S-scheme heterojunctions have gained widespread application in photocatalytic reactions due to their dis-tinctive carrier transport mechanism and remarkable redox capabilities.However,a significant challenge persists ...S-scheme heterojunctions have gained widespread application in photocatalytic reactions due to their dis-tinctive carrier transport mechanism and remarkable redox capabilities.However,a significant challenge persists in extending carrier lifetimes while simultaneously enhancing light absorption,both of which are essential for optimizing photocatalytic activity.Herein,we report the solvothermal synthesis of ul-trathin CdS nanosheets grown in situ on two-dimensional(2D)Ni-MOF to construct 2D/2D S-scheme heterojunctions.Comprehensive characterizations reveal that the incorporation of Ni-MOF(metal-organic framework)with ligand-to-metal charge transfer(LMCT)states not only broadens optical absorption but also significantly prolongs carrier lifetimes.This synergistic enhancement,coupled with the S-scheme charge transport mechanism,enables the composite to function as a bifunctional catalyst for photocat-alytic hydrogen production and simultaneous benzylamine coupling.The optimal system demonstrates an impressive hydrogen evolution rate of 8.5 mmol g^(-1) h^(-1) and an N-benzylidenebenzylamine yield of 4.6 mmol g^(-1) h^(-1) without requiring a cocatalyst.This work underscores the potential of integrating MOFs with LMCT states into S-scheme heterojunctions to enhance interfacial charge transfer,offering valuable insights for the design of S-scheme heterojunctions for artificial photosynthesis and related fields.展开更多
The electricity-driven water splitting acts as a promising pathway for renewable energy conversion and storage, yet anodic oxygen evolution reaction(OER) largely hinders its efficiency. Seeking the alternatives to OER...The electricity-driven water splitting acts as a promising pathway for renewable energy conversion and storage, yet anodic oxygen evolution reaction(OER) largely hinders its efficiency. Seeking the alternatives to OER exhibits the competitive advance to address this predicament. In this work, we show a more thermodynamically and kinetically favorable reaction, electrochemical oxidative dehydrogenation(EODH)of benzylamine to replace the conventional OER, catalyzed by a cobalt cyclotetraphosphate(Co_(2)P_(4)O_(12)) nanorods catalyst grown on nickel foam. This anodic reaction lowers the electricity input of 317 mV toward the desired current density of 100 mA/cm^(2), together with a highly selective benzonitrile product of more than 97%. More specifically, when coupling it with cathodic hydrogen evolution reaction(HER),the proposed HER||benzylamine-EODH configuration only requires a cell voltage of 1.47 V@100 mA/cm^(2),exhibiting an energy-saving up to 17% relative to conventional water splitting, as well as the near unit selectivity toward cathodic H_(2) and anodic benzonitrile products.展开更多
Donor-acceptor(D-A)conjugated polymers are widely used in photovoltaic applications and heteroge-neous catalysis due to their tunable building block and pre-designable structures.Here,a series of ad-justable Donor-acc...Donor-acceptor(D-A)conjugated polymers are widely used in photovoltaic applications and heteroge-neous catalysis due to their tunable building block and pre-designable structures.Here,a series of ad-justable Donor-acceptor(D-A)benzothiodiazole-based conjugated polymers were designed and synthe-sized.The photocatalytic performance could be improved by fine-tuning the chemical structure by halo-gen substitution(F or Cl).The polymers exhibited excellent optoelectronic properties and were effective photocatalysts for the degradation of RhB and MO dyes,as well as promoting the oxidative coupling of benzylamines.Complete degradation of RhB and MO occurred in 30 min under visible light radiation,while the yield of benzylamine coupling mediated by superoxide anion was as high as 82%.Systematic characterization methods were used to gain insights on the unique photocatalytic performance of the polymers.Our findings provide further insights into the design and synthesis of benzothiadiazole-based conjugated polymers as promising organic photocatalysts for solar energy conversion.展开更多
Benzylamine(BZA) has been identified as a promising candidate for CO_2 capture process; however the evaluation of BZA in the packed column was very few. Thus, in this work, the absorption and regeneration performance ...Benzylamine(BZA) has been identified as a promising candidate for CO_2 capture process; however the evaluation of BZA in the packed column was very few. Thus, in this work, the absorption and regeneration performance of unblended BZA solvent as well as a series of amine concentrations and ratios in the formulations were studied using a semibatch bubbling reactor. And due to the formation of ivory-white precipitates in solvents containing higher BZA ratios, a 4:1 molar ratio of MEA/BZA mixed solvent was used to study its performance in a pilot-scale test bed. The results showed that a higher BZA ratio in the MEA/BZA mixed solvent resulted in a faster absorption rate, a higher mass transfer and heat transfer rate and a better cyclic performance, but the mass transfer rate of BZA decreased more quickly than MEA with the increase of CO_2 loading of the solvents. In addition, at high CO_2 loading in the MEA/ BZA mixed solvent with a molar ratio of 4:1, the ivory-white precipitates were generated which could cause blockage of the packing in the absorber, the stripper and the liquid pipelines.展开更多
The employment of spin polarization under an external magnetic field holds great potential for the improvements of photocatalytic performance.However,owing to the huge difference in dielectric properties between ferro...The employment of spin polarization under an external magnetic field holds great potential for the improvements of photocatalytic performance.However,owing to the huge difference in dielectric properties between ferromagnetic oxide and polymers,the photogenerated excitons with spin states are often limited to the ferromagnetic oxide wells,which leads to unsatisfactory activity.In this paper,a single-atom Co-doped C_(3)N_(4)photocatalyst is successfully synthesized for photocatalytic water splitting and simultaneous oxidation of benzylamine.Under a tiny external magnetic field(24.5 mT),the hydrogen production rate could reach at 3979.0μmol·g^(-1)·h^(-1),which is about 340 times that of C_(3)N_(4).Experimental results and theoretical calculations indicate that the interaction of Co d and N p orbital changes the symmetry center of C_(3)N_(4),resulting in an increase in dielectric constant and spin polarization.Moreover,magnetic fields further promote parallel electron spin,and the increased number of charges with the parallel spin-down state is likely to dissociate under the action of an external magnetic field.On the other hand,the Co-N bond provides a huge built-in electric field and active site for strengthening the charge transfer and surface reaction.This work not only deepens the understanding of spin polarization,but also enriches methods to accelerate electron-hole separation.展开更多
The acid dissociation constants of N-carboxymethyl-N-(p-hydroxy phenyl carbamoyl- methyl)-2,3-dihydroxy-5-carbomethoxy benzylamine(CHDCB) and the stability constants of its 1:1 complexes with alkaline earth, Cd(Ⅱ), ...The acid dissociation constants of N-carboxymethyl-N-(p-hydroxy phenyl carbamoyl- methyl)-2,3-dihydroxy-5-carbomethoxy benzylamine(CHDCB) and the stability constants of its 1:1 complexes with alkaline earth, Cd(Ⅱ), Co(Ⅱ), Ni(Ⅱ), Cu(Ⅱ), Zn(Ⅱ), Fe(Ⅲ),Th(Ⅳ)and U(Ⅵ)ions have been determined at 25.0±0.1℃ and at an ionic strength of 0.1(KNO_3)by pH titration method. The probable coordination sites have also been discussed.展开更多
Alkylation of the ketimine 2 obtained from condensation of (+)-ketopinic acid and benzyla- mine with a variety of alkylating agents gives the products whose trends in diastereomeric excesses (1- 100% O. P.) appear to ...Alkylation of the ketimine 2 obtained from condensation of (+)-ketopinic acid and benzyla- mine with a variety of alkylating agents gives the products whose trends in diastereomeric excesses (1- 100% O. P.) appear to correlate with the structure and reactivity of electrophilic agents. Using excess n-butyl lithium and allylic or benzylic halides, β-alkylation occured.展开更多
The carbonyl addition of the pinanone ketimine derived from (+) or (-)-2-hydroxy-pinan- 3-one and benzylamine has been studied and the optically active α,β-substituted-β-aminoethanol deriva- tives were obtained in ...The carbonyl addition of the pinanone ketimine derived from (+) or (-)-2-hydroxy-pinan- 3-one and benzylamine has been studied and the optically active α,β-substituted-β-aminoethanol deriva- tives were obtained in good chemical yields (36.5-69.5%) with optical purity ranging from 1.4% to 99.9%.展开更多
The simultaneous accumulation of photo-holes and the specific activation of substrates present a significant challenge in photo-oxidation.Herein,we propose a dual-channel collaborative catalytic platform based on holl...The simultaneous accumulation of photo-holes and the specific activation of substrates present a significant challenge in photo-oxidation.Herein,we propose a dual-channel collaborative catalytic platform based on hollow TiO_(2) microspheres,using Cu single-atom(SA)catalysts and a composite polymer chain,to create separating pathways for unidirectional photogenerated electron/hole extraction.Ferrocene-functionalized graphene quantum dots are incorporated within the polymer chain for driving benzylamine(BA)oxidation.Quasi in situ transient photovoltage and femtosecond transient absorption tests reveal that leveraging the ultrafast charge separation capability of Cu SAs(0.44 ps)not only accelerates hole transport kinetics but also induces requisite Lewis acidity for the adsorption and activation of BA.In an air atmosphere,the rate of imine production reaches 4.81 mmol g^(−1) h^(−1)(selectivity of 98%).This study demonstrates the rational design of an SA/polymer chain dual-driven catalytic platform for optimizing kinetics and precisely controlling photocatalytic transformations in organic chemistry.展开更多
Selective oxidation of amines to imines through electrocatalysis is an attractive and efficient way for the chemical industry to produce nitrile compounds,but it is limited by the difficulty of designing efficient cat...Selective oxidation of amines to imines through electrocatalysis is an attractive and efficient way for the chemical industry to produce nitrile compounds,but it is limited by the difficulty of designing efficient catalysts and lack of understanding the mechanism of catalysis.Herein,we demonstrate a novel strategy by generation of oxyhydroxide layers on two-dimensional iron-doped layered nickel phosphorus trisulfides(Ni1-xFexPS_(3))during the oxidation of benzylamine(BA).In-depth structural and surface chemical characterizations during the electrocatalytic process combined with theoretical calculations reveal that Ni(1-x)FexPS_(3) undergoes surface reconstruction under alkaline conditions to form the metal oxyhydroxide/phosphorus trichalcogenide(NiFeOOH/Ni1-xFexPS_(3))heterostructure.Interestingly,the generated heterointerface facilitates BA oxidation with a low onset potential of 1.39 V and Faradaic efficiency of 53%for benzonitrile(BN)synthesis.Theoretical calculations further indicate that the as-formed NiFeOOH/Ni1-xFexPS_(3) heterostructure could offer optimum free energy for BA adsorption and BN desorption,resulting in promising BN synthesis.展开更多
Non-metallic nanocarbon materials catalyzed coupling reactions of primary amines to produce imine is an efficient,green and sustainable synthetic route,which has a wide application prospect in fine chemicals or pharma...Non-metallic nanocarbon materials catalyzed coupling reactions of primary amines to produce imine is an efficient,green and sustainable synthetic route,which has a wide application prospect in fine chemicals or pharmaceutical molecules.In the present study,we show firstly the relatively high catalytic activity of graphene oxide in the reaction of oxidative coupling of benzylamine(OCB),which is even comparable with typical metal-based catalysts,indicating the great potential of nanocarbon materials in this reaction system.More importantly,a novel twophoton fluorescence probe molecule(N-propyl-4-hydrazinyl-1,8-naphthalimide,NA)with special chemical structure of hydrazine functionality was synthesized.The probe NA could selectively react with aldehyde or ketone compounds,leading to the photoluminescence enhancement via inhibition of photo induced electron transfer(PET)process.The synthesized NA was applied as probe in carbon catalyzed OCB system to predict the existence of reaction intermediate benzaldehyde(BA),indicating the reaction pathway of oxidation-deamination-condensation in nanocarbon catalyzed OCB process.The proposed luminescence-probe strategy for revealing the kinetics and mechanism may also shed light in other reaction systems concerning the intermediates or products of ketones or aldehydes.展开更多
Regulation of the Li_(2)CO_(3) byproduct is the most critical challenge in the field of non-aqueous Li–O_(2) batteries.Although considerable efforts have been devoted to preventing Li_(2)CO_(3) formation,no approache...Regulation of the Li_(2)CO_(3) byproduct is the most critical challenge in the field of non-aqueous Li–O_(2) batteries.Although considerable efforts have been devoted to preventing Li_(2)CO_(3) formation,no approaches have suggested the ultimate solution of utilizing the clean Li_(2)O_(2) reaction instead of that of Li_(2)CO_(3).Even if extremely pure O_(2) is used in a Li–O_(2) cell,its complete elimination is impossible,eventually generating CO_(2) gas during charge.In this paper,we present the new concept of a CO_(2)-adsorbent spongy electrode(CASE),which is designed to trap the evolved CO_(2) using adsorption materials.Various candidates composed of amine functional groups(–NH2)for capturing CO_(2) were screened,with quadrapurebenzylamine(QPBZA)exhibiting superior CO_(2)-adsorbing ability among the proposed candidates.Accordingly,we fabricated the CASE by sandwiching QPBZA between porous carbon layers,which facilitated the transport of gaseous products.The new electrode was demonstrated to effectively capture the evolved CO_(2) during charge,therefore altering the reaction pathways to the ideal case.It is highly advantageous to mitigate the undesirable CO_(2) incorporation in the next discharge,resulting in improved cyclability.This novel concept of a CO_(2)-sponging electrode provides an alternative route to the realization of practically meaningful Li–O_(2) batteries.展开更多
The title compound was prepared from the mixture of cobalt ( Ⅱ ) acetate, chromium trioxide and pyridine in an aqueous solution, and its structure was determined by X-ray single crystal diffraction method. A number o...The title compound was prepared from the mixture of cobalt ( Ⅱ ) acetate, chromium trioxide and pyridine in an aqueous solution, and its structure was determined by X-ray single crystal diffraction method. A number of alcohols, benzyl halides and benzy-lamines can be oxidized by this oxidant to the corresponding aldehydes in high yields.展开更多
Primary tosylates 1a-d were converted to the corresponding amino species 3a-d. Benzylamine was proved effective for the substitution of tosylates, using acetonitrile (MeCN) as the solvent of choice and citric acid to ...Primary tosylates 1a-d were converted to the corresponding amino species 3a-d. Benzylamine was proved effective for the substitution of tosylates, using acetonitrile (MeCN) as the solvent of choice and citric acid to remove excess of the reagent from crude products 2a-d. Debenzylation was carried out at circa (ca.) atmospheric pressure of hydrogen gas in the presence of acetic acid (AcOH). The method was also demonstrated in a demo batch experiment for the synthesis of compound 3a on a 50 g scale of 1a.展开更多
Photocatalytic water splitting is a popular pathway for H_(2)evolution,but the slow water oxidation greatly hampers the overall activity.To harness photogenerated holes in an efficient and lucrative way,the wa-ter oxi...Photocatalytic water splitting is a popular pathway for H_(2)evolution,but the slow water oxidation greatly hampers the overall activity.To harness photogenerated holes in an efficient and lucrative way,the wa-ter oxidation reaction is replaced by selective oxidation of organic compounds to achieve simultaneous production of H_(2)and value-added chemicals.Herein,an alternative tactic is reported where an organic compound(benzylamine,BA)not only serves as the precursor for N-benzylidene-benzylamine(NBBA)production but also provides hydrogen sources for H_(2)evolution,achieving the goal under anhydrous conditions.This process is realized using an S-scheme photocatalyst composed of ZnIn_(2)S_(4)and the UiO-66-NH_(2)(U6N)metal-organic framework(MOF).The S-scheme carrier transfer mechanism was validated by in-situ irradiated X-ray photoelectron spectroscopy(ISI-XPS)and femtosecond transient absorption(fs-TA)spectroscopy.With increased carrier efficiency and reinforced redox power endowed by the S-scheme heterojunction,the composite performed better than ZnIn2 S4 and MOF.The performance was further ameliorated by Pt-cocatalyst modification,achieving an H_(2)production rate of 5275μmol h^(-1)g^(-1)as well as BA conversion of 94.3%with 99.3%NBBA selectivity.Mechanistic studies reveal that BA is ini-tially oxidized to carbon-centered radicals and further to imines along with the release of protons.The imine reacts with another BA molecule to form NBBA,while the protons are reduced to H_(2).This work provides new insights into concurrent photocatalytic H_(2)production and selective organic oxidation from organic amines using S-scheme photocatalysts.展开更多
Covalent organic frameworks(COFs)constitute a novel category of porous materials that exhibit considerable promise for photocatalysis,particularly in the production of hydrogen peroxide(H_(2)O_(2)).A novel COF disting...Covalent organic frameworks(COFs)constitute a novel category of porous materials that exhibit considerable promise for photocatalysis,particularly in the production of hydrogen peroxide(H_(2)O_(2)).A novel COF distinguished by a pyrene-anthraquinone architecture(denoted as Py-DQ-COF)was successfully prepared through a solvothermal process.The pyrene moiety acts as an electron-rich component,while the anthraquinone moiety serves as its electron-deficient counterpart.The strategic integration of these two moieties as essential building blocks in the formation of a donor-acceptor type Py-DQ-COF structure facilitates the efficient separation of electron-hole pairs.By employing benzylamine as a sacrificial reagent and utilizing water as the solvent,this study meticulously explores the photocatalytic efficiency in the production of H_(2)O_(2).Mechanistic investigations validate that the reaction proceeds through a two-step two-electron(2e-)oxygen reduction reaction pathway,culminating in an impressive H_(2)O_(2)yield of 15,207µmol g^(-1)h^(-1),significantly exceeding the yields associated with conventional sacrificial alcohols.Cyclic experiments further elucidate that the materials exhibit commendable stability and sustain high activity.This study introduces a new method for the identification of novel sacrificial agents,and integrates anthraquinone into COFs,thereby offering an efficient strategy to optimize the industrial anthraquinone process for H_(2)O_(2)production.Ultimately,it provides a valuable reference for the advancement of efficient and sustainable photocatalytic systems.展开更多
Replacing the challenging water oxidation with thermodynamically favorable organic oxidation presents a promising strategy for the efficient simultaneous production of hydrogen and value-added chemicals.However,photoc...Replacing the challenging water oxidation with thermodynamically favorable organic oxidation presents a promising strategy for the efficient simultaneous production of hydrogen and value-added chemicals.However,photocatalytic activity is hindered by inefficient separation of photogenerated electron-hole pairs and limited redox active sites.Herein,Fe/ZnIn_(2)S_(4)/Ni(Fe/ZIS/Ni)micro heterojunctions were rationally engineered for synergistically photocatalytic hydrogen evolution and selective oxidation of benzylamine.Using Fe-based metal-organic frameworks(MIL-88A)as the self-etching morphology template and iron source,ZIS was grown in situ to obtain Fe-doped ZIS(Fe/ZIS).Then nickel was introduced into Fe/ZIS to locally construct Ni-doped ZIS(ZIS/Ni)microregion,thereby forming numerous microscopic heterojunctions(Fe/ZIS/Ni).The introduction of Fe effectively lowers the energy band(EB)position of Fe/ZIS,while the introduction of Ni elevates the EB position of ZIS/Ni microregion.Such difference in the EB structures of Fe/ZIS and ZIS/Ni promote the formation of local electric field,effectively suppresses the recombination of photogenerated carriers and enhances their efficient separation and migration.Moreover,the nanosheet assembly structure increases the availability of active sites and enhances the uptake of reactants.The optimized Fe/ZIS/Ni catalyst achieves remarkable hydrogen evolution and N-benzylidenebenzylamine(NBI)production rates of 7.9 and 6.8 mmol·g^(-1)·h^(-1),respectively.Additionally,the selectivity for the oxidation of benzylamine to NBI exceeds 95%.This work establishes a novel design paradigm for developing high-performance photocatalytic systems that integrate renewable H2 production with selective organic transformations.展开更多
Photocatalytic oxidation of organic molecules into highly value-added products is an innovative and challenging research which has gradually attracted remarkable attention of scientists.In this work,it is demonstrated...Photocatalytic oxidation of organic molecules into highly value-added products is an innovative and challenging research which has gradually attracted remarkable attention of scientists.In this work,it is demonstrated that the COF-TpPa with keto-enol tautomerism equilibrium structure shows excellent performance(yield>99%after 8 h)in the selective photocatalytic oxidative coupling of amines to imines under visible light irradiation.It is revealed that three kinds of reactive oxygen species(superoxide radical,hydroxyl radical and singlet oxygen)participate in this photocatalytic oxidation reaction.In addition,hydrogen protons cleaved from the benzyl are proven to be reduced to hydrogen in the conduction band of COF-TpPa in anaerobic atmosphere,accompanied with the formation of imines.The direct hydrogen evolution from amine provides an effective way to extract clean energy from organic molecule as well as the production of value-added chemicals.As a contrast,COF-LZU1 with similar structure and chemical composition to COF-TpPa but without keto-enol tautomerism exhibits worse optical properties and photocatalytic performance.It is also demonstrated that keto-enol tautomerism favors the adsorption of benzylamine based on the characterization results and theoretical calculations.展开更多
A series of nickel-doped copper tungstate/oxygen-rich TiO_(2) heterojunction-constructed composites of xNi-CuWO_(4)/OTiO_(2) were successfully prepared to demonstrate the enhancement of the visible-light photoactivity...A series of nickel-doped copper tungstate/oxygen-rich TiO_(2) heterojunction-constructed composites of xNi-CuWO_(4)/OTiO_(2) were successfully prepared to demonstrate the enhancement of the visible-light photoactivity through promoting the photogenerated charge carrier separation efficiency.Of all these composites,0.2Ni-CuWO_(4)/OTiO_(2) exhibits excellent and stable visible light photoactivity for the photooxidative coupling of benzylamine to the corresponding N-benzyl-1-phenymethanimine(BPMI)in air atmosphere.The conversion of benzylamine and the selectivity to BPMI reach 97%and 99%,respectively.The catalyst shows good cyclability with the conversion of benzylamine decreasing just by 22%after being repeated six times with the well-maintained selectivity of BPMI.The composite also exhibits excellent photo-bactericidal ability,which greatly inhibits the reproducing of both the Gram-positive bacteria(e.g.,S.epidermidis)and Gram-negative bacteria(e.g.,E.coli).展开更多
Photocatalytic hydrogen evolution coupled with organic oxidation holds great promise for converting solar energy into high-valueadded chemicals,but it is hampered by sluggish charge dynamics and limited redox potentia...Photocatalytic hydrogen evolution coupled with organic oxidation holds great promise for converting solar energy into high-valueadded chemicals,but it is hampered by sluggish charge dynamics and limited redox potential.Herein,a porous S-doped carbon nitride(S-C_(3)N_(4−y))foam assembled from ultrathin nanosheets with rich nitrogen vacancies was synthesized using a molecular selfassembly strategy.The S dopants and N vacancies synergistically adjusted the band structure,facilitating light absorption and enhancing the oxidation ability.Moreover,the ultrathin nanosheets and porous structure provided more exposed active sites and facilitated mass and charge transfer.Consequently,S-C_(3)N_(4−y)foam exhibited enhanced photocatalytic activities for synchronous hydrogen evolution(4960μmol/(h·g))and benzylamine oxidation to N-benzylidenebenzylamine(4885μmol/(h·g))with high selectivity of>99%,which were approximately 17.6 and 72.9 times higher than those of bulk CN,respectively.The photocatalytic coupling pairing reaction promotes the water splitting by consuming H2O2,thereby improving the hydrogen evolution efficiency and achieving the production of high value-added imines.This study provides an effective route for regulating the morphology and band structure of carbon nitride for synthesizing highly valuable chemicals.展开更多
基金financially supported by the National Key Re-search and Development Program of China(Nos.2022YFB3803600 and 2022YFE0115900)the National Natural Science Foundation of China(Nos.U24A2071,22278324,22238009,22361142704,22202187,and U23A20102)+1 种基金the National Science Foundation of Hubei Province of China(No.2022CFA001)Key R&D Program Projects in Hubei Province(No.2023BAB113).
文摘S-scheme heterojunctions have gained widespread application in photocatalytic reactions due to their dis-tinctive carrier transport mechanism and remarkable redox capabilities.However,a significant challenge persists in extending carrier lifetimes while simultaneously enhancing light absorption,both of which are essential for optimizing photocatalytic activity.Herein,we report the solvothermal synthesis of ul-trathin CdS nanosheets grown in situ on two-dimensional(2D)Ni-MOF to construct 2D/2D S-scheme heterojunctions.Comprehensive characterizations reveal that the incorporation of Ni-MOF(metal-organic framework)with ligand-to-metal charge transfer(LMCT)states not only broadens optical absorption but also significantly prolongs carrier lifetimes.This synergistic enhancement,coupled with the S-scheme charge transport mechanism,enables the composite to function as a bifunctional catalyst for photocat-alytic hydrogen production and simultaneous benzylamine coupling.The optimal system demonstrates an impressive hydrogen evolution rate of 8.5 mmol g^(-1) h^(-1) and an N-benzylidenebenzylamine yield of 4.6 mmol g^(-1) h^(-1) without requiring a cocatalyst.This work underscores the potential of integrating MOFs with LMCT states into S-scheme heterojunctions to enhance interfacial charge transfer,offering valuable insights for the design of S-scheme heterojunctions for artificial photosynthesis and related fields.
基金financially supported in part by National Key R&D Program of China(No.2020YFA0406103)National Natural Science Foundation of China(NSFC,Nos.21725102,22122506,22075267,U1832156,91961106,51902311)+5 种基金DNL Cooperation Fund,CAS(No.DNL201922)Strategic Priority Research Program of the CAS(No.XDPB14)Anhui Provincial Natural Science Foundation(No.2008085J05)Youth Innovation Promotion Association of CAS(No.2019444)Open Funding Project of National Key Laboratory of Human Factors Engineering(No.SYFD062010K)support from USTC Center for Micro-and Nanoscale Research and Fabrication。
文摘The electricity-driven water splitting acts as a promising pathway for renewable energy conversion and storage, yet anodic oxygen evolution reaction(OER) largely hinders its efficiency. Seeking the alternatives to OER exhibits the competitive advance to address this predicament. In this work, we show a more thermodynamically and kinetically favorable reaction, electrochemical oxidative dehydrogenation(EODH)of benzylamine to replace the conventional OER, catalyzed by a cobalt cyclotetraphosphate(Co_(2)P_(4)O_(12)) nanorods catalyst grown on nickel foam. This anodic reaction lowers the electricity input of 317 mV toward the desired current density of 100 mA/cm^(2), together with a highly selective benzonitrile product of more than 97%. More specifically, when coupling it with cathodic hydrogen evolution reaction(HER),the proposed HER||benzylamine-EODH configuration only requires a cell voltage of 1.47 V@100 mA/cm^(2),exhibiting an energy-saving up to 17% relative to conventional water splitting, as well as the near unit selectivity toward cathodic H_(2) and anodic benzonitrile products.
基金financially supported by National Natural Science Foundation of China(No.52173099)the Science and Technology Department of Jiangxi Province(No.20192BBEL50025)+1 种基金Nanchang Hangkong University(No.EA201902288)the Special Fund for Graduate Innovation(No.YC2020-011).
文摘Donor-acceptor(D-A)conjugated polymers are widely used in photovoltaic applications and heteroge-neous catalysis due to their tunable building block and pre-designable structures.Here,a series of ad-justable Donor-acceptor(D-A)benzothiodiazole-based conjugated polymers were designed and synthe-sized.The photocatalytic performance could be improved by fine-tuning the chemical structure by halo-gen substitution(F or Cl).The polymers exhibited excellent optoelectronic properties and were effective photocatalysts for the degradation of RhB and MO dyes,as well as promoting the oxidative coupling of benzylamines.Complete degradation of RhB and MO occurred in 30 min under visible light radiation,while the yield of benzylamine coupling mediated by superoxide anion was as high as 82%.Systematic characterization methods were used to gain insights on the unique photocatalytic performance of the polymers.Our findings provide further insights into the design and synthesis of benzothiadiazole-based conjugated polymers as promising organic photocatalysts for solar energy conversion.
基金supported by the Sinopec Ningbo Engineering Co. Ltd. (No.l4850000-14-ZC0609-0003,H8XY-0032)
文摘Benzylamine(BZA) has been identified as a promising candidate for CO_2 capture process; however the evaluation of BZA in the packed column was very few. Thus, in this work, the absorption and regeneration performance of unblended BZA solvent as well as a series of amine concentrations and ratios in the formulations were studied using a semibatch bubbling reactor. And due to the formation of ivory-white precipitates in solvents containing higher BZA ratios, a 4:1 molar ratio of MEA/BZA mixed solvent was used to study its performance in a pilot-scale test bed. The results showed that a higher BZA ratio in the MEA/BZA mixed solvent resulted in a faster absorption rate, a higher mass transfer and heat transfer rate and a better cyclic performance, but the mass transfer rate of BZA decreased more quickly than MEA with the increase of CO_2 loading of the solvents. In addition, at high CO_2 loading in the MEA/ BZA mixed solvent with a molar ratio of 4:1, the ivory-white precipitates were generated which could cause blockage of the packing in the absorber, the stripper and the liquid pipelines.
基金This project was financially supported by the Guizhou Provincial Science and Technology Foundation(No.ZK2021069)the National Natural Science Foundation of China(No.22268015)+1 种基金the Young Science and Technology Talents Development Project of Education Department in Guizhou Province(No.KY2022144)the Innovation Group Project of Education Department in Guizhou Province(NO.2021010).
文摘The employment of spin polarization under an external magnetic field holds great potential for the improvements of photocatalytic performance.However,owing to the huge difference in dielectric properties between ferromagnetic oxide and polymers,the photogenerated excitons with spin states are often limited to the ferromagnetic oxide wells,which leads to unsatisfactory activity.In this paper,a single-atom Co-doped C_(3)N_(4)photocatalyst is successfully synthesized for photocatalytic water splitting and simultaneous oxidation of benzylamine.Under a tiny external magnetic field(24.5 mT),the hydrogen production rate could reach at 3979.0μmol·g^(-1)·h^(-1),which is about 340 times that of C_(3)N_(4).Experimental results and theoretical calculations indicate that the interaction of Co d and N p orbital changes the symmetry center of C_(3)N_(4),resulting in an increase in dielectric constant and spin polarization.Moreover,magnetic fields further promote parallel electron spin,and the increased number of charges with the parallel spin-down state is likely to dissociate under the action of an external magnetic field.On the other hand,the Co-N bond provides a huge built-in electric field and active site for strengthening the charge transfer and surface reaction.This work not only deepens the understanding of spin polarization,but also enriches methods to accelerate electron-hole separation.
文摘The acid dissociation constants of N-carboxymethyl-N-(p-hydroxy phenyl carbamoyl- methyl)-2,3-dihydroxy-5-carbomethoxy benzylamine(CHDCB) and the stability constants of its 1:1 complexes with alkaline earth, Cd(Ⅱ), Co(Ⅱ), Ni(Ⅱ), Cu(Ⅱ), Zn(Ⅱ), Fe(Ⅲ),Th(Ⅳ)and U(Ⅵ)ions have been determined at 25.0±0.1℃ and at an ionic strength of 0.1(KNO_3)by pH titration method. The probable coordination sites have also been discussed.
基金The subject was supported by the National Natural Science Foundation of China
文摘Alkylation of the ketimine 2 obtained from condensation of (+)-ketopinic acid and benzyla- mine with a variety of alkylating agents gives the products whose trends in diastereomeric excesses (1- 100% O. P.) appear to correlate with the structure and reactivity of electrophilic agents. Using excess n-butyl lithium and allylic or benzylic halides, β-alkylation occured.
基金This project is supported by the National Natural Science Foundation of China
文摘The carbonyl addition of the pinanone ketimine derived from (+) or (-)-2-hydroxy-pinan- 3-one and benzylamine has been studied and the optically active α,β-substituted-β-aminoethanol deriva- tives were obtained in good chemical yields (36.5-69.5%) with optical purity ranging from 1.4% to 99.9%.
基金financial support provided by the National Natural Science Foundation of China(No.22172057).
文摘The simultaneous accumulation of photo-holes and the specific activation of substrates present a significant challenge in photo-oxidation.Herein,we propose a dual-channel collaborative catalytic platform based on hollow TiO_(2) microspheres,using Cu single-atom(SA)catalysts and a composite polymer chain,to create separating pathways for unidirectional photogenerated electron/hole extraction.Ferrocene-functionalized graphene quantum dots are incorporated within the polymer chain for driving benzylamine(BA)oxidation.Quasi in situ transient photovoltage and femtosecond transient absorption tests reveal that leveraging the ultrafast charge separation capability of Cu SAs(0.44 ps)not only accelerates hole transport kinetics but also induces requisite Lewis acidity for the adsorption and activation of BA.In an air atmosphere,the rate of imine production reaches 4.81 mmol g^(−1) h^(−1)(selectivity of 98%).This study demonstrates the rational design of an SA/polymer chain dual-driven catalytic platform for optimizing kinetics and precisely controlling photocatalytic transformations in organic chemistry.
基金National Natural Science Foundation of China,Grant/Award Number:22179029Fundamental Research Funds for the Central Universities,Grant/Award Number:buctrc202324+2 种基金Young Elite Scientists Sponsorship Program by BAST,Grant/Award Number:BYESS2023093Ministero dell'Istruzione,dell'Universitàe della Ricerca,Grant/Award Number:2022FNL89YKempestiftelserna。
文摘Selective oxidation of amines to imines through electrocatalysis is an attractive and efficient way for the chemical industry to produce nitrile compounds,but it is limited by the difficulty of designing efficient catalysts and lack of understanding the mechanism of catalysis.Herein,we demonstrate a novel strategy by generation of oxyhydroxide layers on two-dimensional iron-doped layered nickel phosphorus trisulfides(Ni1-xFexPS_(3))during the oxidation of benzylamine(BA).In-depth structural and surface chemical characterizations during the electrocatalytic process combined with theoretical calculations reveal that Ni(1-x)FexPS_(3) undergoes surface reconstruction under alkaline conditions to form the metal oxyhydroxide/phosphorus trichalcogenide(NiFeOOH/Ni1-xFexPS_(3))heterostructure.Interestingly,the generated heterointerface facilitates BA oxidation with a low onset potential of 1.39 V and Faradaic efficiency of 53%for benzonitrile(BN)synthesis.Theoretical calculations further indicate that the as-formed NiFeOOH/Ni1-xFexPS_(3) heterostructure could offer optimum free energy for BA adsorption and BN desorption,resulting in promising BN synthesis.
基金financial support from the NSFC of China(22072163,21761132010,and 91645114)the Youth Innovation Promotion Association,CAS,China,Natural Science Foundation of Liaoning Province of China(2020-YQ-02).
文摘Non-metallic nanocarbon materials catalyzed coupling reactions of primary amines to produce imine is an efficient,green and sustainable synthetic route,which has a wide application prospect in fine chemicals or pharmaceutical molecules.In the present study,we show firstly the relatively high catalytic activity of graphene oxide in the reaction of oxidative coupling of benzylamine(OCB),which is even comparable with typical metal-based catalysts,indicating the great potential of nanocarbon materials in this reaction system.More importantly,a novel twophoton fluorescence probe molecule(N-propyl-4-hydrazinyl-1,8-naphthalimide,NA)with special chemical structure of hydrazine functionality was synthesized.The probe NA could selectively react with aldehyde or ketone compounds,leading to the photoluminescence enhancement via inhibition of photo induced electron transfer(PET)process.The synthesized NA was applied as probe in carbon catalyzed OCB system to predict the existence of reaction intermediate benzaldehyde(BA),indicating the reaction pathway of oxidation-deamination-condensation in nanocarbon catalyzed OCB process.The proposed luminescence-probe strategy for revealing the kinetics and mechanism may also shed light in other reaction systems concerning the intermediates or products of ketones or aldehydes.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT)(No.2021R1C1C1003628)the Development Program of Core Industrial Technology,funded by the Ministry of Trade,Industry&Energy of Korea(20012318)the institutional program of the Korea Institute of Science and Technology(2E31001)。
文摘Regulation of the Li_(2)CO_(3) byproduct is the most critical challenge in the field of non-aqueous Li–O_(2) batteries.Although considerable efforts have been devoted to preventing Li_(2)CO_(3) formation,no approaches have suggested the ultimate solution of utilizing the clean Li_(2)O_(2) reaction instead of that of Li_(2)CO_(3).Even if extremely pure O_(2) is used in a Li–O_(2) cell,its complete elimination is impossible,eventually generating CO_(2) gas during charge.In this paper,we present the new concept of a CO_(2)-adsorbent spongy electrode(CASE),which is designed to trap the evolved CO_(2) using adsorption materials.Various candidates composed of amine functional groups(–NH2)for capturing CO_(2) were screened,with quadrapurebenzylamine(QPBZA)exhibiting superior CO_(2)-adsorbing ability among the proposed candidates.Accordingly,we fabricated the CASE by sandwiching QPBZA between porous carbon layers,which facilitated the transport of gaseous products.The new electrode was demonstrated to effectively capture the evolved CO_(2) during charge,therefore altering the reaction pathways to the ideal case.It is highly advantageous to mitigate the undesirable CO_(2) incorporation in the next discharge,resulting in improved cyclability.This novel concept of a CO_(2)-sponging electrode provides an alternative route to the realization of practically meaningful Li–O_(2) batteries.
文摘The title compound was prepared from the mixture of cobalt ( Ⅱ ) acetate, chromium trioxide and pyridine in an aqueous solution, and its structure was determined by X-ray single crystal diffraction method. A number of alcohols, benzyl halides and benzy-lamines can be oxidized by this oxidant to the corresponding aldehydes in high yields.
文摘Primary tosylates 1a-d were converted to the corresponding amino species 3a-d. Benzylamine was proved effective for the substitution of tosylates, using acetonitrile (MeCN) as the solvent of choice and citric acid to remove excess of the reagent from crude products 2a-d. Debenzylation was carried out at circa (ca.) atmospheric pressure of hydrogen gas in the presence of acetic acid (AcOH). The method was also demonstrated in a demo batch experiment for the synthesis of compound 3a on a 50 g scale of 1a.
基金supported by the National Key Research and Development Program of China(Nos.2022YFB3803600 and 2022YFE0115900)the National Natural Science Foundation of China(Nos.22208332,22278324,52073223,22238009,51932007,22361142704)+1 种基金the Natural Science Foundation of Hubei Province of China(No.2022CFA001)the Key R&D Program Projects in Hubei Province(No.2023BAB113).
文摘Photocatalytic water splitting is a popular pathway for H_(2)evolution,but the slow water oxidation greatly hampers the overall activity.To harness photogenerated holes in an efficient and lucrative way,the wa-ter oxidation reaction is replaced by selective oxidation of organic compounds to achieve simultaneous production of H_(2)and value-added chemicals.Herein,an alternative tactic is reported where an organic compound(benzylamine,BA)not only serves as the precursor for N-benzylidene-benzylamine(NBBA)production but also provides hydrogen sources for H_(2)evolution,achieving the goal under anhydrous conditions.This process is realized using an S-scheme photocatalyst composed of ZnIn_(2)S_(4)and the UiO-66-NH_(2)(U6N)metal-organic framework(MOF).The S-scheme carrier transfer mechanism was validated by in-situ irradiated X-ray photoelectron spectroscopy(ISI-XPS)and femtosecond transient absorption(fs-TA)spectroscopy.With increased carrier efficiency and reinforced redox power endowed by the S-scheme heterojunction,the composite performed better than ZnIn2 S4 and MOF.The performance was further ameliorated by Pt-cocatalyst modification,achieving an H_(2)production rate of 5275μmol h^(-1)g^(-1)as well as BA conversion of 94.3%with 99.3%NBBA selectivity.Mechanistic studies reveal that BA is ini-tially oxidized to carbon-centered radicals and further to imines along with the release of protons.The imine reacts with another BA molecule to form NBBA,while the protons are reduced to H_(2).This work provides new insights into concurrent photocatalytic H_(2)production and selective organic oxidation from organic amines using S-scheme photocatalysts.
基金supported by the National Key Research and Development Program of China(2021YFA1501500,2018YFA0208604)the National Natural Science Foundation of China(22033008,22220102005,22171265)+1 种基金the Fujian Science&Technology Innovation Laboratory for Optoelectronic Information of China(2021ZZ103)the Natural Science Foundation of Fujian Province(2023J05087)。
文摘Covalent organic frameworks(COFs)constitute a novel category of porous materials that exhibit considerable promise for photocatalysis,particularly in the production of hydrogen peroxide(H_(2)O_(2)).A novel COF distinguished by a pyrene-anthraquinone architecture(denoted as Py-DQ-COF)was successfully prepared through a solvothermal process.The pyrene moiety acts as an electron-rich component,while the anthraquinone moiety serves as its electron-deficient counterpart.The strategic integration of these two moieties as essential building blocks in the formation of a donor-acceptor type Py-DQ-COF structure facilitates the efficient separation of electron-hole pairs.By employing benzylamine as a sacrificial reagent and utilizing water as the solvent,this study meticulously explores the photocatalytic efficiency in the production of H_(2)O_(2).Mechanistic investigations validate that the reaction proceeds through a two-step two-electron(2e-)oxygen reduction reaction pathway,culminating in an impressive H_(2)O_(2)yield of 15,207µmol g^(-1)h^(-1),significantly exceeding the yields associated with conventional sacrificial alcohols.Cyclic experiments further elucidate that the materials exhibit commendable stability and sustain high activity.This study introduces a new method for the identification of novel sacrificial agents,and integrates anthraquinone into COFs,thereby offering an efficient strategy to optimize the industrial anthraquinone process for H_(2)O_(2)production.Ultimately,it provides a valuable reference for the advancement of efficient and sustainable photocatalytic systems.
基金supported by the National Key R&D Program of China(No.2022YFA1503003)the National Natural Science Foundation of China(No.22271081)+2 种基金the Postdoctoral Science Foundation of Heilongjiang Province(No.LBH-Z22240)the Basic Research Fund of Heilongjiang University in Heilongjiang Province(No.2022-KYYWF-1060)the Heilongjiang University Excellent Youth Foundation.
文摘Replacing the challenging water oxidation with thermodynamically favorable organic oxidation presents a promising strategy for the efficient simultaneous production of hydrogen and value-added chemicals.However,photocatalytic activity is hindered by inefficient separation of photogenerated electron-hole pairs and limited redox active sites.Herein,Fe/ZnIn_(2)S_(4)/Ni(Fe/ZIS/Ni)micro heterojunctions were rationally engineered for synergistically photocatalytic hydrogen evolution and selective oxidation of benzylamine.Using Fe-based metal-organic frameworks(MIL-88A)as the self-etching morphology template and iron source,ZIS was grown in situ to obtain Fe-doped ZIS(Fe/ZIS).Then nickel was introduced into Fe/ZIS to locally construct Ni-doped ZIS(ZIS/Ni)microregion,thereby forming numerous microscopic heterojunctions(Fe/ZIS/Ni).The introduction of Fe effectively lowers the energy band(EB)position of Fe/ZIS,while the introduction of Ni elevates the EB position of ZIS/Ni microregion.Such difference in the EB structures of Fe/ZIS and ZIS/Ni promote the formation of local electric field,effectively suppresses the recombination of photogenerated carriers and enhances their efficient separation and migration.Moreover,the nanosheet assembly structure increases the availability of active sites and enhances the uptake of reactants.The optimized Fe/ZIS/Ni catalyst achieves remarkable hydrogen evolution and N-benzylidenebenzylamine(NBI)production rates of 7.9 and 6.8 mmol·g^(-1)·h^(-1),respectively.Additionally,the selectivity for the oxidation of benzylamine to NBI exceeds 95%.This work establishes a novel design paradigm for developing high-performance photocatalytic systems that integrate renewable H2 production with selective organic transformations.
基金supported by the National Natural Science Foundation of China (51802015, 51972024)the Fundamental Research Funds for the Central Universities (FRF-TP-20-005A3)the Interdisciplinary Research Project for Young Teachers of USTB (Fundamental Research Funds for the Central Universities) (FRF-IDRY-19-020)。
文摘Photocatalytic oxidation of organic molecules into highly value-added products is an innovative and challenging research which has gradually attracted remarkable attention of scientists.In this work,it is demonstrated that the COF-TpPa with keto-enol tautomerism equilibrium structure shows excellent performance(yield>99%after 8 h)in the selective photocatalytic oxidative coupling of amines to imines under visible light irradiation.It is revealed that three kinds of reactive oxygen species(superoxide radical,hydroxyl radical and singlet oxygen)participate in this photocatalytic oxidation reaction.In addition,hydrogen protons cleaved from the benzyl are proven to be reduced to hydrogen in the conduction band of COF-TpPa in anaerobic atmosphere,accompanied with the formation of imines.The direct hydrogen evolution from amine provides an effective way to extract clean energy from organic molecule as well as the production of value-added chemicals.As a contrast,COF-LZU1 with similar structure and chemical composition to COF-TpPa but without keto-enol tautomerism exhibits worse optical properties and photocatalytic performance.It is also demonstrated that keto-enol tautomerism favors the adsorption of benzylamine based on the characterization results and theoretical calculations.
基金financially supported by NSFC(52063026,21563026)the Program for Changjiang Scholars and Innovative Research Team in University(IRT15R56)+2 种基金the Innovation Team Basic Scientific Research Project of Gansu Province(1606RJIA324)the Science,Technology Program of GansuProvince(19JR2RA020)Education Department of Gansu Province:Excellent Graduate Student"lnnovation Star"Project(2021CXZX001).
文摘A series of nickel-doped copper tungstate/oxygen-rich TiO_(2) heterojunction-constructed composites of xNi-CuWO_(4)/OTiO_(2) were successfully prepared to demonstrate the enhancement of the visible-light photoactivity through promoting the photogenerated charge carrier separation efficiency.Of all these composites,0.2Ni-CuWO_(4)/OTiO_(2) exhibits excellent and stable visible light photoactivity for the photooxidative coupling of benzylamine to the corresponding N-benzyl-1-phenymethanimine(BPMI)in air atmosphere.The conversion of benzylamine and the selectivity to BPMI reach 97%and 99%,respectively.The catalyst shows good cyclability with the conversion of benzylamine decreasing just by 22%after being repeated six times with the well-maintained selectivity of BPMI.The composite also exhibits excellent photo-bactericidal ability,which greatly inhibits the reproducing of both the Gram-positive bacteria(e.g.,S.epidermidis)and Gram-negative bacteria(e.g.,E.coli).
基金the National Key Research and Development Program of China(No.2022YFA1503003)the National Natural Science Foundation of China(Nos.U20A20250 and 22271081)+1 种基金the Natural Science Foundation of Heilongjiang Province(No.ZD2021B003)the University Nursing Program for Young Scholars with Creative Talents in Heilongjiang Province(No.UNPYSCT-2020004).
文摘Photocatalytic hydrogen evolution coupled with organic oxidation holds great promise for converting solar energy into high-valueadded chemicals,but it is hampered by sluggish charge dynamics and limited redox potential.Herein,a porous S-doped carbon nitride(S-C_(3)N_(4−y))foam assembled from ultrathin nanosheets with rich nitrogen vacancies was synthesized using a molecular selfassembly strategy.The S dopants and N vacancies synergistically adjusted the band structure,facilitating light absorption and enhancing the oxidation ability.Moreover,the ultrathin nanosheets and porous structure provided more exposed active sites and facilitated mass and charge transfer.Consequently,S-C_(3)N_(4−y)foam exhibited enhanced photocatalytic activities for synchronous hydrogen evolution(4960μmol/(h·g))and benzylamine oxidation to N-benzylidenebenzylamine(4885μmol/(h·g))with high selectivity of>99%,which were approximately 17.6 and 72.9 times higher than those of bulk CN,respectively.The photocatalytic coupling pairing reaction promotes the water splitting by consuming H2O2,thereby improving the hydrogen evolution efficiency and achieving the production of high value-added imines.This study provides an effective route for regulating the morphology and band structure of carbon nitride for synthesizing highly valuable chemicals.
