Covalent triazine-based frameworks（CTFs） are important microporous materials with a wide range of applications.Here,we demonstrate an environmentally benign and economic synthetic pathway to CTFs.The monomers used f...Covalent triazine-based frameworks（CTFs） are important microporous materials with a wide range of applications.Here,we demonstrate an environmentally benign and economic synthetic pathway to CTFs.The monomers used for CTFs,aromatic nitriles,were obtained by cyanation using nontoxic potassium hexacyanoferrate（Ⅱ） in place of commonly used toxic cyanides.Then,the CTFs were synthesized by trimerization of the corresponding cyano monomers in molten zinc chloride.A series of CTFs was synthesized,and the highest Brunauer-Emmett-Teller surface area measured in this series was 2404 m^2/g.Among the synthesized CTFs,CTF_（DCP） exhibited excellent CO_2 adsorption properties,with a CO_2 uptake of 225 mg/g at 0℃.展开更多
Single-atom catalysts(SACs)have emerged as an advanced frontier in heterogeneous catalysis due to their potential to maximize the atomic efficiency.Herein,covalent triazine-based frameworks(CTFs)confining cobalt singl...Single-atom catalysts(SACs)have emerged as an advanced frontier in heterogeneous catalysis due to their potential to maximize the atomic efficiency.Herein,covalent triazine-based frameworks(CTFs)confining cobalt single atoms(Co-SA/CTF)photocatalysts have been synthesized and used for efficient CO_(2) reduction and hydrogen production under visible light irradiation.The resulted Co-SA/CTF demonstrate excellent photocatalytic activity,with the CO and H2 evolution rates reaching 1665.74μmol g^(−1) h^(−1) and 1293.18μmol g^(−1) h^(−1),respectively,far surpassing those of Co nanoparticles anchored CTF and pure CTF.A variety of instrumental analyses collectively indicated that Co single atoms sites served as the reaction center for activating the adsorbed CO_(2) molecules,which significantly improved the CO_(2) reduction performance.Additionally,the introduction of Co single atoms could accelerate the separation/transfer of photogenerated charge carriers,thus boosting the photocatalytic performance.This study envisions a novel strategy for designing efficient photocatalysts for energy conversion and showcases the application of CTFs as attractive support for confining metal single atoms.展开更多
In this work, a 2D covalent triazine-based framework was prepared by using 1,3-dicyanobenzo[c]thiophene（DCBT） as monomer to effectively capture CO. The resulting CTF-DCBT was characterized by FT-IR, XPS, PXRD, eleme...In this work, a 2D covalent triazine-based framework was prepared by using 1,3-dicyanobenzo[c]thiophene（DCBT） as monomer to effectively capture CO. The resulting CTF-DCBT was characterized by FT-IR, XPS, PXRD, elemental analysis, SEM, TEM, and Nadsorption-desorption.The results indicate that CTF-DCBT is partially crystalline and has ultramicropore（6.5 A?） as well as high heteroatom contents（11.24 wt% and 12.61 wt% for N and S, respectively）. In addition, the BET surface area and total pore volume of CTF-DCBT are 500 m/g and 0.26 cm/g, respectively. CTF-DCBT possesses excellent thermal stability（450 °C） and chemical stability towards boiling water, 4 M HCl, and 1 M Na OH.The COadsorption capacity of CTF-DCBT is 37.8 cm/g at 1 bar and 25 °C. After six adsorption-desorption cycles, there is no obvious loss of COuptake observed. Due to the ultramicropore and high heteroatom contents, CTF-DCBT has high isosteric heats of adsorption for COand high selectivities of COover Nand CH. At 25 °C, the CO/Nand CO/CHselectivities are 112.5 and 10.3, respectively, which are higher than those of most POFs. Breakthrough curves indicate that CTF-DCBT could effectively separate CO/Nand CO/CHmixtures.展开更多
Separation membrane with high flux is generally encouraged in industrial application,because of the tremendous needs for decreasing membrane areas,usage costs and space requirements.The most effective and direct metho...Separation membrane with high flux is generally encouraged in industrial application,because of the tremendous needs for decreasing membrane areas,usage costs and space requirements.The most effective and direct method for obtaining the high flux is to decrease membrane thickness.Polyamide(PA)nanofiltration membrane is conventionally prepared by the direct interfacial polymerization(IP)on substrate surface,and results in a thick PA layer.In this work,we proposed a strategy that constructing triazine-based porous organic polymer(TRZ-POP)as the interlayer to prepare the ultrathin PA nanofiltration membranes.TRZ-POP is firstly deposited on the polyethersulfone substrate,and then the formed TRZ-POP provides more adhesion sites towards PA based on its high specific surface areas.The chemical bonding between terminal amine group of TRZ-POP and the amide group of PA further improves the binding force,and strengthens the stability of PA layer.More importantly,the high porosity of TRZPOP layer causes the higher polymerization of initial PA owning to the stored sufficient amino monomer;and H-bonding interaction between amine groups of TRZ-POP and piperazine(PIP)can astrict the release of PIP.Thus,IP process is controlled,and the thinnest thickness of prepared PA layer is only<15 nm.As expected,PA/TRZ-POP membrane shows a more excellent water flux of 1414 L·m^(-2)·h^(-1)·MPa^(-1)than that of the state-of-the-art nanofiltration membranes,and without sacrificing dye rejection.The build of TRZPOP interlayer develops a new method for obtaining a high-flux nanofiltration membrane.展开更多
Using the bottom-up method, we synthesized a series of perfluorinated covalent triazine-based frameworks(FCTFs) with porous structures for catalysis oxygen reduction reaction(ORR). The evolved FCTFs by high-temperatur...Using the bottom-up method, we synthesized a series of perfluorinated covalent triazine-based frameworks(FCTFs) with porous structures for catalysis oxygen reduction reaction(ORR). The evolved FCTFs by high-temperature carbonization show an apparent variation in electrocatalytic activity toward the ORR dependent on the type of F. The samples synthesized at 900 ℃(FCTF-900) exhibits advantages in terms of high activity, high durability, and methanol-tolerant as an efficient electrocatalyst for ORR, manifests a comparable or even better activity as compared with the commercial Pt/C catalysts not only in alkaline media but also in acidic and neutral electrolyte.展开更多
Triazine(Tz)-based conjugated polymers with redox activity have drawn considerable attention as electrode materials for sustainable rechargeable batteries due to the features such as structural stability and electron-...Triazine(Tz)-based conjugated polymers with redox activity have drawn considerable attention as electrode materials for sustainable rechargeable batteries due to the features such as structural stability and electron-withdrawing nature of the Tz unit.However,it is rather challenging to synthesize highly redox-active Tz-based conjugated polymer electrodes under both ecological and cost-effective conditions.In this study,an ionothermal Friedel-Crafts reaction is developed for the efficient production of redox-active Tz-based conjugated polymers by using an AlCl_(3)-NaCl-KCl eutectic salt as a solvent-catalyst system and polycyclic aromatic compounds with cyanuric chloride as the starting monomers.As proof-of-concept,a series of Tz-based conjugated polymers were synthesized with high yields in the range of 74.8%-94.6%.The resulting Tz-based polymers exhibit excellent electrochemical performance when serving as the cathode materials in rechargeable Al batteries,Na batteries,and aqueous Zn batteries,including high capacities(141.8,163.5,and 161.4 mAh g^(-1),respectively),high operating voltage,as well as fast rate capability.Moreover,the ionothermal-synthesized Tz-based polymers also present much higher redox activity than their counterparts produced under traditional Friedel-Crafts reaction conditions.These results in this work offer a promising pathway to construct highly redox-active Tz-based conjugated polymer electrode materials for sustainable rechargeable batteries.展开更多
Herein,a novel visible-light-responsive photocatalyst with high efficiency was firstly synthesized at room temperature.The mild synthetic method resulted in a uniform spherical triazine-based covalent organic framewor...Herein,a novel visible-light-responsive photocatalyst with high efficiency was firstly synthesized at room temperature.The mild synthetic method resulted in a uniform spherical triazine-based covalent organic framework(TrCOF2)with ultra-high specific surface area as well as chemical stability.Due to the synergistic effect between the self-assembled uniform spherical structure and the abundant triazine-based structure,photoelectron–hole pairs were efficiently separated and migrated on the catalysts.On this basis,TrCOF2 was successfully applied to efficiently degrade bisphenol A(BPA).More than 98%of BPA was deraded after 60 min of visible light treatment,where the active specie of•O_(2)^(−)played a vital role during the degradation of BPA.The holes of TrCOF2 could produce O_(2)by direct reaction with water or hydroxide ions.Simultaneously,photoelectrons can be captured by O_(2)to generate•O_(2)^(−).Moreover,density functional theory(DFT)calculations proved the outstanding ability of the exciting electronic conductivity.Remarkably,a reasonable photocatalytic mechanism for TrCOF2 catalysts was proposed.This research can provide a facile strategy for the synthesis of TrCOFs catalysts at room temperature,which unfolds broad application prospects in the environmental field.展开更多
Our previous study found that the adsorption performance of porous carbon for Gd(Ⅲ) could be significantly improved by increasing the N,and O functional groups on its surface.Unfortunately,the adsorption capacity of ...Our previous study found that the adsorption performance of porous carbon for Gd(Ⅲ) could be significantly improved by increasing the N,and O functional groups on its surface.Unfortunately,the adsorption capacity of porous carbon is low due to the limited number of N,and O functional groups that can be loaded on its surface.Due to the advantage of customizable functional groups of porous organic polymers(POPs),the triazine-based Tb-MEL and hydroxyl-modified triazine-based Tp-MEL were synthesized by a one-step hydrothermal method using nitrogen-rich melamine as the raw material and triformylbenzene(Tb) and 2,4,6-triformylphloroglucinol(Tp),respectively.The Gd(Ⅲ) adsorption isotherms and kinetic curves of Tb-MEL,and Tp-MEL at pH=6 and T=25℃ are in high agreement with the Langmuir isotherm(R^(2)>0.998) and pseudo-second-order kinetics(R^(2)>0.993),respectively.The fitted maximum adsorption capacity(q_(max)) is about 136.05 mg/g,much higher than 58.38 mg/g of Tb-MEL.The adsorption efficiency for Gd(Ⅲ) at pH=7 is close to 100%,and Tp-MEL maintains 62.4% of the initial adsorption capacity after ten cycle s of sorption/desorption of Gd(Ⅲ),with an average elution efficiency of more than 90%.Adsorption selection performance tests show that Tp-MEL has good adsorption selectivity for HREE ions,and the selectivity is as follows:Lu^(3+)>Y^(3+)>Gd^(3+)>Nd^(3+)>La^(3+)>Al^(3+)>Ca^(2+)>Mg^(2+).Batch adsorption,Brunauer-Emmett-Teller(BET) method,and X-ray photoelectron spectrometer(XPS)tests show that hydroxyl modifications lose the specific surface area of the polymer,and the functional groups contribute more to the adsorption performance than the specific surface area.展开更多
Converting CO_(2)into carbonaceous fuels via photocatalysis represents an appealing strategy to simultaneously alleviate the energy crisis and associated environmental problems,yet designing with high photoreduction a...Converting CO_(2)into carbonaceous fuels via photocatalysis represents an appealing strategy to simultaneously alleviate the energy crisis and associated environmental problems,yet designing with high photoreduction activity catalysts remains a compelling challenge.Here,combining the merits of highly porous structure and maximum atomic efficiency,we rationally constructed covalent triazine-based frameworks(CTFs)anchoring copper single atoms(Cu-SA/CTF)photocatalysts for efficient CO_(2)conversion.The Cu single atoms were visualized by high-angle annular dark-field scanning transmission electron microscopy(HAADF-STEM)images and coordination structure of Cu-N-C2 sites was revealed by extended X-ray absorption fine structure(EXAFS)analyses.The as-prepared Cu-SA/CTF photocatalysts exhibited superior photocatalytic CO_(2)conversion to CH4 performance associated with a high selectivity of 98.31%.Significantly,the introduction of Cu single atoms endowed the CuSA/CTF catalysts with increased CO_(2)adsorption capacity,strengthened visible light responsive ability,and improved the photogenerated carriers separation efficiency,thus enhancing the photocatalytic activity.This work provides useful guidelines for designing robust visible light responsive photoreduction CO_(2)catalysts on the atomic scale.展开更多
Pt nanoparticles(PtNPs)as active species have always been considered as one of the best semiconductor materials for photocatalytic hydrogen production.In this study,a Schottky heterojunction has been successfully cons...Pt nanoparticles(PtNPs)as active species have always been considered as one of the best semiconductor materials for photocatalytic hydrogen production.In this study,a Schottky heterojunction has been successfully constructed by evenly loading ultrafine PtNPs onto a triazine-based covalent organic frameworks(COFs).This strategy maintained the high activity of these ultra-small PtNPs while maximizing the utilization of the Pt active sites.The fabricated PtNPs@covalent triazine-based framework-1(CTF-1)composite accomplished a significantly high rate of hydrogen evolution(20.0 mmol·g^(−1)·h^(−1),apparent quantum efficiency(AQE)=7.6%,atλ=450 nm)with 0.40 wt.%Pt loading,giving rise to a 44-fold-increase in the efficiency of the photocatalytic hydrogen production compared to the pristine CTF-1.Theoretical calculations revealed that the strong electron transfer(Q(Pt)=−0.726 qe,in the analysis of Bader charge,Q(Pt)is the charge quantity transferred from Pt cluster to CTF-1,and qe is the unit of charge transfer quantity)between PtNPs and CTF-1 triggers a strong interaction,which makes PtNPs being firmly attached to the structure of CTF-1,thereby enabling high stability and excellent hydrogen production efficiency.Importantly,the hydrogen binding free energy(ΔGH*)of PtNPs@CTF-1 is much lower than that of the unmodified CTF-1,leading to a much lower intermediate state and hence a significant improvement in photocatalytic performance.The overall findings of this work provide a new platform to incorporate metallic NPs into COFs for the design and fabrication of highly efficient photocatalysts.展开更多
基金supported by the National Natural Science Foundation of China(21373202,21525315)~~
文摘Covalent triazine-based frameworks（CTFs） are important microporous materials with a wide range of applications.Here,we demonstrate an environmentally benign and economic synthetic pathway to CTFs.The monomers used for CTFs,aromatic nitriles,were obtained by cyanation using nontoxic potassium hexacyanoferrate（Ⅱ） in place of commonly used toxic cyanides.Then,the CTFs were synthesized by trimerization of the corresponding cyano monomers in molten zinc chloride.A series of CTFs was synthesized,and the highest Brunauer-Emmett-Teller surface area measured in this series was 2404 m^2/g.Among the synthesized CTFs,CTF_（DCP） exhibited excellent CO_2 adsorption properties,with a CO_2 uptake of 225 mg/g at 0℃.
基金financially supported by the National Natural Science Foundation of China(Nos.51672047,21707173)the Youth Talent Support Program of Fujian Province(00387077)the National Natural Science Foundation of Fujian Province(Nos.2019J01648,2019J01226)。
文摘Single-atom catalysts(SACs)have emerged as an advanced frontier in heterogeneous catalysis due to their potential to maximize the atomic efficiency.Herein,covalent triazine-based frameworks(CTFs)confining cobalt single atoms(Co-SA/CTF)photocatalysts have been synthesized and used for efficient CO_(2) reduction and hydrogen production under visible light irradiation.The resulted Co-SA/CTF demonstrate excellent photocatalytic activity,with the CO and H2 evolution rates reaching 1665.74μmol g^(−1) h^(−1) and 1293.18μmol g^(−1) h^(−1),respectively,far surpassing those of Co nanoparticles anchored CTF and pure CTF.A variety of instrumental analyses collectively indicated that Co single atoms sites served as the reaction center for activating the adsorbed CO_(2) molecules,which significantly improved the CO_(2) reduction performance.Additionally,the introduction of Co single atoms could accelerate the separation/transfer of photogenerated charge carriers,thus boosting the photocatalytic performance.This study envisions a novel strategy for designing efficient photocatalysts for energy conversion and showcases the application of CTFs as attractive support for confining metal single atoms.
基金supported by the National Key R&D Program of China(2016YFB0600901)the Natural Science Foundation of China(grant nos.21536001 and 21606007)
文摘In this work, a 2D covalent triazine-based framework was prepared by using 1,3-dicyanobenzo[c]thiophene（DCBT） as monomer to effectively capture CO. The resulting CTF-DCBT was characterized by FT-IR, XPS, PXRD, elemental analysis, SEM, TEM, and Nadsorption-desorption.The results indicate that CTF-DCBT is partially crystalline and has ultramicropore（6.5 A?） as well as high heteroatom contents（11.24 wt% and 12.61 wt% for N and S, respectively）. In addition, the BET surface area and total pore volume of CTF-DCBT are 500 m/g and 0.26 cm/g, respectively. CTF-DCBT possesses excellent thermal stability（450 °C） and chemical stability towards boiling water, 4 M HCl, and 1 M Na OH.The COadsorption capacity of CTF-DCBT is 37.8 cm/g at 1 bar and 25 °C. After six adsorption-desorption cycles, there is no obvious loss of COuptake observed. Due to the ultramicropore and high heteroatom contents, CTF-DCBT has high isosteric heats of adsorption for COand high selectivities of COover Nand CH. At 25 °C, the CO/Nand CO/CHselectivities are 112.5 and 10.3, respectively, which are higher than those of most POFs. Breakthrough curves indicate that CTF-DCBT could effectively separate CO/Nand CO/CHmixtures.
基金funded by National Key Research and Development Program of China (2021YFC2101202)Bingtuan Science and Technology Program (2022DB025)+3 种基金Beijing Natural Science Foundation (2222015)Hebei Province Key Research and Development Program (21327316D)China Postdoctoral Science Foundation (2021M700011)the long-term subsidy mechanism from the Ministry of Finance and the Ministry of Education of China。
文摘Separation membrane with high flux is generally encouraged in industrial application,because of the tremendous needs for decreasing membrane areas,usage costs and space requirements.The most effective and direct method for obtaining the high flux is to decrease membrane thickness.Polyamide(PA)nanofiltration membrane is conventionally prepared by the direct interfacial polymerization(IP)on substrate surface,and results in a thick PA layer.In this work,we proposed a strategy that constructing triazine-based porous organic polymer(TRZ-POP)as the interlayer to prepare the ultrathin PA nanofiltration membranes.TRZ-POP is firstly deposited on the polyethersulfone substrate,and then the formed TRZ-POP provides more adhesion sites towards PA based on its high specific surface areas.The chemical bonding between terminal amine group of TRZ-POP and the amide group of PA further improves the binding force,and strengthens the stability of PA layer.More importantly,the high porosity of TRZPOP layer causes the higher polymerization of initial PA owning to the stored sufficient amino monomer;and H-bonding interaction between amine groups of TRZ-POP and piperazine(PIP)can astrict the release of PIP.Thus,IP process is controlled,and the thinnest thickness of prepared PA layer is only<15 nm.As expected,PA/TRZ-POP membrane shows a more excellent water flux of 1414 L·m^(-2)·h^(-1)·MPa^(-1)than that of the state-of-the-art nanofiltration membranes,and without sacrificing dye rejection.The build of TRZPOP interlayer develops a new method for obtaining a high-flux nanofiltration membrane.
基金Supported by the 1000 Plan Professorship for Young Talents,Hundred Talents Program of Fujian Provincethe Fujian Science and Technology Key Project(Item Number 2016H0043)
文摘Using the bottom-up method, we synthesized a series of perfluorinated covalent triazine-based frameworks(FCTFs) with porous structures for catalysis oxygen reduction reaction(ORR). The evolved FCTFs by high-temperature carbonization show an apparent variation in electrocatalytic activity toward the ORR dependent on the type of F. The samples synthesized at 900 ℃(FCTF-900) exhibits advantages in terms of high activity, high durability, and methanol-tolerant as an efficient electrocatalyst for ORR, manifests a comparable or even better activity as compared with the commercial Pt/C catalysts not only in alkaline media but also in acidic and neutral electrolyte.
基金supported by the National Natural Science Foundation of China(52103264,22175110,22375076)the Hubei Provincial Natural Science Foundation of China(2024AFA031)+2 种基金the Fundamental Innovation Project in the School of Materials Science and Engineeringthe Fundamental Research Funds for the Central Universities(GK202501012,GK202202001)the Science and Technology Innovation Team of Shaanxi Province(2023-CX-TD-27)。
文摘Triazine(Tz)-based conjugated polymers with redox activity have drawn considerable attention as electrode materials for sustainable rechargeable batteries due to the features such as structural stability and electron-withdrawing nature of the Tz unit.However,it is rather challenging to synthesize highly redox-active Tz-based conjugated polymer electrodes under both ecological and cost-effective conditions.In this study,an ionothermal Friedel-Crafts reaction is developed for the efficient production of redox-active Tz-based conjugated polymers by using an AlCl_(3)-NaCl-KCl eutectic salt as a solvent-catalyst system and polycyclic aromatic compounds with cyanuric chloride as the starting monomers.As proof-of-concept,a series of Tz-based conjugated polymers were synthesized with high yields in the range of 74.8%-94.6%.The resulting Tz-based polymers exhibit excellent electrochemical performance when serving as the cathode materials in rechargeable Al batteries,Na batteries,and aqueous Zn batteries,including high capacities(141.8,163.5,and 161.4 mAh g^(-1),respectively),high operating voltage,as well as fast rate capability.Moreover,the ionothermal-synthesized Tz-based polymers also present much higher redox activity than their counterparts produced under traditional Friedel-Crafts reaction conditions.These results in this work offer a promising pathway to construct highly redox-active Tz-based conjugated polymer electrode materials for sustainable rechargeable batteries.
基金Environmental Protection Department of Hubei Province(No.2017HB04)the Fundamental Research Funds for the Central Universities,China University of Geosciences,Wuhan(No.CUG170102).
文摘Herein,a novel visible-light-responsive photocatalyst with high efficiency was firstly synthesized at room temperature.The mild synthetic method resulted in a uniform spherical triazine-based covalent organic framework(TrCOF2)with ultra-high specific surface area as well as chemical stability.Due to the synergistic effect between the self-assembled uniform spherical structure and the abundant triazine-based structure,photoelectron–hole pairs were efficiently separated and migrated on the catalysts.On this basis,TrCOF2 was successfully applied to efficiently degrade bisphenol A(BPA).More than 98%of BPA was deraded after 60 min of visible light treatment,where the active specie of•O_(2)^(−)played a vital role during the degradation of BPA.The holes of TrCOF2 could produce O_(2)by direct reaction with water or hydroxide ions.Simultaneously,photoelectrons can be captured by O_(2)to generate•O_(2)^(−).Moreover,density functional theory(DFT)calculations proved the outstanding ability of the exciting electronic conductivity.Remarkably,a reasonable photocatalytic mechanism for TrCOF2 catalysts was proposed.This research can provide a facile strategy for the synthesis of TrCOFs catalysts at room temperature,which unfolds broad application prospects in the environmental field.
基金supported by the National Natural Science Foundation of China (41662004)。
文摘Our previous study found that the adsorption performance of porous carbon for Gd(Ⅲ) could be significantly improved by increasing the N,and O functional groups on its surface.Unfortunately,the adsorption capacity of porous carbon is low due to the limited number of N,and O functional groups that can be loaded on its surface.Due to the advantage of customizable functional groups of porous organic polymers(POPs),the triazine-based Tb-MEL and hydroxyl-modified triazine-based Tp-MEL were synthesized by a one-step hydrothermal method using nitrogen-rich melamine as the raw material and triformylbenzene(Tb) and 2,4,6-triformylphloroglucinol(Tp),respectively.The Gd(Ⅲ) adsorption isotherms and kinetic curves of Tb-MEL,and Tp-MEL at pH=6 and T=25℃ are in high agreement with the Langmuir isotherm(R^(2)>0.998) and pseudo-second-order kinetics(R^(2)>0.993),respectively.The fitted maximum adsorption capacity(q_(max)) is about 136.05 mg/g,much higher than 58.38 mg/g of Tb-MEL.The adsorption efficiency for Gd(Ⅲ) at pH=7 is close to 100%,and Tp-MEL maintains 62.4% of the initial adsorption capacity after ten cycle s of sorption/desorption of Gd(Ⅲ),with an average elution efficiency of more than 90%.Adsorption selection performance tests show that Tp-MEL has good adsorption selectivity for HREE ions,and the selectivity is as follows:Lu^(3+)>Y^(3+)>Gd^(3+)>Nd^(3+)>La^(3+)>Al^(3+)>Ca^(2+)>Mg^(2+).Batch adsorption,Brunauer-Emmett-Teller(BET) method,and X-ray photoelectron spectrometer(XPS)tests show that hydroxyl modifications lose the specific surface area of the polymer,and the functional groups contribute more to the adsorption performance than the specific surface area.
基金the National Natural Science Foundation of China(Nos.51672047,21707173,and 21701168)Dalian high level talent innovation project(No.2019RQ063)+2 种基金the National Natural Science Foundation of Fujian Province(Nos.2019J01648 and 2019J01226)Open project Foundation of State Key Laboratory of Structural Chemistry,Fujian Institute of Research on the Structure of Matter,Chinese Academy of Sciences(No.20200021)the Youth Talent Support Program of Fujian Province(No.00387077).
文摘Converting CO_(2)into carbonaceous fuels via photocatalysis represents an appealing strategy to simultaneously alleviate the energy crisis and associated environmental problems,yet designing with high photoreduction activity catalysts remains a compelling challenge.Here,combining the merits of highly porous structure and maximum atomic efficiency,we rationally constructed covalent triazine-based frameworks(CTFs)anchoring copper single atoms(Cu-SA/CTF)photocatalysts for efficient CO_(2)conversion.The Cu single atoms were visualized by high-angle annular dark-field scanning transmission electron microscopy(HAADF-STEM)images and coordination structure of Cu-N-C2 sites was revealed by extended X-ray absorption fine structure(EXAFS)analyses.The as-prepared Cu-SA/CTF photocatalysts exhibited superior photocatalytic CO_(2)conversion to CH4 performance associated with a high selectivity of 98.31%.Significantly,the introduction of Cu single atoms endowed the CuSA/CTF catalysts with increased CO_(2)adsorption capacity,strengthened visible light responsive ability,and improved the photogenerated carriers separation efficiency,thus enhancing the photocatalytic activity.This work provides useful guidelines for designing robust visible light responsive photoreduction CO_(2)catalysts on the atomic scale.
基金the National Natural Science Foundation of China(Nos.22271022 and 21701016)the Science and Technology Development Planning of Jilin Province(No.YDZJ202201ZYTS342)+1 种基金the China Scholarship Council(CSC No.201802335014)Partial support from the Robert A.Welch Foundation(B-0027)(S.M.)and Researchers Supporting Program(No.RSP-2024R55)at King Saud University,Riyadh,Saudi Arabia is also acknowledged.
文摘Pt nanoparticles(PtNPs)as active species have always been considered as one of the best semiconductor materials for photocatalytic hydrogen production.In this study,a Schottky heterojunction has been successfully constructed by evenly loading ultrafine PtNPs onto a triazine-based covalent organic frameworks(COFs).This strategy maintained the high activity of these ultra-small PtNPs while maximizing the utilization of the Pt active sites.The fabricated PtNPs@covalent triazine-based framework-1(CTF-1)composite accomplished a significantly high rate of hydrogen evolution(20.0 mmol·g^(−1)·h^(−1),apparent quantum efficiency(AQE)=7.6%,atλ=450 nm)with 0.40 wt.%Pt loading,giving rise to a 44-fold-increase in the efficiency of the photocatalytic hydrogen production compared to the pristine CTF-1.Theoretical calculations revealed that the strong electron transfer(Q(Pt)=−0.726 qe,in the analysis of Bader charge,Q(Pt)is the charge quantity transferred from Pt cluster to CTF-1,and qe is the unit of charge transfer quantity)between PtNPs and CTF-1 triggers a strong interaction,which makes PtNPs being firmly attached to the structure of CTF-1,thereby enabling high stability and excellent hydrogen production efficiency.Importantly,the hydrogen binding free energy(ΔGH*)of PtNPs@CTF-1 is much lower than that of the unmodified CTF-1,leading to a much lower intermediate state and hence a significant improvement in photocatalytic performance.The overall findings of this work provide a new platform to incorporate metallic NPs into COFs for the design and fabrication of highly efficient photocatalysts.
