Copper-based azide(Cu(N_(3))2 or CuN_(3),CA)chips synthesized by in-situ azide reaction and utilized in miniaturized explosive systems has become a hot research topic in recent years.However,the advantages of in-situ ...Copper-based azide(Cu(N_(3))2 or CuN_(3),CA)chips synthesized by in-situ azide reaction and utilized in miniaturized explosive systems has become a hot research topic in recent years.However,the advantages of in-situ synthesis method,including small size and low dosage,bring about difficulties in quantitative analysis and differences in ignition capabilities of CA chips.The aim of present work is to develop a simplified quantitative analysis method for accurate and safe analysis of components in CA chips to evaluate and investigate the corresponding ignition ability.In this work,Cu(N_(3))2 and CuN_(3)components in CA chips were separated through dissolution and distillation by utilizing the difference in solubility and corresponding content was obtained by measuring N_(3)-concentration through spectrophotometry.The spectrophotometry method was optimized by studying influencing factors and the recovery rate of different separation methods was studied,ensuring the accuracy and reproducibility of test results.The optimized method is linear in range from 1.0-25.0 mg/L,with a correlation coefficient R^(2)=0.9998,which meets the requirements of CA chips with a milligram-level content test.Compared with the existing ICP method,component analysis results of CA chips obtained by spectrophotometry are closer to real component content in samples and have satisfactory accuracy.Moreover,as its application in miniaturized explosive systems,the ignition ability of CA chips with different component contents for direct ink writing CL-20 and the corresponding mechanism was studied.This study provided a basis and idea for the design and performance evaluation of CA chips in miniaturized explosive systems.展开更多
Copper-based metal-organic frameworks(Cu-MOFs)are a promising multiphase catalyst for catalyzing C-S coupling reactions by virtue of their diverse structures and functions.However,the unpleasant odor and instability o...Copper-based metal-organic frameworks(Cu-MOFs)are a promising multiphase catalyst for catalyzing C-S coupling reactions by virtue of their diverse structures and functions.However,the unpleasant odor and instability of the organosulfur,as well as the mass-transfer resistance that exists in multiphase catalysis,have often limited the catalytic application of Cu-MOFs in C-S coupling reactions.In this paper,a Cu-MOFs catalyst modified by cetyltrimethylammonium bromide(CTAB)was designed to enhance mass transfer by increasing the adsorption of organic substrates using the long alkanes of CTAB.Concurrently,elemental sulfur was used to replace organosulfur to achieve a highly efficient and atom-economical multicomponent C-S coupling reaction.展开更多
Carbon-doped copper ferrite(C–CuFe_(2)O_(4))was synthesized by a simple two-step hydrothermal method,which showed enhanced tetracycline hydrochloride(TCH)removal efficiency as compared to the pure CuFe_(2)O_(4) in Fe...Carbon-doped copper ferrite(C–CuFe_(2)O_(4))was synthesized by a simple two-step hydrothermal method,which showed enhanced tetracycline hydrochloride(TCH)removal efficiency as compared to the pure CuFe_(2)O_(4) in Fenton-like reaction.A removal efficiency of 94%was achieved with 0.2 g L^(-1) catalyst and 20 mmol L^(-1) H_(2)O_(2) within 90 min.We demonstrated that 5%C–CuFe_(2)O_(4) catalyst in the presence of H_(2)O_(2) was significantly efficient for TCH degradation under the near-neutral pH(5–9)without buffer.Multiple techniques,including SEM,TEM,XRD,FTIR,Raman,XPS M€ossbauer and so on,were conducted to investigate the structures,morphologies and electronic properties of as-prepared samples.The introduction of carbon can effectively accelerate electron transfer by cooperating with Cu and Fe to activate H_(2)O_(2) to generate·OH and·O_(2)^(-).Particularly,theoretical calculations display that the p,p,d orbital hybridization of C,O,Cu and Fe can form C–O–Cu and C–O–Fe bonds,and the electrons on carbon can transfer to metal Cu and Fe along the C–O–Fe and C–O–Cu channels,thus forming electron-rich reactive centers around Fe and Cu.This work provides lightful reference for the modification of spinel ferrites in Fenton-like application.展开更多
Catalytic wet air oxidation(CWAO) can degrade some refractory pollutants at a low cost to improve the biodegradability of wastewater. However, in the presence of high temperature and high pressure and strong oxidizing...Catalytic wet air oxidation(CWAO) can degrade some refractory pollutants at a low cost to improve the biodegradability of wastewater. However, in the presence of high temperature and high pressure and strong oxidizing free radicals, the stability of catalysts is often insufficient, which has become a bottleneck in the application of CWAO. In this paper, a copper-based catalyst with excellent hydrothermal stability was designed and prepared. TiO_(2) with excellent stability was used as the carrier to ensure the longterm anchoring of copper and reduce the leaching of the catalyst. The one pot sol–gel method was used to ensure the super dispersion and uniform distribution of copper nanoparticles on the carrier, so as to ensure that more active centers could be retained in a longer period. Experiments show that the catalyst prepared by this method has good stability and catalytic activity, and the catalytic effect is not significantly reduced after 10 cycles of use. The oxidation degradation experiment of m-cresol with the strongest biological toxicity and the most difficult to degrade in coal chemical wastewater was carried out with this catalyst. The results showed that under the conditions of 140℃, 2 MPa and 2 h, m-cresol with a concentration of up to 1000 mg·L^(-1) could be completely degraded, and the COD removal rate could reach 79.15%. The biological toxicity of wastewater was significantly reduced. The development of the catalyst system has greatly improved the feasibility of CWAO in the treatment of refractory wastewater such as coal chemical wastewater.展开更多
The use of Fenton's reagent (Fe^2+/H2O2) and Fenton-like reagents containing transition metals of Cu(Ⅱ), Zn(Ⅱ), Co(Ⅱ), and Mn(Ⅱ) for an alum sludge conditioning to improve its dewaterability was invest...The use of Fenton's reagent (Fe^2+/H2O2) and Fenton-like reagents containing transition metals of Cu(Ⅱ), Zn(Ⅱ), Co(Ⅱ), and Mn(Ⅱ) for an alum sludge conditioning to improve its dewaterability was investigated. The results obtained were compared with those obtained from conditioning the same alum sludge using cationic and anionic polymers. Experimental results show that Fenton's reagent was the best among the Fenton and Fenton-like reagents for the alum sludge conditioning. A considerable effectiveness of capillary suction time (CST) reduction efficiency of 47% can be achieved under test conditions of Fe^2+/H2O2 = 20/125 mg/g DS (dry solid) and pH 6.0. The observation of floc-like particles after Fenton's reagent conditioning of alum sludge suggested that the mechanism of Fenton's reagent conditioning was different from that of polymer conditioning. In spite of the lower efficiency in the CST reduction of Fenton's reagent in alum sludge conditioning compared to that of polymer conditioning, Fenton's reagent offers a more environmentally safe option. Tiffs study provided an example of proactive treatment engineering, which is aimed at seeking a safe alternative to the use of polymers in sludge conditioning towards achieving a more sustainable sludge management strategy.展开更多
The nano ZrO2-supported copper-based catalysts for methane combustion were investigated by means of N2 adsorption, TEM, XRD, H2-TPR techniques and the test of methane oxidation. Two kinds of ZrO2 were used as support,...The nano ZrO2-supported copper-based catalysts for methane combustion were investigated by means of N2 adsorption, TEM, XRD, H2-TPR techniques and the test of methane oxidation. Two kinds of ZrO2 were used as support, one (ZrO2-1) was obtained from the commercial ZrO2 and the other (ZrO2-2) was issued from the thermal decomposition of zirconium nitrate. It was found that the CuO/ZrO2-2 catalyst was more active than CuO/ZrO2-1. N2 adsorption, H2-TPR and XRD measurements showed that larger surface area, better reduction property, presence of tetragonal ZrO2 and higher dispersion of active component for CuO/ZrO2-2 than that of CuO/ZrO2-1. These factors could be the dominating reasons for its higher activity for methane combustion.展开更多
To overcome the ever-growing organic pollutions in the water system,abundant efforts have been dedicated to fabricating efficient Fenton-like carbon catalysts.However,the rational design of carbon catalysts with high ...To overcome the ever-growing organic pollutions in the water system,abundant efforts have been dedicated to fabricating efficient Fenton-like carbon catalysts.However,the rational design of carbon catalysts with high intrinsic activity remains a long-term goal.Herein,we report a new N-molecule-assisted self-catalytic carbonization process in augmenting the intrinsic Fenton-like activity of metal-organic-framework-derived carbon hybrids.During carbonization,the N-molecules provide alkane/ammonia gases and the formed iron nanocrystals act as the in situ catalysts,which result in the elaborated formation of carbon nanotubes(in situ chemical vapor deposition from alkane/iron catalysts)and micro-/meso-porous structures(ammonia gas etching).The obtained catalysts exhibited with abundant Fe/Fe-Nx/pyridinic-N active species,micro-/meso-porous structures,and conductive carbon nanotubes.Consequently,the catalysts exhibit high efficiency toward the degradation of different organic pollutions,such as bisphenol A,methylene blue,and tetracycline.This study not only creates a new pathway for achieving highly active Fenton-like carbon catalysts but also takes a step toward the customized production of advanced carbon hybrids for diverse energy and environmental applications.展开更多
The sluggish kinetics of Fe(Ⅱ)recovery in Fenton/Fenton-like reactions significantly limits the oxidation efficiency.In this study,we for the first time use boron carbide(BC)as a green and stable promotor to enhance ...The sluggish kinetics of Fe(Ⅱ)recovery in Fenton/Fenton-like reactions significantly limits the oxidation efficiency.In this study,we for the first time use boron carbide(BC)as a green and stable promotor to enhance the reaction of Fe(Ⅲ)/H_(2)O_(2) for degradation of diverse organic pollutants.Electron paramagnetic resonance analysis and chemical quenching/capturing experiments demonstrate that hydroxyl radicals(·OH)are the primary reactive species in the BC/Fe(Ⅲ)/H_(2)O_(2) system.In situ electrochemical analysis indicates that BC remarkably boosts the Fe(Ⅲ)/Fe(Ⅱ)redox cycles,where the adsorbed Fe(Ⅲ)cations were transformed to more active Fe(Ⅲ)species with a higher oxidative potential to react with H_(2)O_(2) to produce Fe(Ⅱ).Thus,the recovery of Fe(Ⅱ)from Fe(Ⅲ)is facilitated over BC surface,which enhancesOH generation via Fenton reactions.Moreover,BC exhibits outstanding reusability and stability in successive cycles and avoids the secondary pollution caused by conventional organic and metalliferous promotors.Therefore,metal-free BC boosting Fe(Ⅲ)/H_(2)O_(2) oxidation of organics provides a green and advanced strategy for water decontamination.展开更多
Heterogeneous Fenton-like process using fly ash as a catalyst was studied to degrade n-butyl xanthate form aqueous solution. The different reaction parameters on the degradation efficiency of the process were investig...Heterogeneous Fenton-like process using fly ash as a catalyst was studied to degrade n-butyl xanthate form aqueous solution. The different reaction parameters on the degradation efficiency of the process were investigated. The fly ash/H2O2 catalyst possesses a high oxidation activity for n-butyl xanthate degradation in aqueous solution. It is found that both the dosage of catalyst and initial solution pH significantly affect the n-butyl xanthate conversion efficient. The results indicate that by using 1.176 mmol/L H2O2 and 1.0 g/L fly ash catalyst with mass fraction of 4.14% Fe(III) oxide at pH 3.0, almost 96.90% n-butyl xanthate conversion and over 96.66% COD removal can be achieved within 120 min with heterogeneous catalysis by fly ash. CS2 as an intermediate of n-butyl xanthate oxidation. Finally, it is demonstrated that the fly ash/H2O2 catalytic oxidation process can be an efficient method for the treatment of n-butyl xanthate containing wastewater.展开更多
Various Cu/ZnO/Al2O3 catalysts have been synthesized by different aluminum emulsions as aluminum sources and their pertormances tor methanol synthesis from syngas have been investigated. The influences of preparation ...Various Cu/ZnO/Al2O3 catalysts have been synthesized by different aluminum emulsions as aluminum sources and their pertormances tor methanol synthesis from syngas have been investigated. The influences of preparation methods of aluminum emulsions on physicochemical and catalytic properties of catalysts were studied by XRD, SEM, XPS,N2 adsorption-desorption techniques and methanol synthesis from syngas. The preparation methods of aluminum emulsions were found to influence the catalytic activity, CuO crystallite size, surface area and Cu0 surface area and reduction process. The results show that the catalyst CN using the aluminum source prepared by addition the ammonia into the aluminum nitrate (NP) exhibited the best catalytic performance for methanol synthesis from syngas.展开更多
Pure metal-doped(Cu,Zn)Fe2O4 was synthesized from Zn-containing electric arc furnace dust(EAFD)by solid-state reaction using copper salt as additive.The effects of pretreated EAFD-to-Cu2(OH)2CO3·6H2O mass ratio,c...Pure metal-doped(Cu,Zn)Fe2O4 was synthesized from Zn-containing electric arc furnace dust(EAFD)by solid-state reaction using copper salt as additive.The effects of pretreated EAFD-to-Cu2(OH)2CO3·6H2O mass ratio,calcination time,and calcination temperature on the structure and catalytic ability were systematically studied.Under the optimum conditions,the decolorization efficiency and total organic carbon(TOC)removal efficiency of the as-prepared ferrite for treating a Rhodamine B solution were approximately 90.0%and 45.0%,respectively,and the decolorization efficiency remained 83.0%after five recycles,suggesting that the as-prepared(Cu,Zn)Fe2O4 was an efficient heterogeneous Fenton-like catalyst with high stability.The high catalytic activity mainly depended on the synergistic effect of iron and copper ions occupying octahedral positions.More importantly,the toxicity characteristic leaching procedure(TCLP)analysis illustrated that the toxic Zncontaining EAFD was transformed into harmless(Cu,Zn)Fe2O4 and that the concentrations of toxic ions in the degraded solution were all lower than the national emission standard(GB/31574-2015),further confirming that the as obtained sample is an environment-friendly heterogeneous Fenton-like catalyst.展开更多
Recently,inorganic copper-based halide perovskites and their derivatives(CHPs)with chemical formulas AlCumXn(A=Rb and Cs;X=Cl,Br and I;l,m,and n are integers.),have received increasing attention in the photoluminescen...Recently,inorganic copper-based halide perovskites and their derivatives(CHPs)with chemical formulas AlCumXn(A=Rb and Cs;X=Cl,Br and I;l,m,and n are integers.),have received increasing attention in the photoluminescence field,due to their lead-free,cost-effective,earth-abundant and low electronic dimensionality.Ascribed to flexible valence charge of Cu(Cu1+and Cu2+)and complex competing phases,the crystal structures and phase stabilities of CHPs are complicated and ambiguous,which limits their experimental applications.Via comprehensive first-principles calculations,we have investigated thermodynamic stabilities of possible crystal phases for AlCumXn by considering all the possible secondary phases existing in inorganic crystal structure database(ICSD).Our results are in agreement with existing experiments and further predicted the existence of 10 stable CHPs,i.e.Rb3 Cu2 Br5,Rb3 Cu2 I5,Rb Cu2 Cl3,Rb2 Cu I3,Rb2 Cu Br4,Rb Cu Br3,Rb3 Cu2 Br7,Cs3 Cu2 Br7,Cs3 Cu2 Cl7 and Cs4 Cu5 Cl9,which have not yet been reported in experiments.This work provides a phase and compositional map that may guide experiments to synthesize more novel inorganic CHPs with diverse properties for potential functional applications.展开更多
Chemical looping combustion(CLC)is an energy conversion technology with high efficiency and inherent separation of CO_(2).The existence of sulfur in coal may affect the CO_(2) purity and the performance of oxygen carr...Chemical looping combustion(CLC)is an energy conversion technology with high efficiency and inherent separation of CO_(2).The existence of sulfur in coal may affect the CO_(2) purity and the performance of oxygen carrier due to the interactions between sulfur contaminants and oxygen carrier.The migration of sulfur in Beisu coal during the in-situ gasification chemical looping combustion(i G-CLC)process using two oxygen carriers(iron ore and Cu O/Si O_(2))was investigated respectively.The thermodynamic analysis results showed the formation of metal sulfides was thermodynamically favored at low temperatures and low oxygen excess coefficients,while they were obviously inhibited and the production of SO_(2) was significantly promoted with an increase in temperature and oxygen excess coefficient.Moreover,part of sulfur was captured and fixed in the forms of alkali/alkaline earth metal sulfate due to the high amount of alkali/alkaline earth metal oxides in the coal ash or/and oxygen carrier.The experimental results showed that the sulfur in coal mainly released in the form of SO_(2),and the sulfur conversion efficiency(XS)in the reduction stage were 51.04%and 48.24%when using iron ore and Cu O/Si O_(2) respectively.The existence of metal sulfides was observed in the reduced oxygen carriers.The values of XSin the reoxidation process reached 3.80%and 7.64%when using iron ore and Cu O/Si O_(2) respectively.The residue and accumulation of sulfur were also found on the surfaces of two oxygen carriers.展开更多
During the oxidative degradation of nonbiodegradable Malachite green (MG) by means of H2O2 /FeIIIR (iron supported on ion-exchage resin) in a dynamic column,the binding energy of the Fe(2p3/2) region for XPS spectra w...During the oxidative degradation of nonbiodegradable Malachite green (MG) by means of H2O2 /FeIIIR (iron supported on ion-exchage resin) in a dynamic column,the binding energy of the Fe(2p3/2) region for XPS spectra was found to be different between the top layer and the bottom layer in this column. Based on the data from XPS spectra and DMPO-OH·signal by EPR spectra,it is shown that the formation of ferryl (IV) is the key step for the oxidation of MG. The ferryl (IV) species can oxidize MG,and its redox potential is about 0. 739 - 0. 803 V measured by cyclic voltammograms (CV) . The catalytic capability of ferryl (IV) species was also evaluated,and it is found that it can promote the decomposition of H2O2 more efficiently than ferric iron. The removal rate of MG mainly depends on the adsorption of catalyst. Both ferryl (IV) and HO·radicals are the reactive species in the system. The oxidation of HO·is only a small part of the overall removal rate. Based on the obtained results,a possible mechanism for a resin-supported Fenton-like oxidation reaction is proposed.展开更多
In this study,a novel magnetically separable adsorbent,molecular imprinting magnetic γ-Fe_2O_3/crosslinked chitosan composites(MIPs),were prepared by a microemulsion process.Adsorption and Fenton-like oxidative degra...In this study,a novel magnetically separable adsorbent,molecular imprinting magnetic γ-Fe_2O_3/crosslinked chitosan composites(MIPs),were prepared by a microemulsion process.Adsorption and Fenton-like oxidative degradation of a model pharmaceutical pollutant norfloxacin(NOR) by using MIPs were investigated.Various characterization methods were used to study the properties of MIPs,and it is suggested that the hydroxyl groups are the main adsorption sites for NOR.MIPs present better selective adsorption for NOR than its reference antibiotic sulfadiazine.The NOR adsorption data can be well fitted by Langmuir isotherm model and pseudosecond-order kinetic model.The optimum pH range for NOR adsorption is 7-10.In addition,the MIP-catalyzed Fenton-like system(MIPs/H_2O_2) exhibits remarkably faster removal rate for NOR than the case of γ-Fe_2O_3/H_2O_2.The result indicates that MIPs will be a good functional material in decontamination of pharmaceutical wastewaters since MIPs can be magnetically recycled after the treatment.展开更多
Between the two major arsenic-containing salts in natural water, arsenite(As(Ⅲ)) is far more harmful to human and the environment than arsenate(As(V)) due to its high toxicity and transportability. Therefore, preoxid...Between the two major arsenic-containing salts in natural water, arsenite(As(Ⅲ)) is far more harmful to human and the environment than arsenate(As(V)) due to its high toxicity and transportability. Therefore, preoxidation of As(Ⅲ) to As(V) is considered to be an effective means to reduce the toxicity of arsenic and to promote the removal efficiency of arsenic. Due to their high catalytic activity and arsenic affinity, iron-based functional materials can quickly oxidize As(Ⅲ) to As(V) in heterogeneous Fenton-like systems, and then remove As(V) from water through adsorption and surface coprecipitation. In this review, the effects of different iron-based functional materials such as zero-valent iron and iron(hydroxy) oxides on arsenic removal are compared, and the catalytic oxidation mechanism of As(Ⅲ) in heterogeneous Fenton process is further clarified. Finally, the main challenges and opportunities faced by iron-based As(Ⅲ) oxidation functional materials are prospected.展开更多
[Objectives] The effects of copper-based nutrient foliar fertilizer on photosynthetic characteristics,yield,accumulation and distribution of trace elements in various organs,disease prevention effect and soil enzyme a...[Objectives] The effects of copper-based nutrient foliar fertilizer on photosynthetic characteristics,yield,accumulation and distribution of trace elements in various organs,disease prevention effect and soil enzyme activity were studied,so as to provide a theoretical basis for the application of foliar fertilizers in cotton production. [Methods]Through two years of field experiments,six treatments were set in total,namely spraying water( CK),traditional Bordeaux mixture( BDM),Kocide 2000( KCD),copper-based nutrient foliar fertilizer( CF),iron-copper-based nutrient foliar fertilizer( CFFe),and zinc-boron-copper-based nutrient foliar fertilizer( CFZnB). Randomized block arrangement was adopted. Chlorophyll content in leaves was measured at each growth stage of the cotton. Photosynthetic characteristics of leaves were measured at the peak bolling stage. Plants were sampled at initial boll opening stage. The whole plant was divided into root,stem,leaf and cotton boll parts,in which the total copper,total zinc,total iron contents and accumulations were determined. Soil samples were collected from each plot,followed by the determination of soil enzyme activity. Disease index was investigated at bud,flowering and boll-forming and boll opening stage. [Results]( 1) Spraying CFFe,CFZnB,CF and KCD could significantly improve chlorophyll content of cotton leaves,and the CFFe treatment had the highest increase up to13. 30%,followed by the CFZnB treatment,which was 11. 40% higher than the CK; and photosynthetic rate,stomata conductance and transpiration rate could be improved significantly,and the CFFe treatment showed the highest photosynthetic rate,which increased by 26. 35% compared with the CK,followed by the CFZnB treatment,which increased by 17. 96% compared with CK; and intercellular CO2 concentration was significantly reduced.( 2) Spraying BDM,KCD,CF,CFFe and CFZnB can significantly increase total copper content and accumulation in various cotton organs( except the total copper content in the stem part of the CFZnB treatment; the CFZnB and CFFe treatments can significantly increase total zinc content and accumulation in various cotton organs; and spraying CFFe,CFZnB and CF can significantly increase total iron content and accumulation in various cotton organs( except the total iron content in the stem part of the CF treatment).( 3)Spraying CFFe,CFZnB,CF,KCD and BDM greatly reduced the disease index at flowering and boll-forming and boll opening stages.( 4) The CFZnB and CFFe treatments had the highest soil urease activity,which was 7. 14% higher than that of the CK,but the difference from the CK was not significant; the catalase activity of each treatment was significantly higher than that of the BDM treatment; and the sucrase activity of each treatment was significantly higher than that of the CK.( 5) Spraying CFFe,CFZnB,CF and KCD significantly improved lint yield of cotton,and the CFZnB treatment showed the highest yield increase up to 12. 34%,followed by the CFFe treatment,with an increase in the range of 8. 77%-10. 20%. [Conclusions]Copper-based nutrient foliar fertilizers have dual functions of disease control and prevention and plant nutrition and health care,and not only can significantly increase cotton yield,but also has certain disease prevention effect.It is recommended to use copper-based nutrient foliar fertilizers.展开更多
基金the financial support provided by the National Natural Science Foundation of China(Grant No.11872013).
文摘Copper-based azide(Cu(N_(3))2 or CuN_(3),CA)chips synthesized by in-situ azide reaction and utilized in miniaturized explosive systems has become a hot research topic in recent years.However,the advantages of in-situ synthesis method,including small size and low dosage,bring about difficulties in quantitative analysis and differences in ignition capabilities of CA chips.The aim of present work is to develop a simplified quantitative analysis method for accurate and safe analysis of components in CA chips to evaluate and investigate the corresponding ignition ability.In this work,Cu(N_(3))2 and CuN_(3)components in CA chips were separated through dissolution and distillation by utilizing the difference in solubility and corresponding content was obtained by measuring N_(3)-concentration through spectrophotometry.The spectrophotometry method was optimized by studying influencing factors and the recovery rate of different separation methods was studied,ensuring the accuracy and reproducibility of test results.The optimized method is linear in range from 1.0-25.0 mg/L,with a correlation coefficient R^(2)=0.9998,which meets the requirements of CA chips with a milligram-level content test.Compared with the existing ICP method,component analysis results of CA chips obtained by spectrophotometry are closer to real component content in samples and have satisfactory accuracy.Moreover,as its application in miniaturized explosive systems,the ignition ability of CA chips with different component contents for direct ink writing CL-20 and the corresponding mechanism was studied.This study provided a basis and idea for the design and performance evaluation of CA chips in miniaturized explosive systems.
基金support from the National Natural Science Foundation of China(22078130)the Fundamental Research Funds for the Central Universities(1042050205225990/010)Starting Research Fund of Qingyuan Innovation Laboratory(00523001).
文摘Copper-based metal-organic frameworks(Cu-MOFs)are a promising multiphase catalyst for catalyzing C-S coupling reactions by virtue of their diverse structures and functions.However,the unpleasant odor and instability of the organosulfur,as well as the mass-transfer resistance that exists in multiphase catalysis,have often limited the catalytic application of Cu-MOFs in C-S coupling reactions.In this paper,a Cu-MOFs catalyst modified by cetyltrimethylammonium bromide(CTAB)was designed to enhance mass transfer by increasing the adsorption of organic substrates using the long alkanes of CTAB.Concurrently,elemental sulfur was used to replace organosulfur to achieve a highly efficient and atom-economical multicomponent C-S coupling reaction.
基金supported by the Program for the National Natural Science Foundation of China(52070077,51879101,51779090)the National Program for Support of Top-Notch Young Professionals of China(2014)+1 种基金the Program for Changjiang Scholars and Innovative Research Team in University(IRT-13R17)Natural Science Foundation of Hunan Province(2022JJ20013,2021JJ40098).
文摘Carbon-doped copper ferrite(C–CuFe_(2)O_(4))was synthesized by a simple two-step hydrothermal method,which showed enhanced tetracycline hydrochloride(TCH)removal efficiency as compared to the pure CuFe_(2)O_(4) in Fenton-like reaction.A removal efficiency of 94%was achieved with 0.2 g L^(-1) catalyst and 20 mmol L^(-1) H_(2)O_(2) within 90 min.We demonstrated that 5%C–CuFe_(2)O_(4) catalyst in the presence of H_(2)O_(2) was significantly efficient for TCH degradation under the near-neutral pH(5–9)without buffer.Multiple techniques,including SEM,TEM,XRD,FTIR,Raman,XPS M€ossbauer and so on,were conducted to investigate the structures,morphologies and electronic properties of as-prepared samples.The introduction of carbon can effectively accelerate electron transfer by cooperating with Cu and Fe to activate H_(2)O_(2) to generate·OH and·O_(2)^(-).Particularly,theoretical calculations display that the p,p,d orbital hybridization of C,O,Cu and Fe can form C–O–Cu and C–O–Fe bonds,and the electrons on carbon can transfer to metal Cu and Fe along the C–O–Fe and C–O–Cu channels,thus forming electron-rich reactive centers around Fe and Cu.This work provides lightful reference for the modification of spinel ferrites in Fenton-like application.
基金support provided by the National Natural Science Foundation of China (21978143 and 21878164)。
文摘Catalytic wet air oxidation(CWAO) can degrade some refractory pollutants at a low cost to improve the biodegradability of wastewater. However, in the presence of high temperature and high pressure and strong oxidizing free radicals, the stability of catalysts is often insufficient, which has become a bottleneck in the application of CWAO. In this paper, a copper-based catalyst with excellent hydrothermal stability was designed and prepared. TiO_(2) with excellent stability was used as the carrier to ensure the longterm anchoring of copper and reduce the leaching of the catalyst. The one pot sol–gel method was used to ensure the super dispersion and uniform distribution of copper nanoparticles on the carrier, so as to ensure that more active centers could be retained in a longer period. Experiments show that the catalyst prepared by this method has good stability and catalytic activity, and the catalytic effect is not significantly reduced after 10 cycles of use. The oxidation degradation experiment of m-cresol with the strongest biological toxicity and the most difficult to degrade in coal chemical wastewater was carried out with this catalyst. The results showed that under the conditions of 140℃, 2 MPa and 2 h, m-cresol with a concentration of up to 1000 mg·L^(-1) could be completely degraded, and the COD removal rate could reach 79.15%. The biological toxicity of wastewater was significantly reduced. The development of the catalyst system has greatly improved the feasibility of CWAO in the treatment of refractory wastewater such as coal chemical wastewater.
基金The first author would like to appreciate Ministry of Higher Education, Missions Department, Egypt for the fi- nancial support granted through Channel Scheme Mission.
文摘The use of Fenton's reagent (Fe^2+/H2O2) and Fenton-like reagents containing transition metals of Cu(Ⅱ), Zn(Ⅱ), Co(Ⅱ), and Mn(Ⅱ) for an alum sludge conditioning to improve its dewaterability was investigated. The results obtained were compared with those obtained from conditioning the same alum sludge using cationic and anionic polymers. Experimental results show that Fenton's reagent was the best among the Fenton and Fenton-like reagents for the alum sludge conditioning. A considerable effectiveness of capillary suction time (CST) reduction efficiency of 47% can be achieved under test conditions of Fe^2+/H2O2 = 20/125 mg/g DS (dry solid) and pH 6.0. The observation of floc-like particles after Fenton's reagent conditioning of alum sludge suggested that the mechanism of Fenton's reagent conditioning was different from that of polymer conditioning. In spite of the lower efficiency in the CST reduction of Fenton's reagent in alum sludge conditioning compared to that of polymer conditioning, Fenton's reagent offers a more environmentally safe option. Tiffs study provided an example of proactive treatment engineering, which is aimed at seeking a safe alternative to the use of polymers in sludge conditioning towards achieving a more sustainable sludge management strategy.
文摘The nano ZrO2-supported copper-based catalysts for methane combustion were investigated by means of N2 adsorption, TEM, XRD, H2-TPR techniques and the test of methane oxidation. Two kinds of ZrO2 were used as support, one (ZrO2-1) was obtained from the commercial ZrO2 and the other (ZrO2-2) was issued from the thermal decomposition of zirconium nitrate. It was found that the CuO/ZrO2-2 catalyst was more active than CuO/ZrO2-1. N2 adsorption, H2-TPR and XRD measurements showed that larger surface area, better reduction property, presence of tetragonal ZrO2 and higher dispersion of active component for CuO/ZrO2-2 than that of CuO/ZrO2-1. These factors could be the dominating reasons for its higher activity for methane combustion.
基金supported by the National Key R&D Program of China(2019YFA0110600 and 2019YFA0110601)National Natural Science Foundation of China(Nos.51603134,51903178,51803134,and 51703141)+1 种基金Sichuan Province’s Science and Technology Planning Project(No.2016GZ0350)the Postgraduate Course Construction Project of Sichuan University(No.2017KCSJ036)and for their financial support.
文摘To overcome the ever-growing organic pollutions in the water system,abundant efforts have been dedicated to fabricating efficient Fenton-like carbon catalysts.However,the rational design of carbon catalysts with high intrinsic activity remains a long-term goal.Herein,we report a new N-molecule-assisted self-catalytic carbonization process in augmenting the intrinsic Fenton-like activity of metal-organic-framework-derived carbon hybrids.During carbonization,the N-molecules provide alkane/ammonia gases and the formed iron nanocrystals act as the in situ catalysts,which result in the elaborated formation of carbon nanotubes(in situ chemical vapor deposition from alkane/iron catalysts)and micro-/meso-porous structures(ammonia gas etching).The obtained catalysts exhibited with abundant Fe/Fe-Nx/pyridinic-N active species,micro-/meso-porous structures,and conductive carbon nanotubes.Consequently,the catalysts exhibit high efficiency toward the degradation of different organic pollutions,such as bisphenol A,methylene blue,and tetracycline.This study not only creates a new pathway for achieving highly active Fenton-like carbon catalysts but also takes a step toward the customized production of advanced carbon hybrids for diverse energy and environmental applications.
基金support to visit The University of Adelaide from the China Scholarship Council(No.201906240037).
文摘The sluggish kinetics of Fe(Ⅱ)recovery in Fenton/Fenton-like reactions significantly limits the oxidation efficiency.In this study,we for the first time use boron carbide(BC)as a green and stable promotor to enhance the reaction of Fe(Ⅲ)/H_(2)O_(2) for degradation of diverse organic pollutants.Electron paramagnetic resonance analysis and chemical quenching/capturing experiments demonstrate that hydroxyl radicals(·OH)are the primary reactive species in the BC/Fe(Ⅲ)/H_(2)O_(2) system.In situ electrochemical analysis indicates that BC remarkably boosts the Fe(Ⅲ)/Fe(Ⅱ)redox cycles,where the adsorbed Fe(Ⅲ)cations were transformed to more active Fe(Ⅲ)species with a higher oxidative potential to react with H_(2)O_(2) to produce Fe(Ⅱ).Thus,the recovery of Fe(Ⅱ)from Fe(Ⅲ)is facilitated over BC surface,which enhancesOH generation via Fenton reactions.Moreover,BC exhibits outstanding reusability and stability in successive cycles and avoids the secondary pollution caused by conventional organic and metalliferous promotors.Therefore,metal-free BC boosting Fe(Ⅲ)/H_(2)O_(2) oxidation of organics provides a green and advanced strategy for water decontamination.
基金Project(CZQ13002)supported by the Special Fund for Basic Scientific Research of Central Universities,China
文摘Heterogeneous Fenton-like process using fly ash as a catalyst was studied to degrade n-butyl xanthate form aqueous solution. The different reaction parameters on the degradation efficiency of the process were investigated. The fly ash/H2O2 catalyst possesses a high oxidation activity for n-butyl xanthate degradation in aqueous solution. It is found that both the dosage of catalyst and initial solution pH significantly affect the n-butyl xanthate conversion efficient. The results indicate that by using 1.176 mmol/L H2O2 and 1.0 g/L fly ash catalyst with mass fraction of 4.14% Fe(III) oxide at pH 3.0, almost 96.90% n-butyl xanthate conversion and over 96.66% COD removal can be achieved within 120 min with heterogeneous catalysis by fly ash. CS2 as an intermediate of n-butyl xanthate oxidation. Finally, it is demonstrated that the fly ash/H2O2 catalytic oxidation process can be an efficient method for the treatment of n-butyl xanthate containing wastewater.
文摘Various Cu/ZnO/Al2O3 catalysts have been synthesized by different aluminum emulsions as aluminum sources and their pertormances tor methanol synthesis from syngas have been investigated. The influences of preparation methods of aluminum emulsions on physicochemical and catalytic properties of catalysts were studied by XRD, SEM, XPS,N2 adsorption-desorption techniques and methanol synthesis from syngas. The preparation methods of aluminum emulsions were found to influence the catalytic activity, CuO crystallite size, surface area and Cu0 surface area and reduction process. The results show that the catalyst CN using the aluminum source prepared by addition the ammonia into the aluminum nitrate (NP) exhibited the best catalytic performance for methanol synthesis from syngas.
基金financially supported by the National Natural Science Foundation of China(No.U1810205)the National Basic Research Program of China(No.2014CB 643401)Shanxi Collaborative Innovation Center of High Value-added Utilization of Coal-related Wastes。
文摘Pure metal-doped(Cu,Zn)Fe2O4 was synthesized from Zn-containing electric arc furnace dust(EAFD)by solid-state reaction using copper salt as additive.The effects of pretreated EAFD-to-Cu2(OH)2CO3·6H2O mass ratio,calcination time,and calcination temperature on the structure and catalytic ability were systematically studied.Under the optimum conditions,the decolorization efficiency and total organic carbon(TOC)removal efficiency of the as-prepared ferrite for treating a Rhodamine B solution were approximately 90.0%and 45.0%,respectively,and the decolorization efficiency remained 83.0%after five recycles,suggesting that the as-prepared(Cu,Zn)Fe2O4 was an efficient heterogeneous Fenton-like catalyst with high stability.The high catalytic activity mainly depended on the synergistic effect of iron and copper ions occupying octahedral positions.More importantly,the toxicity characteristic leaching procedure(TCLP)analysis illustrated that the toxic Zncontaining EAFD was transformed into harmless(Cu,Zn)Fe2O4 and that the concentrations of toxic ions in the degraded solution were all lower than the national emission standard(GB/31574-2015),further confirming that the as obtained sample is an environment-friendly heterogeneous Fenton-like catalyst.
基金funding support from National Natural Science Foundation of China(grant No.11674237 and 51602211)National Key Research and Development Program of China(grant No.2016YFB0700700)+2 种基金Natural Science Foundation of Jiangsu Province of China(grant No.BK20160299)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)China Post-doctoral Foundation(grant No.7131705619).
文摘Recently,inorganic copper-based halide perovskites and their derivatives(CHPs)with chemical formulas AlCumXn(A=Rb and Cs;X=Cl,Br and I;l,m,and n are integers.),have received increasing attention in the photoluminescence field,due to their lead-free,cost-effective,earth-abundant and low electronic dimensionality.Ascribed to flexible valence charge of Cu(Cu1+and Cu2+)and complex competing phases,the crystal structures and phase stabilities of CHPs are complicated and ambiguous,which limits their experimental applications.Via comprehensive first-principles calculations,we have investigated thermodynamic stabilities of possible crystal phases for AlCumXn by considering all the possible secondary phases existing in inorganic crystal structure database(ICSD).Our results are in agreement with existing experiments and further predicted the existence of 10 stable CHPs,i.e.Rb3 Cu2 Br5,Rb3 Cu2 I5,Rb Cu2 Cl3,Rb2 Cu I3,Rb2 Cu Br4,Rb Cu Br3,Rb3 Cu2 Br7,Cs3 Cu2 Br7,Cs3 Cu2 Cl7 and Cs4 Cu5 Cl9,which have not yet been reported in experiments.This work provides a phase and compositional map that may guide experiments to synthesize more novel inorganic CHPs with diverse properties for potential functional applications.
基金supported by the National Natural Science Foundation of China(51606087)Start-Up Foundation of Jiangsu University(15JDG157)Foundation of State Key Laboratory of High-efficiency Utilization of Coal and Green Chemical Engineering(2020-KF-07)。
文摘Chemical looping combustion(CLC)is an energy conversion technology with high efficiency and inherent separation of CO_(2).The existence of sulfur in coal may affect the CO_(2) purity and the performance of oxygen carrier due to the interactions between sulfur contaminants and oxygen carrier.The migration of sulfur in Beisu coal during the in-situ gasification chemical looping combustion(i G-CLC)process using two oxygen carriers(iron ore and Cu O/Si O_(2))was investigated respectively.The thermodynamic analysis results showed the formation of metal sulfides was thermodynamically favored at low temperatures and low oxygen excess coefficients,while they were obviously inhibited and the production of SO_(2) was significantly promoted with an increase in temperature and oxygen excess coefficient.Moreover,part of sulfur was captured and fixed in the forms of alkali/alkaline earth metal sulfate due to the high amount of alkali/alkaline earth metal oxides in the coal ash or/and oxygen carrier.The experimental results showed that the sulfur in coal mainly released in the form of SO_(2),and the sulfur conversion efficiency(XS)in the reduction stage were 51.04%and 48.24%when using iron ore and Cu O/Si O_(2) respectively.The existence of metal sulfides was observed in the reduced oxygen carriers.The values of XSin the reoxidation process reached 3.80%and 7.64%when using iron ore and Cu O/Si O_(2) respectively.The residue and accumulation of sulfur were also found on the surfaces of two oxygen carriers.
基金Sponsored by the National High Technology Research and Development Program of China(863 Program) (Grant No.2006AA06Z306)the Natural Science Foundation of China under the Scheme of Innovation Group Fund
文摘During the oxidative degradation of nonbiodegradable Malachite green (MG) by means of H2O2 /FeIIIR (iron supported on ion-exchage resin) in a dynamic column,the binding energy of the Fe(2p3/2) region for XPS spectra was found to be different between the top layer and the bottom layer in this column. Based on the data from XPS spectra and DMPO-OH·signal by EPR spectra,it is shown that the formation of ferryl (IV) is the key step for the oxidation of MG. The ferryl (IV) species can oxidize MG,and its redox potential is about 0. 739 - 0. 803 V measured by cyclic voltammograms (CV) . The catalytic capability of ferryl (IV) species was also evaluated,and it is found that it can promote the decomposition of H2O2 more efficiently than ferric iron. The removal rate of MG mainly depends on the adsorption of catalyst. Both ferryl (IV) and HO·radicals are the reactive species in the system. The oxidation of HO·is only a small part of the overall removal rate. Based on the obtained results,a possible mechanism for a resin-supported Fenton-like oxidation reaction is proposed.
基金Supported by the National Natural Science Foundation of China(21407052)Key Project in the National Science&Technology Pillar Program during the Twelfth Five-year Plan Period(2012BAC02B04)+2 种基金Research Fund for the Doctoral Program of Higher Education of China(201201420087)SRF from ROCS and SEMthe Fundamental Research Funds for the Central Universities(2014QN144)
文摘In this study,a novel magnetically separable adsorbent,molecular imprinting magnetic γ-Fe_2O_3/crosslinked chitosan composites(MIPs),were prepared by a microemulsion process.Adsorption and Fenton-like oxidative degradation of a model pharmaceutical pollutant norfloxacin(NOR) by using MIPs were investigated.Various characterization methods were used to study the properties of MIPs,and it is suggested that the hydroxyl groups are the main adsorption sites for NOR.MIPs present better selective adsorption for NOR than its reference antibiotic sulfadiazine.The NOR adsorption data can be well fitted by Langmuir isotherm model and pseudosecond-order kinetic model.The optimum pH range for NOR adsorption is 7-10.In addition,the MIP-catalyzed Fenton-like system(MIPs/H_2O_2) exhibits remarkably faster removal rate for NOR than the case of γ-Fe_2O_3/H_2O_2.The result indicates that MIPs will be a good functional material in decontamination of pharmaceutical wastewaters since MIPs can be magnetically recycled after the treatment.
基金financially supported by the National Science Fund for Excellent Young Scholars of China (No. 52022111)the Distinguished Young Scholars of China (No. 51825403)the National Natural Science Foundation of China (Nos. 51634010, 51974379)。
文摘Between the two major arsenic-containing salts in natural water, arsenite(As(Ⅲ)) is far more harmful to human and the environment than arsenate(As(V)) due to its high toxicity and transportability. Therefore, preoxidation of As(Ⅲ) to As(V) is considered to be an effective means to reduce the toxicity of arsenic and to promote the removal efficiency of arsenic. Due to their high catalytic activity and arsenic affinity, iron-based functional materials can quickly oxidize As(Ⅲ) to As(V) in heterogeneous Fenton-like systems, and then remove As(V) from water through adsorption and surface coprecipitation. In this review, the effects of different iron-based functional materials such as zero-valent iron and iron(hydroxy) oxides on arsenic removal are compared, and the catalytic oxidation mechanism of As(Ⅲ) in heterogeneous Fenton process is further clarified. Finally, the main challenges and opportunities faced by iron-based As(Ⅲ) oxidation functional materials are prospected.
文摘[Objectives] The effects of copper-based nutrient foliar fertilizer on photosynthetic characteristics,yield,accumulation and distribution of trace elements in various organs,disease prevention effect and soil enzyme activity were studied,so as to provide a theoretical basis for the application of foliar fertilizers in cotton production. [Methods]Through two years of field experiments,six treatments were set in total,namely spraying water( CK),traditional Bordeaux mixture( BDM),Kocide 2000( KCD),copper-based nutrient foliar fertilizer( CF),iron-copper-based nutrient foliar fertilizer( CFFe),and zinc-boron-copper-based nutrient foliar fertilizer( CFZnB). Randomized block arrangement was adopted. Chlorophyll content in leaves was measured at each growth stage of the cotton. Photosynthetic characteristics of leaves were measured at the peak bolling stage. Plants were sampled at initial boll opening stage. The whole plant was divided into root,stem,leaf and cotton boll parts,in which the total copper,total zinc,total iron contents and accumulations were determined. Soil samples were collected from each plot,followed by the determination of soil enzyme activity. Disease index was investigated at bud,flowering and boll-forming and boll opening stage. [Results]( 1) Spraying CFFe,CFZnB,CF and KCD could significantly improve chlorophyll content of cotton leaves,and the CFFe treatment had the highest increase up to13. 30%,followed by the CFZnB treatment,which was 11. 40% higher than the CK; and photosynthetic rate,stomata conductance and transpiration rate could be improved significantly,and the CFFe treatment showed the highest photosynthetic rate,which increased by 26. 35% compared with the CK,followed by the CFZnB treatment,which increased by 17. 96% compared with CK; and intercellular CO2 concentration was significantly reduced.( 2) Spraying BDM,KCD,CF,CFFe and CFZnB can significantly increase total copper content and accumulation in various cotton organs( except the total copper content in the stem part of the CFZnB treatment; the CFZnB and CFFe treatments can significantly increase total zinc content and accumulation in various cotton organs; and spraying CFFe,CFZnB and CF can significantly increase total iron content and accumulation in various cotton organs( except the total iron content in the stem part of the CF treatment).( 3)Spraying CFFe,CFZnB,CF,KCD and BDM greatly reduced the disease index at flowering and boll-forming and boll opening stages.( 4) The CFZnB and CFFe treatments had the highest soil urease activity,which was 7. 14% higher than that of the CK,but the difference from the CK was not significant; the catalase activity of each treatment was significantly higher than that of the BDM treatment; and the sucrase activity of each treatment was significantly higher than that of the CK.( 5) Spraying CFFe,CFZnB,CF and KCD significantly improved lint yield of cotton,and the CFZnB treatment showed the highest yield increase up to 12. 34%,followed by the CFFe treatment,with an increase in the range of 8. 77%-10. 20%. [Conclusions]Copper-based nutrient foliar fertilizers have dual functions of disease control and prevention and plant nutrition and health care,and not only can significantly increase cotton yield,but also has certain disease prevention effect.It is recommended to use copper-based nutrient foliar fertilizers.