The high conductivity of electrocatalyst can eliminate the Schottky energy barrier at the interface of heterogeneous phases during an electrocatalytic reaction and accelerate the rapid electron transfer to the catalyt...The high conductivity of electrocatalyst can eliminate the Schottky energy barrier at the interface of heterogeneous phases during an electrocatalytic reaction and accelerate the rapid electron transfer to the catalytic active center.Therefore,the electronic conductivity is a vital parameter for oxygen reduction reaction(ORR).Covalent triazine frameworks(CTFs)have shown great potential application as electrocatalysts in ORR with a merit of the diverse building blocks.However,the intrinsic low conductivity and high impedance of CTFs could be significant setbacks in electrocatalytic application.Herein,CTFs were constructed by introducing F and N co-modification for efficient 2e^(-)ORR.Compared with the pristine CTF,the co-presence of F,N could increase the conductivity obviously by 1000-fold.As a result,F-N-CTF exhibits enhanced catalytic performance of H_(2)O_(2)generation and selectivity towards reaction pathways.This work reveals the importance of conductivity optimization for CTFs and provides guidance for designing high conductivity non-metallic organic semiconductor catalysts for 2e^(-)ORR.展开更多
Solar‐driven CO_(2)conversion to precious fossil fuels has been proved to become a potential way to decrease CO_(2)with producing renewable fuels,which mainly relies on photocatalysts with efficient charge separation...Solar‐driven CO_(2)conversion to precious fossil fuels has been proved to become a potential way to decrease CO_(2)with producing renewable fuels,which mainly relies on photocatalysts with efficient charge separation.In this work,a metal free heterostructure of covalent triazine framework(CTF)and graphite carbon nitride(g‐C_(3)N_(4),abbreviated as CN)is applied in the CO_(2)photoreduction for the first time.Detailed characterization methods such as photoluminescence(PL)and time‐resolved PL(TR‐PL)decay are utilized to reveal the photo‐induced carries separating process on g‐C_(3)N_(4)/CTF(CN/CTF)heterostructure.The introduced CTF demonstrated a great boosting photocatalytic activity for CN,bringing about the transform rates of CO_(2)to CO reaching 151.1μmol/(g·h)with a 30 h stabilization time,while negligible CH_(4)was detected.The optimal CN/CTF heterostructure could more efficiently separate charges with a lower probability of recombination under visible light irradiation,which made the photoreduction efficiency of CO_(2)to CO be 25.5 and 2.5 times higher than that of CTF and CN,respectively.This investigation is expected to offer a new thought for fabricating high‐efficiency photocatalyst without metal in solar‐energy‐driven CO_(2)reduction.展开更多
The photocatalytic production of syngas using a noble-metal-free catalytic system is a promising approach for renewable energy and environmental sustainability.In this study,we demonstrate an efficient catalytic syste...The photocatalytic production of syngas using a noble-metal-free catalytic system is a promising approach for renewable energy and environmental sustainability.In this study,we demonstrate an efficient catalytic system formed by integrating Co single sites,which act as the active sites,in covalent triazine frameworks(CTFs),which act as the photoabsorber,for the photocatalytic production of syngas from CO2 in aqueous solution.The enhanced light absorption of the CTFs,which contain intramolecular heterojunctions,in conjunction with 0.8 mmol L^‒1 of the Co complex enables excellent syngas production with a yield of 3303μmol g‒1(CO:H2=1.4:1)in 10 h,which is about three times greater than that achieved using CTF without a heterojunction.In the photocatalytic reaction,the coordinated single Co centers accept the photogenerated electrons from the CTF,and serve as active sites for CO2 conversion through an adsorption-activation-reaction mechanism.Theoretical calculations further reveal that the intramolecular heterojunctions highly promote photogenerated charge separation,thus boosting photocatalytic syngas production.This work reveals the promising potential of CTFs for single-metal-site-based photocatalysis.展开更多
Carbon super-heterostructures with high nitrogen contents from the covalent hybrid precursors of covalent triazine frameworks(CTFs)and zeolitic imidazolic frameworks(ZIFs)are scarcely explored because of CTF's ord...Carbon super-heterostructures with high nitrogen contents from the covalent hybrid precursors of covalent triazine frameworks(CTFs)and zeolitic imidazolic frameworks(ZIFs)are scarcely explored because of CTF's ordered structure and toxic superacid that dissolves or destabilizes the metal nodes.To solve this problem,herein,we report a straightforward two-step pathway for the covalent hybridization of disordered CTF(d–CTF)–ZIF composites via preincorporation of an imidazole(IM)linker into ordered CTFs,followed by the imidazole-site-specific covalent growth of ZIFs.Direct carbonization of these synthesized d–CTF−IM−ZIF hybrids results in unique hollow carbon super-heterostructures with ultrahigh nitrogen content(>18.6%),high specific surface area(1663m^(2)g^(−1)),and beneficial trace metal(Co/Zn NPs)contents for promoting the redox pseudocapacitance.As proof of concept,the obtained carbon super-heterostructure(Co–Zn–NC_(SNH)–800)is used as a positive electrode in an asymmetric supercapacitor,demonstrating a remarkable energy density of 61Wh kg^(−1)and extraordinary cyclic stability of 97%retention after 30,000 cycles at the cell level.Our presynthetic modifications of CTF and their covalent hybridization with ZIF crystals pave the way toward new design strategies for synthesizing functional porous carbon materials for promising energy applications.展开更多
Porous polymer(pyrrolopyrrole)was successfully prepared via domino-ring-formation reaction.The chemical-physical properties of cyanided covalent triazine frameworks(CTF-CN)were characteriazed by fourier transform infr...Porous polymer(pyrrolopyrrole)was successfully prepared via domino-ring-formation reaction.The chemical-physical properties of cyanided covalent triazine frameworks(CTF-CN)were characteriazed by fourier transform infrared spectra(FT-IR),scanning electron microscopy(SEM),nuclear magnetic resonance(NMR),specific surface area analyzer(BET)and thermogravimetric analysis(TGA),respectively.The experimental results of adsorption of chloranil(TCBQ)in aqueous solution indicated that CTF-CN exhibited distinctive adsorption capacity toward TCBQ owing to its large specific surface area.Specifically,the adsorption equilibrium of as-prepared polymer was executed within 5 h and the calculated adsorption capacity was 499.76 mg/g.Furthermore,the adsorption kinetics could be well defined with the linear pseudo-second-order model,which implies that the chemical interaction are relative important in the course of TCBQ removal.Finally,the current studies verify that CTF-CN has unique rigid and nano-porous framework structure,which can be employed for the treatment of a series of harmful aromatic substances.展开更多
Photocatalysis using the abundant solar energy is an environmentally friendly and efficient way to degrade organic matter.Covalent triazine frameworks(CTFs),a new class of metal-free organic semiconductors responsive ...Photocatalysis using the abundant solar energy is an environmentally friendly and efficient way to degrade organic matter.Covalent triazine frameworks(CTFs),a new class of metal-free organic semiconductors responsive to visible light,are promising materials for water treatment.In this study,an original CTF,namely CTF-1,was modified by S-doping to form CTFSx,which were used as metal-free catalysts for degradation of methyl orange(MO)and bisphenol A(BPA).The outcomes demonstrated that the photocatalytic degradation of MO and BPA by CTFSxwas superior to that by CTF-1,with better stability and reusability.Within 6 h,53.2%MO and 84.7%BPA were degraded by CTFS5,and the degradation rate constants were 0.145 h-1and 0.29 h-1,respectively,which were 3.6 and 5.8 times higher than those of CTF-1.Further investigation revealed that enhanced visible light absorption,a reduced degree of free carrier recombination,rapid separation and transfer of photogenerated electrons and holes,and improved·OH oxidation capacity were important factors contributing to the significantly enhanced photocatalytic activity.The S-doping method effectively improved the light absorption performance,electronic structure,and modulation band structure of CTF-1.This work highlights the potential application of low-cost metal-free catalysts driven by visible light for the removal of organic pollutants from wastewater.展开更多
In recent years,photocatalysis with efficient,low-cost and stable metal-free catalysts is one of the most promising technologies for non-polluting energy production and resource-economic environment purifying.Benefiti...In recent years,photocatalysis with efficient,low-cost and stable metal-free catalysts is one of the most promising technologies for non-polluting energy production and resource-economic environment purifying.Benefiting from the molecularly precise backbones,regular and homogeneous porosity,lightelement composition,nitrogen-rich system with unique electronic band structure of two-dimensional(2D)covalent triazine framework(CTF),as well as the huge specific surface area,superior thermal conductivity,excellent carrier mobility and mechanical properties of 2D graphene,CTF/graphene hybrid-based photocatalysts show great application potential in the field of photocatalysis.In this review,the recent development in synthesis of CTF/graphene hybrid-based photocatalysts,and their applications in photocatalytic water splitting for hydrogen production and photocatalytic degradation of pollutants are summarized.Firstly,we briefly describe the molecular structures,physicochemical properties,and synthetic strategies for CTF/graphene hybrid-based photocatalysts including solution mixing method,in-situ polymerization method and sol-gel method.We further assess the impact of different preparation methods on the structure,morphology,and interacting model between CTF and graphene in CTF/graphene hybrids.Following the various preparation process for CTF/graphene hybrid-based photocatalysts,these methods are analyzed and compared regarding their merits and demerits.Secondly,the functions of CTF/graphene hybrid-based photocatalysts obtained from different synthesis approaches that enhance the catalytic activity for photocataLytic hydrogen evolution and photocatalytic degradation of pollutants are discussed from the three aspects of light harvesting,charge separation and transfer,and surface catalysis.Particular focus has been placed on the catalytic mechanisms of CTF/graphene hybridbased photocatalysts for enhanced photocatalytic hydrogen evolution and improved photocatalytic degradation of pollutants.Then the rational manipulation of selection and building units of CTF,connecting bonds between CTF and graphene,dimensions and pore structures of CTF/graphene hybrids in design of CTF/graphene hybrid-based photocatalysts is discussed,aiming to inspire critical thinking about the effective strategies for modification of photocatalysts rather than the development of novel materials.In the end,the challenges and some future trends of CTF/graphene hybrids as advanced photocatalysts are also discussed from three aspects:catalysts design,performance stability and reaction mechanism.The approaches offer potential solutions to address the challenges of largescale production,catalyst activity and stability in the further research and development of new types of metal-free hybrid photocatalysts with high efficiency.展开更多
Controllable fabrication of multi-electroactive sites and morphology-ordered carbon electrodes with excellent capacity and alleviating self-discharge behavior for aqueous redox-enhanced supercapacitors(SCRE)is highly ...Controllable fabrication of multi-electroactive sites and morphology-ordered carbon electrodes with excellent capacity and alleviating self-discharge behavior for aqueous redox-enhanced supercapacitors(SCRE)is highly desirable but still challenging.Herein,the N/P/S-rich carbon nanosheets with ultrathin thickness(2–3 nm)and hierarchical porous structure are successfully prepared via phytic acid-driven interfacial phosphorization strategy using S-bridged covalent triazine framework nanosheets(CTFS)as precursor,which are synthesized through a eutectic molten salt-induced ionothermal polymerization.The carbon electrode with adequate N/P/S active sites is pioneeringly introduced in SCRE,clarifying that the coupling hierarchical porous structure and multi-electroactive sites can effectively enhance the interface interaction between carbon electrodes and redox electrolytes via the ex-situ characterizations and theoretical calculations.Consequently,the resultant N/P/S-rich carbon nanosheet(PCTFSC)enables SCRE in KI-doped H2SO4 electrolyte to achieve state-of-the-art specific capacity(1586 mA·h·g^(-1) at 1 A·g^(-1))with 60%of capacity retention at 16 A·g^(-1) and ultra-high energy density of 816 Wh·kg–1,exceeding the reported aqueous supercapacitors thus far.Moreover,the PCTFS based SCRE also exhibits a low self-discharge rate(holding 50%of open circuit potential after 15 h).This study provides new insights to design and regulate advanced carbon materials from the atom level and nano-morphology toward high performance SCRE.展开更多
Covalent triazine frameworks(CTFs),known as highly conjugated layered solids,have garnered significant interest due to their distinctive structural and property characteristics.However,the exfoliation of CTF solids to...Covalent triazine frameworks(CTFs),known as highly conjugated layered solids,have garnered significant interest due to their distinctive structural and property characteristics.However,the exfoliation of CTF solids towards nanoCTFs in high yields is currently inadequate and inefficient,limiting their utility.This study presents the design and synthesis of CTFs containing non-crystalline regions and their random stacks using a methyl-containing nitrile monomer.Incorporating in-plane methyl groups enhances the polarity of CTFs and disrupts layered interactions,facilitating smooth exfoliation under competing solvent-layer interactions and producing nanocolloids in dilute dispersions.Furthermore,CTFs can rapidly disperse in DMF at a high concentration,enabling the formation of CTF organogel for the first time.Additionally,the designed CTF nanocolloids allow for the first simple physical modification of carbon nanotubes.The assembly,associated with conjugated features,enables the fabrication of CTF/carbon nanotube organogel.展开更多
Robust covalent organic frameworks(COFs)with abundant redox-active sites have attracted intense attention for organic cathode materials due to the ordered structure and excellent stability.Herein,a two-dimensional(2D)...Robust covalent organic frameworks(COFs)with abundant redox-active sites have attracted intense attention for organic cathode materials due to the ordered structure and excellent stability.Herein,a two-dimensional(2D)crystalline copper-porphyrin covalent triazine framework(CuBCPP-CTF)was synthesized via polycondensation of 5,15-bis(4-cyanophenyl)porphyrin(H_(2)BCPP)and followed by post-copperization.The integration of copper-porphyrin moieties and triazine linkages provides two kinds of functional sites for outstanding Li+and PF6−ions storage.Electrochemical studies reveal a high discharge capacity of 232 mAh·g^(−1)at 200 mA·g^(−1)and high mid-point voltage(2.77 V vs.Li^(+)/Li),corresponding to an outstanding energy density of 601 Wh·kg^(−1).Density functional theory calculations and ex-situ characterizations disclose the intrinsic bipolar redox mechanism of metalloporphyrin for both PF6−and Li^(+)accommodation and p-type triazine units for PF_(6)^(−)storage.展开更多
Electroreduction of CO_(2)into chemicals is of great importance in the global carbon balance.Although noble-metal based catalysts and single-atom catalysts(SACs)are known to be active for CO_(2)electroreduction reacti...Electroreduction of CO_(2)into chemicals is of great importance in the global carbon balance.Although noble-metal based catalysts and single-atom catalysts(SACs)are known to be active for CO_(2)electroreduction reaction(CO_(2)RR),the high cost of noble-metal and the lack of effective synthesis approaches to prepare SACs have tremendously hindered the application.Non-metal doped carbon materials have attracted great interest because of their reasonable cost,chemical stability and excellent electrical conductivity.Nevertheless,the design and fabrication of highly efficient non-metal doped carbon electrocatalysts for CO_(2)RR to meet industry demands still remains a big challenge.Herein,triphenylphosphine@covalent triazine frameworks(CTFs)composites were employed as precursors to fabricate N,P dual-doped porous carbon catalysts PCTF-X-Y(X represents the carbonization temperature,and Y represents the mass ratio of CTF to triphenylphosphine)for CO_(2)RR.Due to the high specific surface areas and synergistic effect between N and P,the obtained PCTF-1000-5 exhibited high selectivity for CO production up to 84.3%at–0.7 V versus the reversible hydrogen electrode(vs.RHE)and long-term durability over 16 h,which are better than the reported N,P dual-doped carbon catalysts in aqueous media.This work provides a new way to design and fabricate non-metal catalysts for electrocatalysis.展开更多
Crystallization is an unsolved challenge in the chemistry of covalent triazine frameworks(CTFs) due to the poorly controlled simultaneous polymerization and crystallization processes. Herein, the synthesis of crystall...Crystallization is an unsolved challenge in the chemistry of covalent triazine frameworks(CTFs) due to the poorly controlled simultaneous polymerization and crystallization processes. Herein, the synthesis of crystalline CTFs via the introduction of aliphatic amine as a dynamic modulator is reported. By optimizing the amount of aliphatic amine, the crystallization process can be controlled in an open system, resulting in the synthesis of crystalline CTFs. These crystalline CTFs exhibit much better photocatalytic hydrogen evolution performance, with highly ordered CTF-1-C3 demonstrating superior performance(10 mmol g^(-1)h^(-1)) compared with most reported CTF-1. This approach also allows for the preparation of various crystalline CTFs.展开更多
Single cobalt atom is promising non-precious metal catalyst instead of Pt in the oxygen reduction reaction(ORR).However,it is still a great challenge to develop a costeffective,ultrastable and efficent single-atom cob...Single cobalt atom is promising non-precious metal catalyst instead of Pt in the oxygen reduction reaction(ORR).However,it is still a great challenge to develop a costeffective,ultrastable and efficent single-atom cobalt catalyst for ORR,requiring efficient fabrication strategies and robust support to stabilize the single cobalt atom.Here,we prepared a highly active and stable atomically isolated cobalt catalyst via covalent triazine framework(CTF)support with Ketjen Black(KB)hybridization in scale.The prepared single Co catalyst(Co-CTF/KB)possesses high metal loading over 4 wt%and shows superior ORR performance with a half-wave potential(E1/2)of 0.830 V and a limiting current density of 6.14 mA cm-2 as well as high tolerance of methanol in an alkaline medium,which outperforms commercial Pt/C and most non-precious-metal catalysts reported to date.Benefiting from strong stabilization of Co atoms on CTF,Co-CTF/KB shows outstanding stability with only 5 mV negative shifts after 10,000 cycles.Moreover,it also displays high catalytic activity for oxygen evolution reaction(OER),suggesting it is an efficient ORR/OER bifunctional catalyst.The present work provides a facile strategy for preparing single-atom catalysts in bulk quantity and contributes to development of catalysts for electrochemical conversion and storage devices.展开更多
A highly conjugated network of covalent triazine frameworks(CTFs)on the one hand promotes light-harvesting,but on the other hand,also results in high carrier recombination which eventually limits their photocatalytic ...A highly conjugated network of covalent triazine frameworks(CTFs)on the one hand promotes light-harvesting,but on the other hand,also results in high carrier recombination which eventually limits their photocatalytic hydrogen evolution reaction(HER)rates.Thus,strategies to favorably tune the electronic configuration of CTFs for efficient photocatalytic HERs need to be developed,but still remain challenging.Herein,a simple in-situ defect strategy involving element doping is developed for the first time to introduce a heteroatom including S and Se into CTF-1 via the condensation of aldehydes with the mixture of the terephthalimidamide and the S-or Se-substituted terephthalimidamide under mild conditions.The doping content(X)is varied,resulting in a series of S-and Se-doped CTFs,named CTFS-1-X and CTFSe-1-X,respectively.Interestingly,for the S-doped CTFs,CTFS-1-10 shows the most excellent HER rate(4,992.3μmol g^(-1)h^(-1))from water splitting,while for the Se-doped ones,CTFSe-1-10 exhibits a photocatalytic HER rate of 5,792.8μmol g^(-1)h^(-1),both of which far surpass undoped CTFs(693.3μmol g^(-1)h^(-1)).In-depth studies indicate that the introduction of S or Se atoms into CTFs could extend the light absorption and promote photo-generated electron-hole pairs migration.Meanwhile,S-or Se-doping could create heterogeneous electronic configuration in CTFs,which can help to suppress carrier recombination.展开更多
Tandem catalytic reactions have attracted extensive interest because of their ability to reduce reaction steps,energy consumption,and waste.However,the construction of highly efficient tandem catalytic systems is stil...Tandem catalytic reactions have attracted extensive interest because of their ability to reduce reaction steps,energy consumption,and waste.However,the construction of highly efficient tandem catalytic systems is still a significant challenge due to the problematic integration of multiple active sites in one reaction system and the incompatibility of different reaction conditions.Although metal nanoparticles(MNPs)supported on porous framework materials have shown excellent catalytic performances in various reactions,their cooperative catalysis for tandem reactions is rarely reported.展开更多
Covalent triazine frameworks(CTFs)have been recently employed for visible light-driven photocatalysis due to their unique optical and electronic properties.However,the usually highly hydrophobic nature of CTFs,which o...Covalent triazine frameworks(CTFs)have been recently employed for visible light-driven photocatalysis due to their unique optical and electronic properties.However,the usually highly hydrophobic nature of CTFs,which originates from their overall aromatic backbone,leads to limitations of CTFs for applications in aqueous media.In this study,we aim to extend the range of the application media of CTFs and design hybrid material of a CTF and mesoporous silica(SBA-15)for efficient photocatalysis in aqueous medium.A thiophene-containing CTF was directly synthesized in mesopores of SBA-15.Due to the high surface area and the added hydrophilic properties by silica,the hybrid material demonstrated excellent adsorption of organic molecules in water.This leads not only to high photocatalytic performance of the hybrid material for the degradation of organic dyes in water,but also for efficient photocatalysis in solvent-free and solid state.Furthermore,the reusability,stability and easy recovery of the hybrid material offers promising metal-free heterogeneous photocatalyst for broader applications in different reaction media.展开更多
Porous organic polymers(POPs)are an emerging class of porous materials,having many promising applications in a variety of areas.Among them,covalent triazine frameworks(CTFs)featuring conjugated and porous structures c...Porous organic polymers(POPs)are an emerging class of porous materials,having many promising applications in a variety of areas.Among them,covalent triazine frameworks(CTFs)featuring conjugated and porous structures can be well applied in optoelectronics.To achieve high optoelectronic performance,usually the design and synthesis of CTFs based on appropriate building blocks is critical.Here we report the synthesis of two fluorescent CTFs based on typical fluorescent building blocks,in which CTF-Py constructed from a pyrene(Py)building block was reported for the first time,showing prospective applications in the sensing of nitroaromatics with high sensitivity,and photocatalytic water splitting and carbon dioxide reduction with high performance in comparison with other porous organic materials.展开更多
Covalent triazine frameworks(CTFs)are a class of unique two-dimensional nitrogen-rich triazine framework with adjustable chemical and electronic structures,rich porosity,good stability and excellent semiconductivity,w...Covalent triazine frameworks(CTFs)are a class of unique two-dimensional nitrogen-rich triazine framework with adjustable chemical and electronic structures,rich porosity,good stability and excellent semiconductivity,which enable great various applications in efficient gas/molecular adsorption and separation,energy storage and conversion,especially photo-and electrocatalysis.Different synthesis strategies strongly affect the morphology of CTFs and play an important role in their structure and properties.In this concept,we provide a comprehensive and systematic review of the synthesis methods such as ionothermal synthesis,phosphorus pentoxide catalytic method,polycondensation and ultra-strong acid catalyzed method,and applications of CTFs in photo-and electro-catalysis.Finally we offer some insights into the future development progress of CTFs materials for catalytic applications.展开更多
Covalent triazine framework nanosheets (CTF NSs),an emerging class of two-dimensional nanomaterials,have received great attention due to their abundant active sites,permanent porosity,molecular structural diversity,su...Covalent triazine framework nanosheets (CTF NSs),an emerging class of two-dimensional nanomaterials,have received great attention due to their abundant active sites,permanent porosity,molecular structural diversity,superior chemical/thermal stability,and short charge diffusion path,enabling technological breakthroughs in a myriad of applications. The forefront developments and applications of CTF NSs as photocatalysts and electrochemical electrodes have conferred superior performance and made great impact in the field of energy and advanced catalysis. This forward-looking review aims to summarize the research trends,synthesis,properties of CTF NSs and their CTF counterpart,and highlight their progress in applications with respect to energy storage and conversion devices. Finally,the current challenges and future perspectives for CTF NSs are also presented.展开更多
Converting CO_(2)and water into valuable chemicals like plant do is considered a promising approach to address both environmental and energy issues.Taking inspiration from the structures of natural leaves,we designed ...Converting CO_(2)and water into valuable chemicals like plant do is considered a promising approach to address both environmental and energy issues.Taking inspiration from the structures of natural leaves,we designed and synthesized a novel copper-coordinated covalent triazine framework(CuCTF)supported by silicon nanowire arrays on wafer chip.This marks the first-ever application of such a hybrid material in the photoelectrocatalytic reduction of CO_(2)under mild conditions.The Si@CuCTF6 heterojunction has exhibited exceptional selectivity of 95.6%towards multicarbon products(C_(2+))and apparent quantum efficiency(AQE)of 0.89%for carbon-based products.The active sites of the catalysts are derived from the nitrogen atoms of unique triazine ring structure in the ordered porous framework and the abundant Cu-N coordination sites with bipyridine units.Furthermore,through DFT calculations and operando FTIR spectra analysis,we proposed a comprehensive mechanism for the photoelectrocatalytic CO_(2)reduction,confirming the existence of key intermediate species such as*CO_(2)-,*=C=O,*CHO and*CO-CHO etc.This work not only provides a new way to mimic photosynthesis of plant leaves but also gives a new opportunity to enter this research field in the future.展开更多
基金the financial support by the National Natural Science Foundation of China(Nos.22205124,52172206)Natural Science Foundation of Shandong province(Nos.ZR2021QB070,ZR2023QB110)+2 种基金Basic Research Projects for the Pilot Project of Integrating Science and Education and Industry of Qilu University of Technology(Shandong Academy of Sciences)(Nos.2023PY024,2023PX108)Special Fund for Taishan Scholars Projectthe Development Plan of Youth Innovation Team in Colleges and Universities of Shandong Province。
文摘The high conductivity of electrocatalyst can eliminate the Schottky energy barrier at the interface of heterogeneous phases during an electrocatalytic reaction and accelerate the rapid electron transfer to the catalytic active center.Therefore,the electronic conductivity is a vital parameter for oxygen reduction reaction(ORR).Covalent triazine frameworks(CTFs)have shown great potential application as electrocatalysts in ORR with a merit of the diverse building blocks.However,the intrinsic low conductivity and high impedance of CTFs could be significant setbacks in electrocatalytic application.Herein,CTFs were constructed by introducing F and N co-modification for efficient 2e^(-)ORR.Compared with the pristine CTF,the co-presence of F,N could increase the conductivity obviously by 1000-fold.As a result,F-N-CTF exhibits enhanced catalytic performance of H_(2)O_(2)generation and selectivity towards reaction pathways.This work reveals the importance of conductivity optimization for CTFs and provides guidance for designing high conductivity non-metallic organic semiconductor catalysts for 2e^(-)ORR.
文摘Solar‐driven CO_(2)conversion to precious fossil fuels has been proved to become a potential way to decrease CO_(2)with producing renewable fuels,which mainly relies on photocatalysts with efficient charge separation.In this work,a metal free heterostructure of covalent triazine framework(CTF)and graphite carbon nitride(g‐C_(3)N_(4),abbreviated as CN)is applied in the CO_(2)photoreduction for the first time.Detailed characterization methods such as photoluminescence(PL)and time‐resolved PL(TR‐PL)decay are utilized to reveal the photo‐induced carries separating process on g‐C_(3)N_(4)/CTF(CN/CTF)heterostructure.The introduced CTF demonstrated a great boosting photocatalytic activity for CN,bringing about the transform rates of CO_(2)to CO reaching 151.1μmol/(g·h)with a 30 h stabilization time,while negligible CH_(4)was detected.The optimal CN/CTF heterostructure could more efficiently separate charges with a lower probability of recombination under visible light irradiation,which made the photoreduction efficiency of CO_(2)to CO be 25.5 and 2.5 times higher than that of CTF and CN,respectively.This investigation is expected to offer a new thought for fabricating high‐efficiency photocatalyst without metal in solar‐energy‐driven CO_(2)reduction.
文摘The photocatalytic production of syngas using a noble-metal-free catalytic system is a promising approach for renewable energy and environmental sustainability.In this study,we demonstrate an efficient catalytic system formed by integrating Co single sites,which act as the active sites,in covalent triazine frameworks(CTFs),which act as the photoabsorber,for the photocatalytic production of syngas from CO2 in aqueous solution.The enhanced light absorption of the CTFs,which contain intramolecular heterojunctions,in conjunction with 0.8 mmol L^‒1 of the Co complex enables excellent syngas production with a yield of 3303μmol g‒1(CO:H2=1.4:1)in 10 h,which is about three times greater than that achieved using CTF without a heterojunction.In the photocatalytic reaction,the coordinated single Co centers accept the photogenerated electrons from the CTF,and serve as active sites for CO2 conversion through an adsorption-activation-reaction mechanism.Theoretical calculations further reveal that the intramolecular heterojunctions highly promote photogenerated charge separation,thus boosting photocatalytic syngas production.This work reveals the promising potential of CTFs for single-metal-site-based photocatalysis.
基金Ministry of Trade,Industry&Energy of Korea,Grant/Award Number:RS‐2022‐00155717National Research Foundation of Korea,Grant/Award Numbers:2020H1D3A1A04081472,2022M3J1A1054323。
文摘Carbon super-heterostructures with high nitrogen contents from the covalent hybrid precursors of covalent triazine frameworks(CTFs)and zeolitic imidazolic frameworks(ZIFs)are scarcely explored because of CTF's ordered structure and toxic superacid that dissolves or destabilizes the metal nodes.To solve this problem,herein,we report a straightforward two-step pathway for the covalent hybridization of disordered CTF(d–CTF)–ZIF composites via preincorporation of an imidazole(IM)linker into ordered CTFs,followed by the imidazole-site-specific covalent growth of ZIFs.Direct carbonization of these synthesized d–CTF−IM−ZIF hybrids results in unique hollow carbon super-heterostructures with ultrahigh nitrogen content(>18.6%),high specific surface area(1663m^(2)g^(−1)),and beneficial trace metal(Co/Zn NPs)contents for promoting the redox pseudocapacitance.As proof of concept,the obtained carbon super-heterostructure(Co–Zn–NC_(SNH)–800)is used as a positive electrode in an asymmetric supercapacitor,demonstrating a remarkable energy density of 61Wh kg^(−1)and extraordinary cyclic stability of 97%retention after 30,000 cycles at the cell level.Our presynthetic modifications of CTF and their covalent hybridization with ZIF crystals pave the way toward new design strategies for synthesizing functional porous carbon materials for promising energy applications.
基金the National Natural Science Foundation of China(Nos.21976069,21677062,21507155)。
文摘Porous polymer(pyrrolopyrrole)was successfully prepared via domino-ring-formation reaction.The chemical-physical properties of cyanided covalent triazine frameworks(CTF-CN)were characteriazed by fourier transform infrared spectra(FT-IR),scanning electron microscopy(SEM),nuclear magnetic resonance(NMR),specific surface area analyzer(BET)and thermogravimetric analysis(TGA),respectively.The experimental results of adsorption of chloranil(TCBQ)in aqueous solution indicated that CTF-CN exhibited distinctive adsorption capacity toward TCBQ owing to its large specific surface area.Specifically,the adsorption equilibrium of as-prepared polymer was executed within 5 h and the calculated adsorption capacity was 499.76 mg/g.Furthermore,the adsorption kinetics could be well defined with the linear pseudo-second-order model,which implies that the chemical interaction are relative important in the course of TCBQ removal.Finally,the current studies verify that CTF-CN has unique rigid and nano-porous framework structure,which can be employed for the treatment of a series of harmful aromatic substances.
基金supported by the National Natural Science Foundation of China(Nos.22006131 and 22276171)the Zhejiang Provincial Natural Science Foundation of China(No.LQ20B070010)+1 种基金the China Postdoctoral Science Foundation(Nos.2020T130598 and 2019M662106)the Fund of Zhuhai Science and Technology Bureau,China(No.ZH22017003210025PWC)。
文摘Photocatalysis using the abundant solar energy is an environmentally friendly and efficient way to degrade organic matter.Covalent triazine frameworks(CTFs),a new class of metal-free organic semiconductors responsive to visible light,are promising materials for water treatment.In this study,an original CTF,namely CTF-1,was modified by S-doping to form CTFSx,which were used as metal-free catalysts for degradation of methyl orange(MO)and bisphenol A(BPA).The outcomes demonstrated that the photocatalytic degradation of MO and BPA by CTFSxwas superior to that by CTF-1,with better stability and reusability.Within 6 h,53.2%MO and 84.7%BPA were degraded by CTFS5,and the degradation rate constants were 0.145 h-1and 0.29 h-1,respectively,which were 3.6 and 5.8 times higher than those of CTF-1.Further investigation revealed that enhanced visible light absorption,a reduced degree of free carrier recombination,rapid separation and transfer of photogenerated electrons and holes,and improved·OH oxidation capacity were important factors contributing to the significantly enhanced photocatalytic activity.The S-doping method effectively improved the light absorption performance,electronic structure,and modulation band structure of CTF-1.This work highlights the potential application of low-cost metal-free catalysts driven by visible light for the removal of organic pollutants from wastewater.
文摘In recent years,photocatalysis with efficient,low-cost and stable metal-free catalysts is one of the most promising technologies for non-polluting energy production and resource-economic environment purifying.Benefiting from the molecularly precise backbones,regular and homogeneous porosity,lightelement composition,nitrogen-rich system with unique electronic band structure of two-dimensional(2D)covalent triazine framework(CTF),as well as the huge specific surface area,superior thermal conductivity,excellent carrier mobility and mechanical properties of 2D graphene,CTF/graphene hybrid-based photocatalysts show great application potential in the field of photocatalysis.In this review,the recent development in synthesis of CTF/graphene hybrid-based photocatalysts,and their applications in photocatalytic water splitting for hydrogen production and photocatalytic degradation of pollutants are summarized.Firstly,we briefly describe the molecular structures,physicochemical properties,and synthetic strategies for CTF/graphene hybrid-based photocatalysts including solution mixing method,in-situ polymerization method and sol-gel method.We further assess the impact of different preparation methods on the structure,morphology,and interacting model between CTF and graphene in CTF/graphene hybrids.Following the various preparation process for CTF/graphene hybrid-based photocatalysts,these methods are analyzed and compared regarding their merits and demerits.Secondly,the functions of CTF/graphene hybrid-based photocatalysts obtained from different synthesis approaches that enhance the catalytic activity for photocataLytic hydrogen evolution and photocatalytic degradation of pollutants are discussed from the three aspects of light harvesting,charge separation and transfer,and surface catalysis.Particular focus has been placed on the catalytic mechanisms of CTF/graphene hybridbased photocatalysts for enhanced photocatalytic hydrogen evolution and improved photocatalytic degradation of pollutants.Then the rational manipulation of selection and building units of CTF,connecting bonds between CTF and graphene,dimensions and pore structures of CTF/graphene hybrids in design of CTF/graphene hybrid-based photocatalysts is discussed,aiming to inspire critical thinking about the effective strategies for modification of photocatalysts rather than the development of novel materials.In the end,the challenges and some future trends of CTF/graphene hybrids as advanced photocatalysts are also discussed from three aspects:catalysts design,performance stability and reaction mechanism.The approaches offer potential solutions to address the challenges of largescale production,catalyst activity and stability in the further research and development of new types of metal-free hybrid photocatalysts with high efficiency.
基金supported by the National Natural Science Foundation of China(22409170)the Hunan Provincial Natural Scientific Foundation of China(2024JJ7315)+1 种基金the Scientific Research Fund of Hunan Provincial Education Department(24B0170)the Scientific Research Projects of Hunan University of Arts and Science(24ZZ01).
文摘Controllable fabrication of multi-electroactive sites and morphology-ordered carbon electrodes with excellent capacity and alleviating self-discharge behavior for aqueous redox-enhanced supercapacitors(SCRE)is highly desirable but still challenging.Herein,the N/P/S-rich carbon nanosheets with ultrathin thickness(2–3 nm)and hierarchical porous structure are successfully prepared via phytic acid-driven interfacial phosphorization strategy using S-bridged covalent triazine framework nanosheets(CTFS)as precursor,which are synthesized through a eutectic molten salt-induced ionothermal polymerization.The carbon electrode with adequate N/P/S active sites is pioneeringly introduced in SCRE,clarifying that the coupling hierarchical porous structure and multi-electroactive sites can effectively enhance the interface interaction between carbon electrodes and redox electrolytes via the ex-situ characterizations and theoretical calculations.Consequently,the resultant N/P/S-rich carbon nanosheet(PCTFSC)enables SCRE in KI-doped H2SO4 electrolyte to achieve state-of-the-art specific capacity(1586 mA·h·g^(-1) at 1 A·g^(-1))with 60%of capacity retention at 16 A·g^(-1) and ultra-high energy density of 816 Wh·kg–1,exceeding the reported aqueous supercapacitors thus far.Moreover,the PCTFS based SCRE also exhibits a low self-discharge rate(holding 50%of open circuit potential after 15 h).This study provides new insights to design and regulate advanced carbon materials from the atom level and nano-morphology toward high performance SCRE.
基金Zhejiang Provincial Key Research and Development Program,Grant/Award Numbers:2024C01204,2024C01240(SD2)National Natural Science Foundation of China,Grant/Award Numbers:52203103,52327802,32101465+1 种基金Innovation Research Project for Youth Scholar of School of Environment and Natural Resources,Zhejiang University of Science and Technology,Grant/Award Number:HZQY202403Shenzhen Postdoctoral Research Funding,Grant/Award Number:23301004。
文摘Covalent triazine frameworks(CTFs),known as highly conjugated layered solids,have garnered significant interest due to their distinctive structural and property characteristics.However,the exfoliation of CTF solids towards nanoCTFs in high yields is currently inadequate and inefficient,limiting their utility.This study presents the design and synthesis of CTFs containing non-crystalline regions and their random stacks using a methyl-containing nitrile monomer.Incorporating in-plane methyl groups enhances the polarity of CTFs and disrupts layered interactions,facilitating smooth exfoliation under competing solvent-layer interactions and producing nanocolloids in dilute dispersions.Furthermore,CTFs can rapidly disperse in DMF at a high concentration,enabling the formation of CTF organogel for the first time.Additionally,the designed CTF nanocolloids allow for the first simple physical modification of carbon nanotubes.The assembly,associated with conjugated features,enables the fabrication of CTF/carbon nanotube organogel.
基金supported by the National Natural Science Foundation of China(Nos.22261132512,22235001,22175020,and 22131005)Guizhou Provincial Key Laboratory Platform Project(No.ZSYS[2025]008)+1 种基金Talent Program of Guizhou University(No.[2024]11)Xiaomi Young Scholar Program,and University of Science and Technology Beijing.
文摘Robust covalent organic frameworks(COFs)with abundant redox-active sites have attracted intense attention for organic cathode materials due to the ordered structure and excellent stability.Herein,a two-dimensional(2D)crystalline copper-porphyrin covalent triazine framework(CuBCPP-CTF)was synthesized via polycondensation of 5,15-bis(4-cyanophenyl)porphyrin(H_(2)BCPP)and followed by post-copperization.The integration of copper-porphyrin moieties and triazine linkages provides two kinds of functional sites for outstanding Li+and PF6−ions storage.Electrochemical studies reveal a high discharge capacity of 232 mAh·g^(−1)at 200 mA·g^(−1)and high mid-point voltage(2.77 V vs.Li^(+)/Li),corresponding to an outstanding energy density of 601 Wh·kg^(−1).Density functional theory calculations and ex-situ characterizations disclose the intrinsic bipolar redox mechanism of metalloporphyrin for both PF6−and Li^(+)accommodation and p-type triazine units for PF_(6)^(−)storage.
基金the National Key Research and Development Program of China(2018YFA0208600,2018YFA0704502)NSFC(21871263,22071245,22033008)+1 种基金Strategic Priority Research Program of the Chinese Academy of Sciences(XDB20000000)the Youth Innovation Promotion Association,CAS(Y201850)。
文摘Electroreduction of CO_(2)into chemicals is of great importance in the global carbon balance.Although noble-metal based catalysts and single-atom catalysts(SACs)are known to be active for CO_(2)electroreduction reaction(CO_(2)RR),the high cost of noble-metal and the lack of effective synthesis approaches to prepare SACs have tremendously hindered the application.Non-metal doped carbon materials have attracted great interest because of their reasonable cost,chemical stability and excellent electrical conductivity.Nevertheless,the design and fabrication of highly efficient non-metal doped carbon electrocatalysts for CO_(2)RR to meet industry demands still remains a big challenge.Herein,triphenylphosphine@covalent triazine frameworks(CTFs)composites were employed as precursors to fabricate N,P dual-doped porous carbon catalysts PCTF-X-Y(X represents the carbonization temperature,and Y represents the mass ratio of CTF to triphenylphosphine)for CO_(2)RR.Due to the high specific surface areas and synergistic effect between N and P,the obtained PCTF-1000-5 exhibited high selectivity for CO production up to 84.3%at–0.7 V versus the reversible hydrogen electrode(vs.RHE)and long-term durability over 16 h,which are better than the reported N,P dual-doped carbon catalysts in aqueous media.This work provides a new way to design and fabricate non-metal catalysts for electrocatalysis.
基金supported by the National Natural Science Foundation of China (21975086, 52203259)the International S&T Cooperation Program of China (22161142005, 2018YFE0117300)。
文摘Crystallization is an unsolved challenge in the chemistry of covalent triazine frameworks(CTFs) due to the poorly controlled simultaneous polymerization and crystallization processes. Herein, the synthesis of crystalline CTFs via the introduction of aliphatic amine as a dynamic modulator is reported. By optimizing the amount of aliphatic amine, the crystallization process can be controlled in an open system, resulting in the synthesis of crystalline CTFs. These crystalline CTFs exhibit much better photocatalytic hydrogen evolution performance, with highly ordered CTF-1-C3 demonstrating superior performance(10 mmol g^(-1)h^(-1)) compared with most reported CTF-1. This approach also allows for the preparation of various crystalline CTFs.
基金supported by the Ministry of Science and Technology of China(2012CB933403)the National Natural Science Foundation of China(51425302 and 51302045)the Chinese Academy of Sciences
文摘Single cobalt atom is promising non-precious metal catalyst instead of Pt in the oxygen reduction reaction(ORR).However,it is still a great challenge to develop a costeffective,ultrastable and efficent single-atom cobalt catalyst for ORR,requiring efficient fabrication strategies and robust support to stabilize the single cobalt atom.Here,we prepared a highly active and stable atomically isolated cobalt catalyst via covalent triazine framework(CTF)support with Ketjen Black(KB)hybridization in scale.The prepared single Co catalyst(Co-CTF/KB)possesses high metal loading over 4 wt%and shows superior ORR performance with a half-wave potential(E1/2)of 0.830 V and a limiting current density of 6.14 mA cm-2 as well as high tolerance of methanol in an alkaline medium,which outperforms commercial Pt/C and most non-precious-metal catalysts reported to date.Benefiting from strong stabilization of Co atoms on CTF,Co-CTF/KB shows outstanding stability with only 5 mV negative shifts after 10,000 cycles.Moreover,it also displays high catalytic activity for oxygen evolution reaction(OER),suggesting it is an efficient ORR/OER bifunctional catalyst.The present work provides a facile strategy for preparing single-atom catalysts in bulk quantity and contributes to development of catalysts for electrochemical conversion and storage devices.
基金supported by the National Natural Science Foundation of China(22078241)the Fundamental Research Funds for the Central Universitiesthe Haihe Laboratory of Sustainable Chemical Transformations。
文摘A highly conjugated network of covalent triazine frameworks(CTFs)on the one hand promotes light-harvesting,but on the other hand,also results in high carrier recombination which eventually limits their photocatalytic hydrogen evolution reaction(HER)rates.Thus,strategies to favorably tune the electronic configuration of CTFs for efficient photocatalytic HERs need to be developed,but still remain challenging.Herein,a simple in-situ defect strategy involving element doping is developed for the first time to introduce a heteroatom including S and Se into CTF-1 via the condensation of aldehydes with the mixture of the terephthalimidamide and the S-or Se-substituted terephthalimidamide under mild conditions.The doping content(X)is varied,resulting in a series of S-and Se-doped CTFs,named CTFS-1-X and CTFSe-1-X,respectively.Interestingly,for the S-doped CTFs,CTFS-1-10 shows the most excellent HER rate(4,992.3μmol g^(-1)h^(-1))from water splitting,while for the Se-doped ones,CTFSe-1-10 exhibits a photocatalytic HER rate of 5,792.8μmol g^(-1)h^(-1),both of which far surpass undoped CTFs(693.3μmol g^(-1)h^(-1)).In-depth studies indicate that the introduction of S or Se atoms into CTFs could extend the light absorption and promote photo-generated electron-hole pairs migration.Meanwhile,S-or Se-doping could create heterogeneous electronic configuration in CTFs,which can help to suppress carrier recombination.
基金support from the National Key Research and Development Program of China(nos.2018YFA0208600 and 2018YFA0704502)NSFC(nos.22071245,21671188,21871263,and 21520102001)+2 种基金Key Research Program of Frontier Science,CAS(no.QYZDJ-SSW-SLH045)Strategic Priority Research Program of the Chinese Academy of Sciences(no.XDB20000000)and Youth Innovation Promotion Association,CAS(no.Y201850).
文摘Tandem catalytic reactions have attracted extensive interest because of their ability to reduce reaction steps,energy consumption,and waste.However,the construction of highly efficient tandem catalytic systems is still a significant challenge due to the problematic integration of multiple active sites in one reaction system and the incompatibility of different reaction conditions.Although metal nanoparticles(MNPs)supported on porous framework materials have shown excellent catalytic performances in various reactions,their cooperative catalysis for tandem reactions is rarely reported.
基金K.A.I.Z.acknowledges the Max Planck Society for financial support.C.A.is a recipient of a fellowship through funding of the Excellence Initiative(DFG/GSC 266)of the Graduate School of Excellence“MAINZ”(Materials Science in Mainz).
文摘Covalent triazine frameworks(CTFs)have been recently employed for visible light-driven photocatalysis due to their unique optical and electronic properties.However,the usually highly hydrophobic nature of CTFs,which originates from their overall aromatic backbone,leads to limitations of CTFs for applications in aqueous media.In this study,we aim to extend the range of the application media of CTFs and design hybrid material of a CTF and mesoporous silica(SBA-15)for efficient photocatalysis in aqueous medium.A thiophene-containing CTF was directly synthesized in mesopores of SBA-15.Due to the high surface area and the added hydrophilic properties by silica,the hybrid material demonstrated excellent adsorption of organic molecules in water.This leads not only to high photocatalytic performance of the hybrid material for the degradation of organic dyes in water,but also for efficient photocatalysis in solvent-free and solid state.Furthermore,the reusability,stability and easy recovery of the hybrid material offers promising metal-free heterogeneous photocatalyst for broader applications in different reaction media.
基金supported by the National Natural Science Foundation of China(21875078 and 21975146)。
文摘Porous organic polymers(POPs)are an emerging class of porous materials,having many promising applications in a variety of areas.Among them,covalent triazine frameworks(CTFs)featuring conjugated and porous structures can be well applied in optoelectronics.To achieve high optoelectronic performance,usually the design and synthesis of CTFs based on appropriate building blocks is critical.Here we report the synthesis of two fluorescent CTFs based on typical fluorescent building blocks,in which CTF-Py constructed from a pyrene(Py)building block was reported for the first time,showing prospective applications in the sensing of nitroaromatics with high sensitivity,and photocatalytic water splitting and carbon dioxide reduction with high performance in comparison with other porous organic materials.
基金the National Natural Science Foundation of China(Nos.42167068 and 22269020)Gansu Province Higher Education Industry Support Plan Project(No.2023CYZC-68)the Hubei Province Outstanding Youth Fund Project(No.2023AFA108).
文摘Covalent triazine frameworks(CTFs)are a class of unique two-dimensional nitrogen-rich triazine framework with adjustable chemical and electronic structures,rich porosity,good stability and excellent semiconductivity,which enable great various applications in efficient gas/molecular adsorption and separation,energy storage and conversion,especially photo-and electrocatalysis.Different synthesis strategies strongly affect the morphology of CTFs and play an important role in their structure and properties.In this concept,we provide a comprehensive and systematic review of the synthesis methods such as ionothermal synthesis,phosphorus pentoxide catalytic method,polycondensation and ultra-strong acid catalyzed method,and applications of CTFs in photo-and electro-catalysis.Finally we offer some insights into the future development progress of CTFs materials for catalytic applications.
文摘Covalent triazine framework nanosheets (CTF NSs),an emerging class of two-dimensional nanomaterials,have received great attention due to their abundant active sites,permanent porosity,molecular structural diversity,superior chemical/thermal stability,and short charge diffusion path,enabling technological breakthroughs in a myriad of applications. The forefront developments and applications of CTF NSs as photocatalysts and electrochemical electrodes have conferred superior performance and made great impact in the field of energy and advanced catalysis. This forward-looking review aims to summarize the research trends,synthesis,properties of CTF NSs and their CTF counterpart,and highlight their progress in applications with respect to energy storage and conversion devices. Finally,the current challenges and future perspectives for CTF NSs are also presented.
基金supported by Natural Science Foundation of Gansu Province(23JRRA745)the Fundamental Research Funds for the Central Universities(lzujbky2021-sp55).
文摘Converting CO_(2)and water into valuable chemicals like plant do is considered a promising approach to address both environmental and energy issues.Taking inspiration from the structures of natural leaves,we designed and synthesized a novel copper-coordinated covalent triazine framework(CuCTF)supported by silicon nanowire arrays on wafer chip.This marks the first-ever application of such a hybrid material in the photoelectrocatalytic reduction of CO_(2)under mild conditions.The Si@CuCTF6 heterojunction has exhibited exceptional selectivity of 95.6%towards multicarbon products(C_(2+))and apparent quantum efficiency(AQE)of 0.89%for carbon-based products.The active sites of the catalysts are derived from the nitrogen atoms of unique triazine ring structure in the ordered porous framework and the abundant Cu-N coordination sites with bipyridine units.Furthermore,through DFT calculations and operando FTIR spectra analysis,we proposed a comprehensive mechanism for the photoelectrocatalytic CO_(2)reduction,confirming the existence of key intermediate species such as*CO_(2)-,*=C=O,*CHO and*CO-CHO etc.This work not only provides a new way to mimic photosynthesis of plant leaves but also gives a new opportunity to enter this research field in the future.
