Nitrogen-doped carbon(N-C)materials have demonstrated exceptional performances in activating peroxymonosulfate(PMS)for environmental remediation.However,accommodating higher nitrogen contents remains challenging in N-...Nitrogen-doped carbon(N-C)materials have demonstrated exceptional performances in activating peroxymonosulfate(PMS)for environmental remediation.However,accommodating higher nitrogen contents remains challenging in N-C due to the thermodynamic instability of C-N skeleton.In this study,we proposed an innovative epitaxial growth approach to synthesize two-dimensional N-C nanosheets.Leveraging the abundant amino groups supplied by the polymer dots as growing sites,we successfully attained a high nitrogen level and spontaneously introduced abundant structural defects in the carbon framework.The resulting N-C nanosheets exhibited outstanding catalytic activity for the activation of PMS toward selective oxidation of diethyl 1,4-dihydro-2,6-dimethyl-3,5-pyridinedicarboxylate(1,4-DHP)into diethyl2,6-dimethylpyridine-3,5-dicarboxylate,which serves as a valuable intermediate in the synthesis of various pharmaceutical compounds.Comprehensive experimental and characterization investigations verified that the nitrogen sites and defects are the primary active sites for PMS activation and selective oxidation of 1,4-DHP.This work offered an efficient approach for the fabrication of high-nitrogen-loading carbon materials for catalytic oxidation reactions.展开更多
Herein,a diatomite biomorphic Si-O doped carbon-based catalyst(DB-SiOC)was prepared using natura mineral diatomite as the silicon source and porous template.The results showed that the metal-free DB SiOC catalyst exhi...Herein,a diatomite biomorphic Si-O doped carbon-based catalyst(DB-SiOC)was prepared using natura mineral diatomite as the silicon source and porous template.The results showed that the metal-free DB SiOC catalyst exhibited ultrafast oxidation towards chlorophenol(CP)via peroxymonosulfate(PMS)activa tion,which was almost one order of magnitudes than most of carbon-based catalysts.The DB-SiOC/PMS system also showed the high ability to resist the interference of environmental matrix.The radicals(^(·)OH and SO_(4)^(·–))exhibited a very small contribution to the CP oxidation while the electron transfer processe(ETP)played the major role in the DB-SiOC/PMS system.The electron shuttles from the electron-donating CP molecules to the adjacent DB-SiOC/PMS^(*)could be efficiently triggered via Si-O bonds as bridges,mak ing it possible for ultrafast oxidation of CP.In addition,the hollow-disc shaped DB-Si OC provided the biomorphic DE structures with abundant pores for enriching the PMS and pollutants,thus further ac celerating the oxidation reaction.This work provided a new routine for the fabrication of Si-O doped carbon-based catalysts with excellent Fenton-like catalytic activity,which would greatly promote thei application prospects in Fenton-like systems.展开更多
Electron-transfer processes facilitated by hydrophobic-lipophilic interaction (HLI) between excited N-alkylcarbazoles (1-n, n = 4, 8, 12, 16) as electron donors and 2,4-dinitrophenyl carboxylates (2-n, n = 4, 8, 12, 1...Electron-transfer processes facilitated by hydrophobic-lipophilic interaction (HLI) between excited N-alkylcarbazoles (1-n, n = 4, 8, 12, 16) as electron donors and 2,4-dinitrophenyl carboxylates (2-n, n = 4, 8, 12, 16) or pentafluorophenyl carboxylates (3-n, n = 4, 8, 12, 16) as electron acceptors have been investigated by means of fluorescence spectroscopy in aqueous or aquiorgano binary mixtures. The fluorescence quenching of -n* by 2-n or - n indicates that preassociation precedes the electron transfer. The extent of HLI-driven coaggregation of the acceptor and the donor may be assessed from the B value of the equation I0/I = A + B [Q]. The chain-length effect and possibly also a chain-fold-ability effect, as well as the solvent aggregating power (SAgP) effect have been observed. Comparison of roe quenching constants (B) for 1-n*/2-n combinations and 1-n*/ 3-n combinations shows that the order of increasing B values for the quenching processes is 3-n < 2-n.展开更多
Comprehensive Summary Cathode interlayers(CILs)play an essential role in achieving efficient organic solar cells(OSCs).However,the electronic structure at the electrode/CIL/active layer interfaces and the underlying m...Comprehensive Summary Cathode interlayers(CILs)play an essential role in achieving efficient organic solar cells(OSCs).However,the electronic structure at the electrode/CIL/active layer interfaces and the underlying mechanisms for electron collection remain unclear,which becomes a major obstacle to develop high-performance CILs.Herein,we investigate the relationship of the electron collection abilities of four cross-linked and n-doped CILs(c-NDI:P0,c-NDI:P1,c-NDI:P2,c-NDI:P3)with their electronic structure of space charge region at heterojunction interface.By accurately calculating the depletion region width according to the barrier height,doping density and permittivity,we put forward that the optimal thickness of CIL should be consistent with the depletion region width to realize the minimum energy loss.As a result,the depletion region width is largely reduced from 13 nm to 0.8 nm at the indium tin oxide(ITO)/c-NDI:P0 interface,resulting in a decent PCE of 17.7%for the corresponding inverted OSCs.展开更多
The residual of oxidant chemicals in advanced oxidation processes(AOPs)resulted in both economic cost and secondary pollution.Herein,we report a direct oxidation of phenolic pollutants induced by Ca-Mn-O perovskites w...The residual of oxidant chemicals in advanced oxidation processes(AOPs)resulted in both economic cost and secondary pollution.Herein,we report a direct oxidation of phenolic pollutants induced by Ca-Mn-O perovskites without using an oxidant.Governed by one-electron transfer process(ETP)from the phenolics to the Ca-Mn-O perovskites,this direct oxidation proceeds in fast reaction kinetics with activation energy of 51.4 kJ/mol,which was comparable with those AOPs-based catalytic systems.Additionally,mineralization and polymerization reactions occurred on the Ca-Mn-O surface and ensured the complete removal of phenolics.The high spin state Mn(III)within Ca-Mn-O structure was the dominant active site for this ETP.The elongated axial Mn(III)–O bonds within the[MnO_(6)]octahedron facilitated the acceptance of the electrons from the phenolics and thus promoted the initiation of the direct oxidation process.Mn(III)in the high spin state can also activate dissolved O_(2)to produce singlet oxygen(^(1)O_(2))for a fast removal of phenolics.The mixed Mn(III)/Mn(IV)within Ca-Mn-O accelerated the ETP by enhancing the electrical conductivity.This efficient Ca-Mn-O-induced ETP for removal of organic contaminants casts off the dependence on external chemical and energy inputs and provides a sustainable approach for transforming the toxic organic pollutants into value-added polymers.展开更多
The photo-induced electron transfer reactions of anthracene with N,N -diethylaniline(DEA) and phenothiazine(PTZ) occur in the membrane phase of a Triton X-100/ n -C 10 H 21 OH(1-decanol)/H 2O microemulsion. DEA and PT...The photo-induced electron transfer reactions of anthracene with N,N -diethylaniline(DEA) and phenothiazine(PTZ) occur in the membrane phase of a Triton X-100/ n -C 10 H 21 OH(1-decanol)/H 2O microemulsion. DEA and PTZ exist in the membrane phase of the microemulsion. Anthracene exists in the oil continuous phase of the W/O microemulsion and in the oil core and membrane phase of the O/W microemulsion.展开更多
The electrochemical carbon dioxide reduction reaction(CO_(2)RR),which can produce value-added chemical feedstocks,is a proton-coupled-electron process with sluggish kinetics.Thus,highly efficient,cheap catalysts are u...The electrochemical carbon dioxide reduction reaction(CO_(2)RR),which can produce value-added chemical feedstocks,is a proton-coupled-electron process with sluggish kinetics.Thus,highly efficient,cheap catalysts are urgently required.Transition metal oxides such as CoO_(x),FeO_(x),and NiO_(x)are low-cost,low toxicity,and abundant materials for a wide range of electrochemical reactions,but are almost inert for CO_(2)RR.Here,we report for the first time that nitrogen doped carbon nanotubes(N-CNT)have a surprising activation effect on the activity and selectivity of transition metal-oxide(MO_(x)where M=Fe,Ni,and Co)nanoclusters for CO_(2)RR.MO_(x)supported on N-CNT,MO_(x)/N-CNT,achieves a CO yield of 2.6–2.8 mmol cm−2 min−1 at an overpotential of−0.55 V,which is two orders of magnitude higher than MO_(x)supported on acid treated CNTs(MO_(x)/O-CNT)and four times higher than pristine N-CNT.The faraday efficiency for electrochemical CO_(2)-to-CO conversion is as high as 90.3%at overpotential of 0.44 V.Both in-situ XAS measurements and DFT calculations disclose that MO_(x)nanoclusters can be hydrated in CO_(2)saturated KHCO_(3),and the N defects of N-CNT effectively stabilize these metal hydroxyl species under carbon dioxide reduction reaction conditions,which can split the water molecules and provide local protons to inhibit the poisoning of active sites under carbon dioxide reduction reaction conditions.展开更多
基金the financial support from Australian Research Council under DECRA Scheme(No.DE210100253)merit SXR beamline from Australian Nuclear Science and Technology Organization(ANSTO,No.AS231/SXR/19680)。
文摘Nitrogen-doped carbon(N-C)materials have demonstrated exceptional performances in activating peroxymonosulfate(PMS)for environmental remediation.However,accommodating higher nitrogen contents remains challenging in N-C due to the thermodynamic instability of C-N skeleton.In this study,we proposed an innovative epitaxial growth approach to synthesize two-dimensional N-C nanosheets.Leveraging the abundant amino groups supplied by the polymer dots as growing sites,we successfully attained a high nitrogen level and spontaneously introduced abundant structural defects in the carbon framework.The resulting N-C nanosheets exhibited outstanding catalytic activity for the activation of PMS toward selective oxidation of diethyl 1,4-dihydro-2,6-dimethyl-3,5-pyridinedicarboxylate(1,4-DHP)into diethyl2,6-dimethylpyridine-3,5-dicarboxylate,which serves as a valuable intermediate in the synthesis of various pharmaceutical compounds.Comprehensive experimental and characterization investigations verified that the nitrogen sites and defects are the primary active sites for PMS activation and selective oxidation of 1,4-DHP.This work offered an efficient approach for the fabrication of high-nitrogen-loading carbon materials for catalytic oxidation reactions.
基金supported by National Natural Science Foundation of China(No.52170086)Shandong Provincial Excellent Youth(No.ZR2022YQ47)。
文摘Herein,a diatomite biomorphic Si-O doped carbon-based catalyst(DB-SiOC)was prepared using natura mineral diatomite as the silicon source and porous template.The results showed that the metal-free DB SiOC catalyst exhibited ultrafast oxidation towards chlorophenol(CP)via peroxymonosulfate(PMS)activa tion,which was almost one order of magnitudes than most of carbon-based catalysts.The DB-SiOC/PMS system also showed the high ability to resist the interference of environmental matrix.The radicals(^(·)OH and SO_(4)^(·–))exhibited a very small contribution to the CP oxidation while the electron transfer processe(ETP)played the major role in the DB-SiOC/PMS system.The electron shuttles from the electron-donating CP molecules to the adjacent DB-SiOC/PMS^(*)could be efficiently triggered via Si-O bonds as bridges,mak ing it possible for ultrafast oxidation of CP.In addition,the hollow-disc shaped DB-Si OC provided the biomorphic DE structures with abundant pores for enriching the PMS and pollutants,thus further ac celerating the oxidation reaction.This work provided a new routine for the fabrication of Si-O doped carbon-based catalysts with excellent Fenton-like catalytic activity,which would greatly promote thei application prospects in Fenton-like systems.
文摘Electron-transfer processes facilitated by hydrophobic-lipophilic interaction (HLI) between excited N-alkylcarbazoles (1-n, n = 4, 8, 12, 16) as electron donors and 2,4-dinitrophenyl carboxylates (2-n, n = 4, 8, 12, 16) or pentafluorophenyl carboxylates (3-n, n = 4, 8, 12, 16) as electron acceptors have been investigated by means of fluorescence spectroscopy in aqueous or aquiorgano binary mixtures. The fluorescence quenching of -n* by 2-n or - n indicates that preassociation precedes the electron transfer. The extent of HLI-driven coaggregation of the acceptor and the donor may be assessed from the B value of the equation I0/I = A + B [Q]. The chain-length effect and possibly also a chain-fold-ability effect, as well as the solvent aggregating power (SAgP) effect have been observed. Comparison of roe quenching constants (B) for 1-n*/2-n combinations and 1-n*/ 3-n combinations shows that the order of increasing B values for the quenching processes is 3-n < 2-n.
基金financial support from Guangdong Major Project of Basic and Applied Basic Research(No.2019B030302007)Bureau of International Cooperation Chinese Academy of Sciences(121111KYSB20200043)+1 种基金National Natural Science Foundation of China(NSFC,21835006,51961135103)B.X.would like to acknowledge the financial support from Fundamental Research Funds for the Central Universities(buctrc202140).
文摘Comprehensive Summary Cathode interlayers(CILs)play an essential role in achieving efficient organic solar cells(OSCs).However,the electronic structure at the electrode/CIL/active layer interfaces and the underlying mechanisms for electron collection remain unclear,which becomes a major obstacle to develop high-performance CILs.Herein,we investigate the relationship of the electron collection abilities of four cross-linked and n-doped CILs(c-NDI:P0,c-NDI:P1,c-NDI:P2,c-NDI:P3)with their electronic structure of space charge region at heterojunction interface.By accurately calculating the depletion region width according to the barrier height,doping density and permittivity,we put forward that the optimal thickness of CIL should be consistent with the depletion region width to realize the minimum energy loss.As a result,the depletion region width is largely reduced from 13 nm to 0.8 nm at the indium tin oxide(ITO)/c-NDI:P0 interface,resulting in a decent PCE of 17.7%for the corresponding inverted OSCs.
基金the National Natural Science Foundation of China(Nos.21978324 and 22278436)the Science Foundation of China University of Petroleum,Beijing(No.2462021QNXZ009).
文摘The residual of oxidant chemicals in advanced oxidation processes(AOPs)resulted in both economic cost and secondary pollution.Herein,we report a direct oxidation of phenolic pollutants induced by Ca-Mn-O perovskites without using an oxidant.Governed by one-electron transfer process(ETP)from the phenolics to the Ca-Mn-O perovskites,this direct oxidation proceeds in fast reaction kinetics with activation energy of 51.4 kJ/mol,which was comparable with those AOPs-based catalytic systems.Additionally,mineralization and polymerization reactions occurred on the Ca-Mn-O surface and ensured the complete removal of phenolics.The high spin state Mn(III)within Ca-Mn-O structure was the dominant active site for this ETP.The elongated axial Mn(III)–O bonds within the[MnO_(6)]octahedron facilitated the acceptance of the electrons from the phenolics and thus promoted the initiation of the direct oxidation process.Mn(III)in the high spin state can also activate dissolved O_(2)to produce singlet oxygen(^(1)O_(2))for a fast removal of phenolics.The mixed Mn(III)/Mn(IV)within Ca-Mn-O accelerated the ETP by enhancing the electrical conductivity.This efficient Ca-Mn-O-induced ETP for removal of organic contaminants casts off the dependence on external chemical and energy inputs and provides a sustainable approach for transforming the toxic organic pollutants into value-added polymers.
基金Supported by the National Natural Science Foundation of China( No.2 0 0 730 38,2 0 2 330 10 )
文摘The photo-induced electron transfer reactions of anthracene with N,N -diethylaniline(DEA) and phenothiazine(PTZ) occur in the membrane phase of a Triton X-100/ n -C 10 H 21 OH(1-decanol)/H 2O microemulsion. DEA and PTZ exist in the membrane phase of the microemulsion. Anthracene exists in the oil continuous phase of the W/O microemulsion and in the oil core and membrane phase of the O/W microemulsion.
基金Y.C.and J.C.are contributed equally to the paper.Project supported by the National Natural Science Foundation of China (U19A2017)the Fundamental Research Funds for the Central South University and the Australian Research Council (DP180100731 and DP180100568)。
文摘The electrochemical carbon dioxide reduction reaction(CO_(2)RR),which can produce value-added chemical feedstocks,is a proton-coupled-electron process with sluggish kinetics.Thus,highly efficient,cheap catalysts are urgently required.Transition metal oxides such as CoO_(x),FeO_(x),and NiO_(x)are low-cost,low toxicity,and abundant materials for a wide range of electrochemical reactions,but are almost inert for CO_(2)RR.Here,we report for the first time that nitrogen doped carbon nanotubes(N-CNT)have a surprising activation effect on the activity and selectivity of transition metal-oxide(MO_(x)where M=Fe,Ni,and Co)nanoclusters for CO_(2)RR.MO_(x)supported on N-CNT,MO_(x)/N-CNT,achieves a CO yield of 2.6–2.8 mmol cm−2 min−1 at an overpotential of−0.55 V,which is two orders of magnitude higher than MO_(x)supported on acid treated CNTs(MO_(x)/O-CNT)and four times higher than pristine N-CNT.The faraday efficiency for electrochemical CO_(2)-to-CO conversion is as high as 90.3%at overpotential of 0.44 V.Both in-situ XAS measurements and DFT calculations disclose that MO_(x)nanoclusters can be hydrated in CO_(2)saturated KHCO_(3),and the N defects of N-CNT effectively stabilize these metal hydroxyl species under carbon dioxide reduction reaction conditions,which can split the water molecules and provide local protons to inhibit the poisoning of active sites under carbon dioxide reduction reaction conditions.
