In this study,a Fe,N-decorated carbocatalyst(FeCN@X)based on Fe-MOFs was synthesized to activate peroxydisulfate(PDS)for removing sulfadiazine(SDZ)from water.The surface morphology and structure of FeCN@X was characte...In this study,a Fe,N-decorated carbocatalyst(FeCN@X)based on Fe-MOFs was synthesized to activate peroxydisulfate(PDS)for removing sulfadiazine(SDZ)from water.The surface morphology and structure of FeCN@X was characterized by scanning electron microscopy,X-ray diffraction,and X-ray photoelectron spec troscopy.FeCN@1000,formed at the pyrolysis temperature of 1000℃,exhibited the best catalytic performance for degrade SDZ in the presence of 0.15 g·L^(-1)catalyst and 0.5 mmol·L^(-1)PDS,and the reaction conversion rate was 0.199 L·mmol^(-1).Moreover,the effects of experimental conditions,coexisting anions and fulvic acid on catalytic performance of FeCN@1000 were investigated.The excellent potential of FeCN@1000 as a PDS activator in environmental applications was also suggested by the results of its reusability and adaptability experiments.The result of XPS,ROS quenching,EPR and electrochemical experiments showed the degradation of SDZ was primarily driven by an electron transfer process(ETP).Furthermore,Fe(Ⅲ)instead of Fe(Ⅱ)plays a major role in ETP,as Fe(Ⅲ)sites can interact with PDS and form the low-spin surface complexes(Fe(Ⅲ)/CN-PDS).Meanwhile,the small number of~1O_(2) and O_(2)~-·generated by the activation of PDS will promote the system degradation of SDZ activity by accelerating the conversion of Fe(Ⅱ)to Fe(Ⅲ).This study provides new insights for the design of novel PDS activator for efficient degradation of emerging pollutants by ETP.展开更多
Nanoscale graphene oxide(NGO)sheets were synthesized and used as carbocatalysts for effectiveoxidation of benzylic alcohols and aromatic aldehydes.For oxidation of alcohols in the presence ofH2O2at80°C,the NGOs(2...Nanoscale graphene oxide(NGO)sheets were synthesized and used as carbocatalysts for effectiveoxidation of benzylic alcohols and aromatic aldehydes.For oxidation of alcohols in the presence ofH2O2at80°C,the NGOs(20%mass fraction)as carbocatalysts showed selectivity toward aldehyde.The rate and yield of this reaction strongly depended on the nature of substituents on the alcohol.For4‐nitrobenzyl alcohol,<10%of it was converted into the corresponding carboxylic acid after24h.By contrast,4‐methoxybenzyl alcohol and diphenylmethanol were completely converted into thecorresponding carboxylic acid and ketone after only9and3h,respectively.The conversion ratesfor oxidation of aromatic aldehydes by NGO carbocatalysts were higher than those for alcohol oxidation.For all the aldehydes,complete conversion to the corresponding carboxylic acids wasachieved using7%(mass fraction)of NGO at70°C within2–3h.Possible mechanisms for NGOcarbocatalyst structure‐dependent oxidation of benzyl alcohols and structure‐independent oxidationof aromatic aldehydes are discussed.展开更多
The development of an active, durable, and metal-free carbocatalyst that is able to replace metal-based catalysts is of increasing scientific and technological importance. The use of such a catalyst would avoid proble...The development of an active, durable, and metal-free carbocatalyst that is able to replace metal-based catalysts is of increasing scientific and technological importance. The use of such a catalyst would avoid problems caused by metal- containing catalysts, for example, environmental pollution by heavy metals and depletion of rare metal resources. Herein, an active and durable graphene carbocatalyst is presented for the carbocatalytic conversion of 4-nitrophenol to 4-aminophenol at ambient temperature. The carbocatalyst was prepared via a mild, water-based reaction between L-ascorbic acid （AA） and graphene oxide （GO） and did not involve any other reactants. During the structure and catalytic property optimization, a series of carbocatalysts were fabricated at various reaction temperatures and AA/GO ratios. Using several characterization techniques, detailed structural features of these carbocatalysts were identified. Possible active species and sites on the carbocatalysts were also identified such as certain oxygen-containing groups, the ~x-conjugated system, and graphene sheet edges. In addition, the synergistic effect between these active species and sites on the resulting catalytic activity is highlighted. Furthermore, we clarified the origin of the high stability and durability of the optimized carbocatalyst. The work presented here aids the design of high-performance carbocatalysts for hydrogenation reactions, and increases understanding of the structural and mechanistic aspects at the molecular level that lead to high catalyst activity and durability.展开更多
This study has introduced a pioneering methodology by employing biochars as a basic carbocatalyst in the context of multicomponent reactions.Biochars were produced from different manures and organic wastes using the p...This study has introduced a pioneering methodology by employing biochars as a basic carbocatalyst in the context of multicomponent reactions.Biochars were produced from different manures and organic wastes using the pyrolysiscarbonization process under limited oxygen conditions.The prepared biochars were well characterized using Fourier transform infrared spectroscopy(FT-IR),scanning electron microscopy(SEM),energy-dispersive X-ray spectroscopy(EDX),Brunauer-Emmett-Teller(BET)analysis,and powder X-ray diffraction(XRD).The chemical characteristics and potentiometric titration analysis provide compelling evidence of the intriguing basicity properties exhibited by the prepared biochars.The pH values,ash content,and potentiometric titration results confirmed the exceptional basicity characteristics of cow manure biochar formed at 600 oC(CB600),establishing it as the most basic carbocatalyst in this study.Encouraged by these initial results,the activity of the biochars as basic carbocatalysts was evaluated in multicomponent synthesis of 4H-benzo[h]chromene and pyranopyrazoles and 600°C exhibited the most pronounced catalytic performance owing to its superior total basicity.By these findings,it can be asserted that this work introduces the groundbreaking application of biochars as potent basic carbocatalysts for the multicomponent synthesis of structurally diverse heterocycles.Unveiling the vital basic role of biochars will definitely open up new opportunities in organic chemistry and provide salient features for environmentally-friendly chemistry,including easy retrieval,non-toxicity,and widespread accessibility.展开更多
Advanced oxidation processes(AOPs)governed by peroxide activation to produce highly oxidative active species have been extensively explored for environmental remediation.Nevertheless,the low diffusion rates,inadequate...Advanced oxidation processes(AOPs)governed by peroxide activation to produce highly oxidative active species have been extensively explored for environmental remediation.Nevertheless,the low diffusion rates,inadequate interactions of the reactants,and limited active site exposure hinder treatment efficiency.Porous carbocatalysts with high specific surface area,tunable pore size,and programmable active sites demonstrate outstanding performance in activating diverse types of peroxides to generate active species for treatment of aqueous organic pollutants.The pore-rich structures enhance reaction kinetics for peroxide activation by facilitating diffusion of the reactants and their interactions.Additionally,the structural flexibility of porous structures favors the accommodation of highly dispersed metal species and allows for precise tuning of the microenvironment around the active sites,which further enhances the catalytic activity.This review critically summarizes the recent research progress in the applications of engineered porous carbocatalysts for peroxide activation and outlines the prevailing pore construction methods in carbocatalysts.Moreover,engineering strategies to regulate the mass transfer efficiency and fine-tune the microenvironment around the active sites are systematically addressed to enhance their catalytic peroxide activation performances.Challenges and future research opportunities pertaining to the design,optimization,mechanistic investigation,and practical application of porous carbocatalysts in peroxide activation are also proposed.展开更多
Nitrogen-rich graphitized carbon microspheres(NGCs)with hierarchically porous were constructed by self-assembly.Under different heat treatment conditions,the structure,morphology and properties of NGCs were studied by...Nitrogen-rich graphitized carbon microspheres(NGCs)with hierarchically porous were constructed by self-assembly.Under different heat treatment conditions,the structure,morphology and properties of NGCs were studied by using multiple characterization techniques.The results showed that the chemical microenvironments(e.g.surface chemistry,degree of graphitization and defective,etc.)and microstructures properties(e.g.morphology,specific surface area,particle size,etc.)could be delicately controlled via thermal carbonization processes.The degradation of ofloxacin(OFLX)by NGCs activated peroxymonosulfate(PMS)was studied systematically.It was found that the synergistic coupling effect between optimum N or O bonding species configuration ratio(graphitic N and C=O)and special microstructure was the main reason for the enhanced catalytic activity of NGC-800(calcination temperature at 800°C).Electron paramagnetic resonance(EPR)experiments and radical quenching experiments indicated that the hydroxyl(·OH),sulfate(SO4^·-)and singlet oxygen(^1O_(2))were contributors in the NGC-800/PMS systems.Further investigation of the durability of chemical structures and surface active sites revealed that undergo N bonding species configuration reconstruction and cannibalistic oxidation during PMS activation reaction.The used NGC-800 physicochemical properties could be recovered by heat treatment to achieve the ideal catalytic performance.The findings proposed a valuable insight for catalytic performance and controllable design of construction.展开更多
Graphene oxide(GO),as a metal-free and readily available carbocatalyst,has been extensively applied in catalytic organic transformations.This minireview aims to give an overview of the progress on the application of n...Graphene oxide(GO),as a metal-free and readily available carbocatalyst,has been extensively applied in catalytic organic transformations.This minireview aims to give an overview of the progress on the application of native GO as a catalyst for various organic transformations in the past decade(mainly from 2011 to 2020).展开更多
基金supported by Key Research and Development Projects of Shanghai Municipal Commission of Science and Technology(20dz1204000)。
文摘In this study,a Fe,N-decorated carbocatalyst(FeCN@X)based on Fe-MOFs was synthesized to activate peroxydisulfate(PDS)for removing sulfadiazine(SDZ)from water.The surface morphology and structure of FeCN@X was characterized by scanning electron microscopy,X-ray diffraction,and X-ray photoelectron spec troscopy.FeCN@1000,formed at the pyrolysis temperature of 1000℃,exhibited the best catalytic performance for degrade SDZ in the presence of 0.15 g·L^(-1)catalyst and 0.5 mmol·L^(-1)PDS,and the reaction conversion rate was 0.199 L·mmol^(-1).Moreover,the effects of experimental conditions,coexisting anions and fulvic acid on catalytic performance of FeCN@1000 were investigated.The excellent potential of FeCN@1000 as a PDS activator in environmental applications was also suggested by the results of its reusability and adaptability experiments.The result of XPS,ROS quenching,EPR and electrochemical experiments showed the degradation of SDZ was primarily driven by an electron transfer process(ETP).Furthermore,Fe(Ⅲ)instead of Fe(Ⅱ)plays a major role in ETP,as Fe(Ⅲ)sites can interact with PDS and form the low-spin surface complexes(Fe(Ⅲ)/CN-PDS).Meanwhile,the small number of~1O_(2) and O_(2)~-·generated by the activation of PDS will promote the system degradation of SDZ activity by accelerating the conversion of Fe(Ⅱ)to Fe(Ⅲ).This study provides new insights for the design of novel PDS activator for efficient degradation of emerging pollutants by ETP.
文摘Nanoscale graphene oxide(NGO)sheets were synthesized and used as carbocatalysts for effectiveoxidation of benzylic alcohols and aromatic aldehydes.For oxidation of alcohols in the presence ofH2O2at80°C,the NGOs(20%mass fraction)as carbocatalysts showed selectivity toward aldehyde.The rate and yield of this reaction strongly depended on the nature of substituents on the alcohol.For4‐nitrobenzyl alcohol,<10%of it was converted into the corresponding carboxylic acid after24h.By contrast,4‐methoxybenzyl alcohol and diphenylmethanol were completely converted into thecorresponding carboxylic acid and ketone after only9and3h,respectively.The conversion ratesfor oxidation of aromatic aldehydes by NGO carbocatalysts were higher than those for alcohol oxidation.For all the aldehydes,complete conversion to the corresponding carboxylic acids wasachieved using7%(mass fraction)of NGO at70°C within2–3h.Possible mechanisms for NGOcarbocatalyst structure‐dependent oxidation of benzyl alcohols and structure‐independent oxidationof aromatic aldehydes are discussed.
文摘The development of an active, durable, and metal-free carbocatalyst that is able to replace metal-based catalysts is of increasing scientific and technological importance. The use of such a catalyst would avoid problems caused by metal- containing catalysts, for example, environmental pollution by heavy metals and depletion of rare metal resources. Herein, an active and durable graphene carbocatalyst is presented for the carbocatalytic conversion of 4-nitrophenol to 4-aminophenol at ambient temperature. The carbocatalyst was prepared via a mild, water-based reaction between L-ascorbic acid （AA） and graphene oxide （GO） and did not involve any other reactants. During the structure and catalytic property optimization, a series of carbocatalysts were fabricated at various reaction temperatures and AA/GO ratios. Using several characterization techniques, detailed structural features of these carbocatalysts were identified. Possible active species and sites on the carbocatalysts were also identified such as certain oxygen-containing groups, the ~x-conjugated system, and graphene sheet edges. In addition, the synergistic effect between these active species and sites on the resulting catalytic activity is highlighted. Furthermore, we clarified the origin of the high stability and durability of the optimized carbocatalyst. The work presented here aids the design of high-performance carbocatalysts for hydrogenation reactions, and increases understanding of the structural and mechanistic aspects at the molecular level that lead to high catalyst activity and durability.
基金The research leading to these results received funding from Shiraz University(Grant No.0GRC1M235307).
文摘This study has introduced a pioneering methodology by employing biochars as a basic carbocatalyst in the context of multicomponent reactions.Biochars were produced from different manures and organic wastes using the pyrolysiscarbonization process under limited oxygen conditions.The prepared biochars were well characterized using Fourier transform infrared spectroscopy(FT-IR),scanning electron microscopy(SEM),energy-dispersive X-ray spectroscopy(EDX),Brunauer-Emmett-Teller(BET)analysis,and powder X-ray diffraction(XRD).The chemical characteristics and potentiometric titration analysis provide compelling evidence of the intriguing basicity properties exhibited by the prepared biochars.The pH values,ash content,and potentiometric titration results confirmed the exceptional basicity characteristics of cow manure biochar formed at 600 oC(CB600),establishing it as the most basic carbocatalyst in this study.Encouraged by these initial results,the activity of the biochars as basic carbocatalysts was evaluated in multicomponent synthesis of 4H-benzo[h]chromene and pyranopyrazoles and 600°C exhibited the most pronounced catalytic performance owing to its superior total basicity.By these findings,it can be asserted that this work introduces the groundbreaking application of biochars as potent basic carbocatalysts for the multicomponent synthesis of structurally diverse heterocycles.Unveiling the vital basic role of biochars will definitely open up new opportunities in organic chemistry and provide salient features for environmentally-friendly chemistry,including easy retrieval,non-toxicity,and widespread accessibility.
基金supports from the National Natural Science Foundation of China(Nos.22478426 and 22278436)Young Elite Scientists Sponsorship Program by BAST(No.1101020370359)Science Foundation of China University of Petroleum,Beijing(No.2462021QNXZ009)。
文摘Advanced oxidation processes(AOPs)governed by peroxide activation to produce highly oxidative active species have been extensively explored for environmental remediation.Nevertheless,the low diffusion rates,inadequate interactions of the reactants,and limited active site exposure hinder treatment efficiency.Porous carbocatalysts with high specific surface area,tunable pore size,and programmable active sites demonstrate outstanding performance in activating diverse types of peroxides to generate active species for treatment of aqueous organic pollutants.The pore-rich structures enhance reaction kinetics for peroxide activation by facilitating diffusion of the reactants and their interactions.Additionally,the structural flexibility of porous structures favors the accommodation of highly dispersed metal species and allows for precise tuning of the microenvironment around the active sites,which further enhances the catalytic activity.This review critically summarizes the recent research progress in the applications of engineered porous carbocatalysts for peroxide activation and outlines the prevailing pore construction methods in carbocatalysts.Moreover,engineering strategies to regulate the mass transfer efficiency and fine-tune the microenvironment around the active sites are systematically addressed to enhance their catalytic peroxide activation performances.Challenges and future research opportunities pertaining to the design,optimization,mechanistic investigation,and practical application of porous carbocatalysts in peroxide activation are also proposed.
基金the National Natural Science Foundation of China(No.51578295)the National Natural Science Foundation of Jiangsu Province(No.BK20161479)+3 种基金Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse(Nanjing University of Science and Technology)Qinglan Project of Jiangsu Province supported this studyFoundation of Jiangsu Collaborative Innovation Center of Biomedical Functional Materialsa project funded by the priority academic program development of Jiangsu Higher Education Institutions。
文摘Nitrogen-rich graphitized carbon microspheres(NGCs)with hierarchically porous were constructed by self-assembly.Under different heat treatment conditions,the structure,morphology and properties of NGCs were studied by using multiple characterization techniques.The results showed that the chemical microenvironments(e.g.surface chemistry,degree of graphitization and defective,etc.)and microstructures properties(e.g.morphology,specific surface area,particle size,etc.)could be delicately controlled via thermal carbonization processes.The degradation of ofloxacin(OFLX)by NGCs activated peroxymonosulfate(PMS)was studied systematically.It was found that the synergistic coupling effect between optimum N or O bonding species configuration ratio(graphitic N and C=O)and special microstructure was the main reason for the enhanced catalytic activity of NGC-800(calcination temperature at 800°C).Electron paramagnetic resonance(EPR)experiments and radical quenching experiments indicated that the hydroxyl(·OH),sulfate(SO4^·-)and singlet oxygen(^1O_(2))were contributors in the NGC-800/PMS systems.Further investigation of the durability of chemical structures and surface active sites revealed that undergo N bonding species configuration reconstruction and cannibalistic oxidation during PMS activation reaction.The used NGC-800 physicochemical properties could be recovered by heat treatment to achieve the ideal catalytic performance.The findings proposed a valuable insight for catalytic performance and controllable design of construction.
基金support from the National Natu-ral Science Foundation of China(Nos.21971224,22171249)the Natural Science Foundation of Henan Province(No.202300410375).
文摘Graphene oxide(GO),as a metal-free and readily available carbocatalyst,has been extensively applied in catalytic organic transformations.This minireview aims to give an overview of the progress on the application of native GO as a catalyst for various organic transformations in the past decade(mainly from 2011 to 2020).
