dynamic high-pressure combustion test,ignition experiment of small solid rocket motor(SRM)tests,condensation combustion product collection,and X-ray diffraction techniques(XRD).Compared with pure Al,Al-Li alloys exhibit higher combustion heat,which contributes to improved combustion efficiency in Al-Li alloy-containing propellants.DTA and TG analyses demonstrated higher reactivity and lower ignition temperatures for Al-Li alloys.High-pressure combustion experiments at 5 MPa showed that Al-Li alloy fuel significantly decreases combustion agglomeration.The results from theφ75 mm andφ165 mm SRM and XRD tests further support this finding.This study provides novel insights into the combustion and agglomeration behaviors of high-Al,low-burning-rate composite solid propellants and supports the potential application of Al-Li alloys in advanced propellant formulations.
基金funded by the National Natural Science Foundation of China(Grant No.22175059 and No.62264015)supported by the Scientific and Technological Innovation Team(2017CXTD-01)the 2021 Innovation and Entrepreneurship for Undergraduates(202110719019).
文摘Addressing the degradation of persistent organic pollutants like bisphenol A(BPA)and rhodamine B(RhB)with a photocatalyst that is both cost-effective and environmentally friendly is a notable challenge.This research presents the synthesis of an optimized g-C_(3)N_(4)/Bi_(4)O_(5)Br_(2)composite featuring a Z-scheme heterojunction structure.The precise band alignment of this composite significantly enhances the separation of photogenerated charges and the production of dominant reactive species.The composite demonstrated exceptional photocatalytic performance,with BPA degradation efficiency nearing 98%and RhB achieving complete degradation within 80 and 35 min under visible light,respectively.These results are approximately 1.3 times greater than the individual performance of CN and BOB,surpassing recent literature benchmarks.Through EPR and free radical capture experiments,the role of h^(+)and·O^(2−)as the primary active free radicals in the degradation process have been confirmed.First-principles calculations validated the experimental results,indicating that the Z-type heterojunction is instrumental in generating active species,thus improving degradation efficiency.This study offers a promising strategy for the design of photocatalysts targeting emerging organic pollutants.
基金supported by the Hubei Province Technology Innovation Program Project (2024BCB073)the National Natural Science Foundation of China (grant no. 32071318, T2350610283)+2 种基金the Shenzhen Science and Technology Innovation Committee (grant no. JCYJ20190807163007525)the Youth Innovation Promotion Association of the Chinese Academy of Sciences (grant no. 2022363)the support from the King Mongkut’s University of Technology Thonburi, Bangkok, Thailand
文摘Biosensors are crucial for detecting various analytes relevant to bioanalytical applications.To enhance the specificity and sensitivity of biosensors,bimetallic nanoparticles(BNPs)have been utilized,which demonstrate significant potential for sensing applications owing to their constituent materials’inherent properties,small size,unique architectural features,and biomimetic behavior.Among BNPs,Au-Ag BNPs are promising for sensing applications owing to their small size,high sensitivity,and distinctive characteristics.Herein,we first briefly present the development of Au-Ag BNPs and discuss the fundamentals.Subsequently,we present the relationship between the synthesis method and structure of Au-Ag BNPs.Furthermore,recent advancements in Au-Ag BNPs are highlighted for their role in enhancing biosensors,particularly for electrode modifiers,signal amplifiers,and recognition materials.Finally,we propose several existing challenges and summarize insights pertaining to the potential development of Au-Ag BNPs for biosensing applications.
基金Joint Funds of National Natural Science Foundation of China,Grant/Award Number:U2141202National Natural Science Foundation of China,Grant/Award Numbers:12102194,21905084,22105103Natural Science Foundation of Jiangsu Province,Grant/Award Number:BK20200471。
文摘It is still a huge challenge to introduce effective crack-healing ability into energetic composites with a high oxidizer content.In this article,a poly(urea-urethane)energetic elastomer was prepared by the polycondensation reaction of glycidyl azido polymer(GAP),isophorone diisocyanate(IPDI),and 2-aminophenyl disulfide(2-APD).In the poly(urea-urethane)elastomer structure,the hybrid dynamic lock,including multilevel H-bonds and disulfide bonds,not only provides abundant dynamic interactions and promotes chain diffusion,but also enhances physical crosslinking density.Such a unique design fabricated the energetic elastomer with robust tensile strength(0.72MPa),high stretchability(1631%),and outstanding toughness(8.95MJ/m 3)in the field of energetic polymers.Meanwhile,this energetic elastomer exhibited high self-healing efficiency(98.4%at 60°C)and heat release(Q=1750.46J/g).Experimental and theoretical results adequately explain the self-healing mechanism,particularly the role of azido units.The high-solid content(80wt%)energetic composites based on the energetic elastomer presented outstanding micro-defect self-healing(97.8%)and recycling without loss of mechanical performance.The development of smart energetic composites with excellent self-healing and recyclable ability provides a meaningful way for a wide range of applications in the field of energetic materials.
基金supported by the National Science Foundation of China(No.22175059 and 62264015).
文摘Environmental contamination by hexavalent chromium(Cr(VI))and antibiotic drug residues pose significant chal-lenges to public health and ecosystems.This study investigates the application ofCoTiO_(3)/BiVO_(4)@MIL-Fe(53)(CT/BV@Fe-MOF)for the reduction of Cr(VI)and degradation of tetracycline(TCL)under visible light.After grafting an iron-based metal–organic framework MIL-Fe(53)on a modified CoTiO_(3)/BiVO_(4)composite,the photogenerated electrons could easily be transferred from CoTiO_(3)to BiVO_(4)/Fe-MOF species via interfacial charge transfer.UV–vis diffuse reflec-tance spectroscopy showed that charge carriers were formed in response to visible light absorption.The effect of different operating parameters,including catalyst load,pH,initial Cr(VI),and TCL concentration,was systematically evaluated during the photocatalytic process.The CT/BV@Fe-MOF composite exhibited 98.7%reduction efficiency in Cr(VI)(50 ppm)and 97.5%degradation efficiency towards TCL(30 ppm)within 90 min,resulting in a greater efficiency than the pristine CoTiO_(3),BiVO_(4),and Fe-MOF materials.The CT/BV@Fe-MOF composite displayed excellent stability over six cycles,highlighting its potential for practical applications.In addition,the plausible degradation pathway of TCL was evaluated using LC-ESI/MS analysis,while the TEST program was utilized to investigate the toxicity of the products generated during the degradation process.
基金supported by the National Natural Science Foundation of China(21875026,21878031)the Program for Liaoning Excellent Talents in University(LR2014013)+2 种基金the Science and Technology Foundation of Liaoning Province(No.201602052)the Natural Science Foundation of Liaoning Province(No.20170520427)by the Liaoning Revitalization Talents Program(XLYC1802124).
文摘Devising a desirable nano-heterostructured photoelectrode based on the charge transfer kinetics mechanism is a pivotal strategy for implementing efficient photoelectrocatalytic(PEC)technology,since the charge separation and utilization efficiency of a photoelectrode is critical to its PEC performance.Herein,we fabricate a F–Co_(3)O_(4)@Bi_(2)WO_(6) core–shell hetero-array photoanode by coupling Bi_(2)WO_(6) nanosheets with F–Co_(3)O_(4) nanowires using a simple solvothermal solution method.The three-dimensional hierarchical heterostructure has a homogeneous chemical interface,helping it to promote an S-scheme-based carrier transport kinetics and maintain excellent cycling stability.Charge density difference calculations verify the electron migration trend from F–Co_(3)O_(4) to Bi_(2)WO_(6) upon hybridization and the formation of an internal electric field in the heterojunction,consistent with the S-scheme mechanism,which is identified by in situ irradiation X-ray photoelectron spectroscopy and by ultraviolet photoelectron spectroscopy.The optimized F–Co_(3)O_(4)@Bi_(2)WO_(6)-2 photoelectrode achieves high carrier utilization efficiency and exhibits superior PEC degradation performance for various organic pollutants,including reactive brilliant blue KN-R,rhodamine B,sulfamethoxazole,and bisphenol A.This work not only reveals that F–Co_(3)O_(4)@Bi_(2)WO_(6)-2 is effective for PEC water remediation but also provides a strategy to enhance carrier transport kinetics by designing binary oxides.
基金supported by the Science and Technology on Aerospace Chemical Power Laboratory,Hubei Institute of Aerospace Chemical Technology(U20B2018)the Open Research Fund Program of Science and Technology on Aerospace Chemical Power Laboratory(STACPL320201B02 and STACPL320181B03-1)the National Natural Science Foundation of China(Nos.61971204 and 51902114).
文摘Efficient chemicalwarfare agents(CWAs)detection is required to protect people from the cWAs in war and terrorism.In this work,a Pd-doped SnO_(2)nanoparticles-based gas sensor was developed to detect a nerve agent simulant named methyl salicylate.The sensing measurements of methyl salicylate under different Pd doping amounts found that the 0.5 at.%Pd-doped SnO_(2)exhibited a significant improvement in the detection of methyl salicylate at the ppb(1ppb=10-9)level,and the response value to 160 ppb methyl salicylate is 0.72 at 250℃.Compared with the pure SnO_(2),the response value is increased by 4.5 times,which could be attributed to the influence of the noble metal Pd on the oxygen state and its catalytic effect.In addition,the 0.5at.%Pd-doped SnO_(2)sensor still has an obvious response to 16ppb methyl salicylate with a response value of 0.13,indicating the lower detection limit of the sensor.
