Vacancy engineering is a useful methodology in the development of catalysts and electrode materials.Herein,we report the introduction of Se-vacancy pairs in heteroatom-doped(N,B,and F)CoSe/Mo_(2)CT_(x) MXene(NBF-CoSe/...Vacancy engineering is a useful methodology in the development of catalysts and electrode materials.Herein,we report the introduction of Se-vacancy pairs in heteroatom-doped(N,B,and F)CoSe/Mo_(2)CT_(x) MXene(NBF-CoSe/Mo_(2)CT_(x))to enhance the hydrogen evolution reaction(HER)and supercapacitor activities via an ionic liquid-mediated method.Se vacancy pairs and heteroatom doping enable the reallocation of local electron states and add active sites,improving the electrochemical activity of NBF-CoSe/Mo_(2)CT_(x) with high HER activities over a broad range of pH.At a current density of 10 mA cm^(-2),overvoltages of 70 and 81 mV are respectively produced in 0.5 M H_(2)SO_(4)and 1 M KOH.The optimal structure also exhibits outstanding electrochemical performance in an asymmetric supercapacitor with an energy density of 34.2 Wh kg^(-1)at a power density of 15989.6Wkg^(-1).This study opens new avenues for the introduction of Se vacancies and heteroatom doping to improve the application performance.展开更多
Transition metal sulfides have been regarded as promising anode materials for sodium-ion batteries(SIB).However,they face the challenges of poor electronic conductivity and large volume change,which result in capacity...Transition metal sulfides have been regarded as promising anode materials for sodium-ion batteries(SIB).However,they face the challenges of poor electronic conductivity and large volume change,which result in capacity fade and low rate capability.In this work,a composite containing ultrasmall CoS(~7 nm)nanoparticles embedded in heteroatom(N,S,and O)-doped carbon was synthesized by an efficient one-step sulfidation process using a Co(Salen)precursor.The ultrasmall CoS nanoparticles are beneficial for mechanical stability and shortening Na-ions diffusion pathways.Furthermore,the N,S,and O-doped defect-rich carbon provides a robust and highly conductive framework enriched with active sites for sodium storage as well as mitigates volume expansion and polysulfide shuttle.As anode for SIB,CoS@HDC exhibits a high initial capacity of 906 mA h g^(-1)at 100 mA g^(-1)and a stable long-term cycling life with over 1000 cycles at 500 mA g^(-1),showing a reversible capacity of 330 mA h g^(-1).Meanwhile,the CoS@HDC anode is proven to maintain its structural integrity and compositional reversibility during cycling.Furthermore,Na-ion full batteries based on the CoS@HDC anode and Na_(3)V_(2)(PO_(4))_(3)cathode demonstrate a stable cycling behavior with a reversible specific capacity of~200 m A h g^(-1)at least for 100 cycles.Moreover,advanced synchrotron operando X-ray diffraction,ex-situ X-ray absorption spectroscopy,and comprehensive electrochemical tests reveal the structural transformation and the Co coordination chemistry evolution of the CoS@HDC during cycling,providing fundamental insights into the sodium storage mechanism.展开更多
Carbonaceous material has attracted much attention in the application of sodium-ion batteries(SIBs)anode.However,sluggish reaction kinetics and structure stability impede the application.Therefore,a stacked layered su...Carbonaceous material has attracted much attention in the application of sodium-ion batteries(SIBs)anode.However,sluggish reaction kinetics and structure stability impede the application.Therefore,a stacked layered sulfur-carbon complex with long-chain C–S_(x)–C bond(M-SC-S)is prepared.The layered structure ensures structural stability,and long-chain C–S_(x)–C bond expanding interlayer spacing boosts facile Na+diffusion.When assembled into cells,a high-quality solid-electrolyte interphase film would be formed due to a good match between the M-SC-S electrode and ether electrolyte.Moreover,an electrochemical activation process would happen between the Cu current collector and proper S-doped electrode material to in-situ form Cu_(2)S.The formation of Cu_(2)S in active material can not only provide more active sites for sodium storage and enhance pseudo-capacitance,but also reinforce the electrode/current collector interface and decrease the interfacial transfer resistance for rapid Na+kinetics.The synergistic effect of structure design and interface engineering optimizes the sodium storage system.Thus,the M-SC-S electrode delivers an excellent cyclic performance(321.6 mAh g^(−1)after 1000 cycles at 2 A g^(−1)with a capacity retention rate of 97.4%)and good rate capability(282.8 mAh g^(−1)after 4000 cycles even at a high current density of 10 A g^(−1)).The full cell also has an impressive cyclic performance(151.4 mAh g^(−1)after 500 cycles at 0.5 A g^(−1)).展开更多
Two-dimensional(2D)carbon materials with ultrathin thickness,large lateral size,large surface area,accessible active sites and unique physical-chemical properties have been proven to be attractive electrode materials ...Two-dimensional(2D)carbon materials with ultrathin thickness,large lateral size,large surface area,accessible active sites and unique physical-chemical properties have been proven to be attractive electrode materials or catalysts for high-efficient energy storage and conversion materials.However,the conventional synthesis method for 2D carbon materials heavily depends on fossil-based feedstocks and goes through harsh conditions(e.g.,chemical vapor deposition),which are unsustainable and costly.Besides,the top-down method needs to use massive strong acids/oxidants,which is environmentallyunfriendly.Therefore,it is necessary to commit to seek green,sustainable and cost-effective approach for the synthesis of 2D carbon materials.As of now,biomass or biological molecules as carbon-rich resources have been viewed as a promising candidate for the 2D carbon material preparation owing to its abundance,renewability,nontoxicity and low-cost.Especially for nucleobases,as an emerging molecule have been shown great advantages for the construction of 2D materials guided by its multiple hydrogen-bonding interaction.Recently,our group have proposed a rather innovative strategy to produce 2D carbon materials by carbonization of nucleobases which has relatively high electrode potentials.These nucleobases can form planar network structure through hydrogen bonding interaction.Such hydrogenbonding can be stable at relatively high temperature,which confines C-C or C-N polymerization in a 2D plane.As a result,direct carbonization of nucleobases enables the formation of 2D carbon with highly sp2-conjugated and feature of heteroatom doping.This review systematically summarizes the recent development of the strategies to synthesize 2D sustainable carbon materials from biomass and biological molecules.The corresponding electrochemical applications such as lithium ion batteries,supercapacitors and fuel cell are selectively presented.At the end,the summary and future perspectives in this important field are provided to inspire further exploration.展开更多
The exploration of active and robust electrocatalysts for both the oxygen reduction reaction(ORR)and oxygen evolution reaction(OER)is the bottleneck to realize the commercialization of rechargeable metal-air batteries...The exploration of active and robust electrocatalysts for both the oxygen reduction reaction(ORR)and oxygen evolution reaction(OER)is the bottleneck to realize the commercialization of rechargeable metal-air batteries and regenerative fuel cells.Here we report facile synthesis of three-dimensional(3 D)carbon nanotube(CNT)/carbon composites using earth-abundant coal as the carbon source,hydrogen reductant and heteroatom dopant to grow CNTs.The prepared composite featuring 3 D structural merits and multiple active sites can efficiently catalyze both ORR and OER,affording high activity,fast kinetics,and long-term stability.With the additional incorporation of manganese,the developed catalyst afforded a potential difference of 0.80 V between ORR at the half wave potential and OER at a current density of 10 mA cm^(-2).The optimized sample has presented excellent OER performance within a constructed solar-powered water splitting system with continuously generating oxygen bubbles at anode.Notably,it can be further used as a durable air-electrode catalyst in constructed Zn-air battery,delivering an initial discharge/charge voltage gap of 0.73 V,a remained voltaic efficiency of 61.2%after 160 cycles and capability to power LED light for at least 80 h.This study provides an efficient approach for converting traditional energy resource i.e.coal to value-added alternative oxygen electrocatalysts in renewable energy conversion systems.展开更多
Potassium-selenium(K-Se)batteries have attracted more and more attention because of their high theoretical specific capacity and natural abundance of K resources.However,dissolution of polyselenides,large volume expan...Potassium-selenium(K-Se)batteries have attracted more and more attention because of their high theoretical specific capacity and natural abundance of K resources.However,dissolution of polyselenides,large volume expansion during cycling and low utilization of Se remain great challenges,leading to poor rate capability and cycle life.Herein,N/O dual-doped carbon nanofibers with interconnected micro/mesopores(MMCFs)are designed as hosts to manipulate Se molecular configuration for advanced flexible K-Se batteries.The micropores play a role in confining small Se molecule(Se_(2–3)),which could inhibit the formation of polyselenides and work as physical barrier to stabilize the cycle performance.While the mesopores can confine long-chain Se(Se_(4–7)),promising sufficient Se loading and contributing to higher discharge voltage of the whole Se@MMCFs composite.The N/O co-doping and the 3D interpenetrating nanostructure improve electrical conductivity and keep the structure integrity after cycling.The obtained Se_(2–3)/Se_(4–7)@MMCFs electrode exhibits an unprecedented cycle life(395 mA h g^(−1) at 1 A g^(−1) after 2000 cycles)and high specific energy density(400 Wh kg^(−1),nearly twice the specific energy density of the Se_(2–3)@MMCFs).This study offers a rational design for the realization of a high energy density and long cycle life chalcogen cathode for energy storage.展开更多
Herein,the merits of heterojunction,CeO_(2),and W are employed to design and prepare the PtCoW@CeO_(2)heterojunction catalyst,which can accelerate water dissociation and improve the desorption of OHad,displaying effic...Herein,the merits of heterojunction,CeO_(2),and W are employed to design and prepare the PtCoW@CeO_(2)heterojunction catalyst,which can accelerate water dissociation and improve the desorption of OHad,displaying efficient hydrogen evolution reaction(HER)performance in pH-universal conditions.Density functional theory calculation results reveal that the electronic structure of Pt is regulated by CeO_(2)and W,which tunes the Pt-Hadbond strength to boost HER intrinsic activity.Consequently,electrochemical results display that it has low potentials of-26,-25,and-23 mV at-10 mA cm^(-2)in alkaline,neutral,and acidic solutions,respectively,and it can stably cycle for 50,000 cycles.Thus,this work provides the guidance for developing high-performance Pt-based catalysts in pH-universal environments.展开更多
Nitrogen-doped carbon loaded single-atom catalysts(SACs)are promising candidates for electrocatalytic conversion of CO_(2)into high-valuable chemicals,and the modification of catalysts by heteroatom-doping strategy is...Nitrogen-doped carbon loaded single-atom catalysts(SACs)are promising candidates for electrocatalytic conversion of CO_(2)into high-valuable chemicals,and the modification of catalysts by heteroatom-doping strategy is an effective approach to enhance the CO_(2)reduction performance.However,the large difference exists in atomic radius between nitrogen atoms and the doped heteroatoms may lead to the poor stability of active sites.In this study,we have synthesized a Ni single atom catalyst with S doping at the secondshell on the ultrathin carbon nanosheets support(Ni-N_(4)-SC)by solid-phase pyrolysis.The S atom in the second-shell contributes to the higher efficiency of CO_(2)conversion at lower potentials while the Ni-N_(4)-SC can be more stable.The experimental results and theoretical calculations indicate that the S atom in second-shell breaks the uniform charge distribution and reduces the free energy of hydrogenation,which can increase the adsorption of CO_(2),accelerate charge transfer,and reduce the reaction energy barrier.This work reveals the close relationship between the second-shell and the electrocatalytic activity of single atom sites,which also provides a new perspective to design efficient single atom catalysts.展开更多
Carbyne-enriched nanomaterials are of current interest in nanotechnology-related applications.The properties of these nanomaterials greatly depend on their production process.In particular,structural self-organization...Carbyne-enriched nanomaterials are of current interest in nanotechnology-related applications.The properties of these nanomaterials greatly depend on their production process.In particular,structural self-organization and auto-synchronization of nanostructures are typical phenomena observed during the growth and heteroatom-doping of carbyne-enriched nanostructured metamaterials by the ion-assisted pulse-plasma deposition method.Accordingly,fine tuning of these processes may be seen as the key step to the predictive designing of carbyneenriched nano-matrices with improved properties.In particular,we propose an innovative concept,connected with application of the vibrational-acoustic effects and based on universal Cymatics mechanisms.These effects are used to induce vibration-assisted self-organized wave patterns together with the simultaneous manipulation of their properties through an electric field.Interaction between the inhomogeneous electric field distribution generated on the vibrating layer and the plasma ions serves as the additional energizing factor controlling the local pattern formation and self-organization of the nano-structures.展开更多
Metal-free carbon-based catalysts exhibit diverse electrocatalytic performances in CO_(2) reduction reaction(CO_(2)RR),but the attributions and contributions of active sites are still confusing to date.Herein,the hier...Metal-free carbon-based catalysts exhibit diverse electrocatalytic performances in CO_(2) reduction reaction(CO_(2)RR),but the attributions and contributions of active sites are still confusing to date.Herein,the hierarchical carbon nanocages(hCNC)doped with different heteroatoms(B,N,P,S)are prepared to examine the impact of dopants on the competitive CO_(2)RR and hydrogen evolution reaction(HER).The hCNC and P-doped hCNC show little CO_(2)RR activity,B-and S-doped hCNC show weak CO_(2)RR activity,while N-doped hCNC presents high CO_(2)RR activity.The CO Faradaic efficiency(FECO)of N-containing hCNC increases almost linearly with increasing the N content,even with the co-existing B or P.S and SN-doped hCNC more facilitate the HER.16 doping configurations are constructed,and up to 53 sites are examined CO_(2) H2O H2 CO*H*COOH*CO for the electrochemical activities with a constant potential modelling method.The pyridinic-N(N^(*))is the best active site for CO_(2)RR to CO,while CBO_(2)H_(2)-1(αC^(*)),CBO_(2)H_(2)-2(γC^(*)),NO-1(βC^(*)),PO_(2)H-3(αC^(*))and SO_(3)H-3(δC^(*))are active for HER.The optimized FECO achieves 83.6%for N-doped hCNC with 9.54 at.%nitrogen,and S-doped hCNC reaches ca.30 mA·cm^(-2) current density for HER.This study unveils the structure-performance correlation of heteroatom-doped hCNC,which is conducive to the rational design of advanced metal-free carbon-based catalysts.展开更多
For electric double layer supercapacitors,carbon materials originating from the purely physical energystorage mechanism limit the improvement in the capabilities of charge storage.To solve this problem,doping heteroat...For electric double layer supercapacitors,carbon materials originating from the purely physical energystorage mechanism limit the improvement in the capabilities of charge storage.To solve this problem,doping heteroatoms into carbon skeleton is a promising&charming strategy for enhancing electrochemical performance by providing the extra pseudocapacitance.However,the self-discharge behavior of such heteroatom-doped supercapacitors has been a challenging issue for a long time.Here,the porous carbon nanosheets with a tunable total content of heteroatoms are chosen as a demo to systemically decouple the correlation between the total content of heteroatoms and the specific capacitance as well as the self-discharge behavior.The capacitance changes in a range of 164–331 F g^(-1)@1 A g^(-1)with the increased total contents of doped heteroatom,strongly dependent on and sensitive to the total content of heteroatoms.The voltage retention rate and capacitance retention rate for the porous carbon nanosheets with a tunable total content of heteroatoms completely present a quick decline tendency as the increase in the content of heteroatoms,changing from 58%to 34%and 74%to 39%,respectively,indicative of a linear negative relationship.More importantly,the self-discharge mechanisms are elaborately explored and follow the combination of activation-and diffusion-controlled Faradic reactions.This work illustrates the diverse impacts of the doped heteroatoms on the electrochemical performance of supercapacitors,covering specific capacitance and self-discharge behavior,and highlights the importance of balancing the contents of doped heteroatoms in energy storage fields.展开更多
Boron had been introduced into the structure of carbon material(BC), which was used as the support of Pd catalyst for hydrogenation of 4-carboxybenzaldehyde(4-CBA). The physical properties and chemical composition of ...Boron had been introduced into the structure of carbon material(BC), which was used as the support of Pd catalyst for hydrogenation of 4-carboxybenzaldehyde(4-CBA). The physical properties and chemical composition of the support and corresponding catalyst were characterized by N2 adsorption–desorption,Raman spectroscopy, inductively coupled plasma optical emission spectroscopy(ICP-OES), element analysis(EA), high-resolution transmission electron microscopy(HRTEM), CO-pulse chemisorption and X-ray photoelectron spectroscopy(XPS). The results demonstrate that Pd/BC catalyst exhibits a superior activity and good stability due to the more uniform dispersion of Pd nanoparticles, the presence of mesoporous structure and the enhanced interaction between Pd nanoparticles and the support, compared to carbon and N-doped carbon supported Pd catalysts(Pd/C and Pd/NC, respectively).展开更多
Hydrogen production from water electrolysis using renewable electricity is a highly promising route to solve the energy crisis of human society. The tetragonal 3d-transition metal selenide with metallic feature has be...Hydrogen production from water electrolysis using renewable electricity is a highly promising route to solve the energy crisis of human society. The tetragonal 3d-transition metal selenide with metallic feature has been discovered to efficiently catalyze the hydrogen evolution electrocatalysis;however, its performance is still unsatisfactory and further improvement is necessary. Herein, the hydrogen evolution reaction of the functional tetragonal 3d-transition metal selenide with the heteroatom-dopant as well as cationic vacancy is fully investigated by means of density functional theory calculations. Our results identify 53 promising candidates endowed with good activity due to the absolute free energy of hydrogen adsorption |ΔGH| ≤ 0.30 eV wherein 15 candidates with |ΔG_H| ≤ 0.09 eV possess compelling performance in comparison with the benchmark Pt material. Interestingly, the functional CuSe systems account for 29out of 53 candidates, being high attractive for experimental synthesis. According to the analysis of electronic structure, the enhanced performance stems from the upshift of the sp orbitals, which benefits for the improved affinity toward hydrogen capture. This work provides new direction and guidance for the design of novel electrocatalysts.展开更多
The on-purpose direct propane dehydrogenation(PDH) has received extensive attention to meet the everincreasing demand of propylene.In this work,by means of density functional theory(DFT) calculations,we systematically...The on-purpose direct propane dehydrogenation(PDH) has received extensive attention to meet the everincreasing demand of propylene.In this work,by means of density functional theory(DFT) calculations,we systematically studied the intrinsic coordinating effect of Fe single-atom catalysts in PDH.Interestingly,the N and P dual-coordinated single Fe(Fe-N_(3)P-C) significantly outperform the Fe-N_(4-)C site in catalysis and exhibit desired activity and selectivity at industrial PDH temperatures.The mechanistic origin of different performance on Fe-N_(3)P-C and Fe-N_(4-)C has been ascribed to the geometric effect.To be specific,the in-plane configuration of Fe-N_(4) site exhibits low H affinity,which results in poor activity in C-H bond activations.By contrast,the out-of-plane structure of Fe-N_(3)P-C site exhibits moderate H affinity,which not only promote the C-H bond scission but also offer a platform for obtaining appropriate H diffusion rate which ensures the high selectivity of propylene and the regeneration of catalysts.This work demonstrates promising applications of dual-coordinated single-atom catalysts for highly selective propane dehydrogenation.展开更多
The efficiency of carbon dioxide(CO_(2))adsorption in carbonaceous materials is primarily influenced by their microporosity and thermodynamic affinity for CO_(2).However,achieving optimal heteroatom doping and precise...The efficiency of carbon dioxide(CO_(2))adsorption in carbonaceous materials is primarily influenced by their microporosity and thermodynamic affinity for CO_(2).However,achieving optimal heteroatom doping and precise micropore engineering through advanced activation techniques remains a significant challenge.We introduce a solvent-free one-pot method using polythiophene,melamine,and KOH to prepare highly microporous,heteroatom-co-doped carbons(NSC).This approach leverages sulfur from polythiophene,nitrogen from melamine,and the activation agent KOH to enhance CO_(2)capture performance.展开更多
The development of electrolytes with high ionic conductivity and stable electrode–electrolyte interfaces is crucial for the practical realization of solid-state sodium batteries.In this study,the effect of heteroatom...The development of electrolytes with high ionic conductivity and stable electrode–electrolyte interfaces is crucial for the practical realization of solid-state sodium batteries.In this study,the effect of heteroatom doping in a von-Alpen-type Na super ionic conductor(NASICON)was investigated by substituting Zr^(4+)with Mg^(2+),Zn^(2+),and La^(3+)to enhance its material properties and evaluate its potential for solid-state sodium battery applications.Computational chemistry was employed to predict the thermodynamic stability influenced by dopant introduction and the changes in ionic conductivity arising from crystal structure distortion,with the predictions validated by experiments.The optimized Zn^(2+)-doped NASICON(Zn-NZSP0.07)exhibited the highest total ionic conductivity of 2.74×10^(−3)S∙cm^(−1),representing a 4.5-fold increase compared with undoped NASICON(6.00×10−4 S∙cm^(−1)).The material also showed a high relative density of 99.1%,indicating a compact and well-sintered microstructure,as confirmed by a three-point bending test.Furthermore,a high critical current density of 1.4 mA∙cm^(−2)was achieved in symmetric cell testing.Additionally,a Na_(3)V_(2)(PO_(4))_(3)||Zn-NZSP0.07||Na cell delivered an initial capacity of 103.9 mAh∙g^(−1)at 0.1 A∙g^(−1)and retained 73.4%of its capacity after 200 cycles.These results demonstrate that optimal heteroatom doping is crucial for enhancing the performance of NASICON.展开更多
Designing efficient bifunctional catalysts with multi-component composites is essential for the application of zinc-air batteries(ZABs).Herein,a bimetallic phosphides-oxides heterostructures coupled heteroatom-doped c...Designing efficient bifunctional catalysts with multi-component composites is essential for the application of zinc-air batteries(ZABs).Herein,a bimetallic phosphides-oxides heterostructures coupled heteroatom-doped carbon(FeCoP-FeCo_(2)O_(4)@PNPC)was designed by in-situ growth of phosphor-oxide heterostructures on heteroatom-doped carbon materials and employed as bifunctional electrocatalyst for ZABs.The heteroatom-doped carbon substrate with ORR active sites can effectively improve the conductivity and the double transition metal atoms can enhance the catalytic activity.The heterostructure adjusts the d-band center,making the material gain and loss of electrons are at a medium level,which is conducive to the material’s capture of raw materials and the release of products.is beneficial to electron transfer.The dense FeCo_(2)O_(4)nanorods act as a protection layer to improve stability,and the oxide-phosphide heterostructure and synergistic coupling with the heteroatom-doped carbon substrate also contribute to the catalytic activity.The smallΔE of 0.765 V for catalyzing both OER and ORR,high power density of 121.6 mW·cm^(-2)and the extraordinary long-term stability of more than 240 h for liquid state rechargeable ZAB can be realized.The flexible solid-state rechargeable ZAB with FeCoP-FeCo_(2)O_(4)@PNPC also exhibits superior mechanical flexibility and cycling stability.展开更多
In ZnIn_(2)S_(4)-based photocatalytic systems,structural optimization and compositional regulation are crucial for significantly enhancing hydrogen production performance.Atom doping and heterostructure formation have...In ZnIn_(2)S_(4)-based photocatalytic systems,structural optimization and compositional regulation are crucial for significantly enhancing hydrogen production performance.Atom doping and heterostructure formation have been shown to improve solar energy conversion efficiency,thereby boosting photocatalytic performance.However,to date,no one-step synthesis method has been reported that simultaneously constructs hollow heterostructures and introduces heteroatom doping into ZnIn_(2)S_(4)photocatalysts,primarily due to the absence of suitable templates or synthesis strategies.In this study,we propose a novel one-step,coordination-selective strategy based on the hard-soft acid-base theory,using MOF(Ti)as a structure-directing template.By incorporating Ce^(3+),Zn^(2+),In^(3+),and S^(2-),the MOF(Ti)is successfully converted into a hollow MOF(Ce)structure,while Ce-doped ZnIn_(2)S_(4)nanosheets nucleates on its surface.This process yields a highly active 2D/3D hollow core-shell heterojunction photocatalyst,Ce-ZnIn_(2)S_(4)/MOF(Ce).Both theoretical and experimental results demonstrate that this unique structure significantly enhances charge separation and extends the charge carrier's lifetime,leading to markedly improved photocatalytic hydrogen evolution performance.This work offers an innovative and controllable approach for synthesizing MOF-derived hollow core-shell heterojunctions,paving the way for a highly efficient water-splitting system.展开更多
Developing efficient and cost-effective electrode materials is of essential significance to advance various energy storage technologies,among which flexible supercapacitors hold great promise to meet the growing popul...Developing efficient and cost-effective electrode materials is of essential significance to advance various energy storage technologies,among which flexible supercapacitors hold great promise to meet the growing popularity of wearable electronics.Herein,we report a homologous strategy to parallelly synthesize phosphorus-doped ZnCo_(2)O_(4)(P-ZnCo_(2)O_(4)@NCC)and nitrogen-doped carbon(NC@NCC)both derived from ZnCo-metal-organic frameworks(MOFs)precursors in-situ grown on dopamine-modified carbon cloth(NCC)as conductive substrates.Impressively,the as-obtained P-ZnCo_(2)O_(4)@NCC can achieve a high specific capacitance of 2702.2 mF∙cm^(−2)at 1 mA∙cm^(−2)with the capacitance retention rate exceeding 70.6%at 10 mA∙cm^(−2),demonstrating the outstanding rate capability.Moreover,flexible solid-state hybrid supercapacitors,using P-ZnCo_(2)O_(4)@NCC as positive electrode and NC@NCC as negative electrode,are assembled with poly(vinyl alcohol)(PVA)/KOH as the gel electrolyte,which deliver the energy density of 11.9 mWh∙cm^(−3)when the power density reaches up to 47.3 mW∙cm^(−3).In addition,85.15%of the initial specific capacitance is maintained after 5000 continuous cycles and no obvious capacitance decay is observed under different bending conditions,revealing the excellent cycling stability and flexibility.As a proof-of-concept demonstration,two as-assembled hybrid supercapacitors connected in series can light up a red light-emitting diode(LED)under the bending angle of 180°,heralding the feasibility for broad practical applications.展开更多
Heteroatom doping, precise composition control and rational morphology design are efficient strategies for producing novel nanocatalysts for the oxygen reduction reaction （ORR） in fuel cells. Herein, a cost-effectiv...Heteroatom doping, precise composition control and rational morphology design are efficient strategies for producing novel nanocatalysts for the oxygen reduction reaction （ORR） in fuel cells. Herein, a cost-effective approach to synthesize nitrogen- and sulfur-codoped carbon nanowire aerogels using a hard templating method is proposed. The aerogels prepared using a combination of hydrothermal treatment and carbonization exhibit good catalytic activity for the ORR in alkaline solution. At the optimal annealing temperature and mass ratio between the nitrogen and sulfur precursors, the resultant aerogels show comparable electrocatalytic activity to that of a commercial Pt/C catalyst for the ORR. Importantly, the optimized catalyst shows much better long-term stability and satisfactory tolerance for the methanol crossover effect. These codoped aerogels are expected to have potential applications in fuel cells.展开更多
基金supported by the National Natural Science Foundation of China(21905069)the Shenzhen Science and Technology Innovation Committee(JCYJ20180507183907224 and KQTD20170809110344233)the Economic,Trade and Information Commission of Shenzhen Municipality through the Graphene Manufacture Innovation Center(201901161514)。
文摘Vacancy engineering is a useful methodology in the development of catalysts and electrode materials.Herein,we report the introduction of Se-vacancy pairs in heteroatom-doped(N,B,and F)CoSe/Mo_(2)CT_(x) MXene(NBF-CoSe/Mo_(2)CT_(x))to enhance the hydrogen evolution reaction(HER)and supercapacitor activities via an ionic liquid-mediated method.Se vacancy pairs and heteroatom doping enable the reallocation of local electron states and add active sites,improving the electrochemical activity of NBF-CoSe/Mo_(2)CT_(x) with high HER activities over a broad range of pH.At a current density of 10 mA cm^(-2),overvoltages of 70 and 81 mV are respectively produced in 0.5 M H_(2)SO_(4)and 1 M KOH.The optimal structure also exhibits outstanding electrochemical performance in an asymmetric supercapacitor with an energy density of 34.2 Wh kg^(-1)at a power density of 15989.6Wkg^(-1).This study opens new avenues for the introduction of Se vacancies and heteroatom doping to improve the application performance.
基金the financial support from China Scholarship Council(202108080263)Financial support by the Federal Ministry of Education and Research(BMBF)under the project“He Na”(03XP0390C)+1 种基金the German Research Foundation(DFG)under the joint German-Russian DFG project“KIBSS”(448719339)are acknowledgedthe financial support from the Federal Ministry of Education and Research(BMBF)under the project“Ka Si Li”(03XP0254D)in the competence cluster“Excell Batt Mat”。
文摘Transition metal sulfides have been regarded as promising anode materials for sodium-ion batteries(SIB).However,they face the challenges of poor electronic conductivity and large volume change,which result in capacity fade and low rate capability.In this work,a composite containing ultrasmall CoS(~7 nm)nanoparticles embedded in heteroatom(N,S,and O)-doped carbon was synthesized by an efficient one-step sulfidation process using a Co(Salen)precursor.The ultrasmall CoS nanoparticles are beneficial for mechanical stability and shortening Na-ions diffusion pathways.Furthermore,the N,S,and O-doped defect-rich carbon provides a robust and highly conductive framework enriched with active sites for sodium storage as well as mitigates volume expansion and polysulfide shuttle.As anode for SIB,CoS@HDC exhibits a high initial capacity of 906 mA h g^(-1)at 100 mA g^(-1)and a stable long-term cycling life with over 1000 cycles at 500 mA g^(-1),showing a reversible capacity of 330 mA h g^(-1).Meanwhile,the CoS@HDC anode is proven to maintain its structural integrity and compositional reversibility during cycling.Furthermore,Na-ion full batteries based on the CoS@HDC anode and Na_(3)V_(2)(PO_(4))_(3)cathode demonstrate a stable cycling behavior with a reversible specific capacity of~200 m A h g^(-1)at least for 100 cycles.Moreover,advanced synchrotron operando X-ray diffraction,ex-situ X-ray absorption spectroscopy,and comprehensive electrochemical tests reveal the structural transformation and the Co coordination chemistry evolution of the CoS@HDC during cycling,providing fundamental insights into the sodium storage mechanism.
基金supported by the Key Research and Development Program of Wuhan(2025010102030005)the National Nature Science Foundation of Jiangsu Province(BK20221259)。
文摘Carbonaceous material has attracted much attention in the application of sodium-ion batteries(SIBs)anode.However,sluggish reaction kinetics and structure stability impede the application.Therefore,a stacked layered sulfur-carbon complex with long-chain C–S_(x)–C bond(M-SC-S)is prepared.The layered structure ensures structural stability,and long-chain C–S_(x)–C bond expanding interlayer spacing boosts facile Na+diffusion.When assembled into cells,a high-quality solid-electrolyte interphase film would be formed due to a good match between the M-SC-S electrode and ether electrolyte.Moreover,an electrochemical activation process would happen between the Cu current collector and proper S-doped electrode material to in-situ form Cu_(2)S.The formation of Cu_(2)S in active material can not only provide more active sites for sodium storage and enhance pseudo-capacitance,but also reinforce the electrode/current collector interface and decrease the interfacial transfer resistance for rapid Na+kinetics.The synergistic effect of structure design and interface engineering optimizes the sodium storage system.Thus,the M-SC-S electrode delivers an excellent cyclic performance(321.6 mAh g^(−1)after 1000 cycles at 2 A g^(−1)with a capacity retention rate of 97.4%)and good rate capability(282.8 mAh g^(−1)after 4000 cycles even at a high current density of 10 A g^(−1)).The full cell also has an impressive cyclic performance(151.4 mAh g^(−1)after 500 cycles at 0.5 A g^(−1)).
基金supported by the Award Program for Fujian Minjiang Scholar Professorshipthe National Natural Science Foundation of China(21571035)。
文摘Two-dimensional(2D)carbon materials with ultrathin thickness,large lateral size,large surface area,accessible active sites and unique physical-chemical properties have been proven to be attractive electrode materials or catalysts for high-efficient energy storage and conversion materials.However,the conventional synthesis method for 2D carbon materials heavily depends on fossil-based feedstocks and goes through harsh conditions(e.g.,chemical vapor deposition),which are unsustainable and costly.Besides,the top-down method needs to use massive strong acids/oxidants,which is environmentallyunfriendly.Therefore,it is necessary to commit to seek green,sustainable and cost-effective approach for the synthesis of 2D carbon materials.As of now,biomass or biological molecules as carbon-rich resources have been viewed as a promising candidate for the 2D carbon material preparation owing to its abundance,renewability,nontoxicity and low-cost.Especially for nucleobases,as an emerging molecule have been shown great advantages for the construction of 2D materials guided by its multiple hydrogen-bonding interaction.Recently,our group have proposed a rather innovative strategy to produce 2D carbon materials by carbonization of nucleobases which has relatively high electrode potentials.These nucleobases can form planar network structure through hydrogen bonding interaction.Such hydrogenbonding can be stable at relatively high temperature,which confines C-C or C-N polymerization in a 2D plane.As a result,direct carbonization of nucleobases enables the formation of 2D carbon with highly sp2-conjugated and feature of heteroatom doping.This review systematically summarizes the recent development of the strategies to synthesize 2D sustainable carbon materials from biomass and biological molecules.The corresponding electrochemical applications such as lithium ion batteries,supercapacitors and fuel cell are selectively presented.At the end,the summary and future perspectives in this important field are provided to inspire further exploration.
基金The financial supports from the National Natural Science Foundation of China(21605067,21763023)Talent Project Grant of the University of Science and Technology Liaoning(601011507-06)Doctoral Start-up Research Funding of the University of Science and Technology Liaoning(USTL010178),China。
文摘The exploration of active and robust electrocatalysts for both the oxygen reduction reaction(ORR)and oxygen evolution reaction(OER)is the bottleneck to realize the commercialization of rechargeable metal-air batteries and regenerative fuel cells.Here we report facile synthesis of three-dimensional(3 D)carbon nanotube(CNT)/carbon composites using earth-abundant coal as the carbon source,hydrogen reductant and heteroatom dopant to grow CNTs.The prepared composite featuring 3 D structural merits and multiple active sites can efficiently catalyze both ORR and OER,affording high activity,fast kinetics,and long-term stability.With the additional incorporation of manganese,the developed catalyst afforded a potential difference of 0.80 V between ORR at the half wave potential and OER at a current density of 10 mA cm^(-2).The optimized sample has presented excellent OER performance within a constructed solar-powered water splitting system with continuously generating oxygen bubbles at anode.Notably,it can be further used as a durable air-electrode catalyst in constructed Zn-air battery,delivering an initial discharge/charge voltage gap of 0.73 V,a remained voltaic efficiency of 61.2%after 160 cycles and capability to power LED light for at least 80 h.This study provides an efficient approach for converting traditional energy resource i.e.coal to value-added alternative oxygen electrocatalysts in renewable energy conversion systems.
基金This work was supported by the National Key R&D Research Program of China(Nos.2018YFA0209600,2017YFA0208300)the National Natural Science Foundation of China(Nos.51925207,U1910210,51872277,52002083,22005292,51802302)+4 种基金the DNL cooperation Fund,CAS(DNL180310)the Fundamental Research Funds for the Central Universities(WK2060140026,WK3430000006,WK2060000009)the National Synchrotron Radiation Laboratoi-y(KY2060000173)the National Postdoctoral Program for Innovative Talents(BX20200318)the China Postdoctoral Science Foundation(Nos.2020M672533,2019TQ0296,2020M682012).
文摘Potassium-selenium(K-Se)batteries have attracted more and more attention because of their high theoretical specific capacity and natural abundance of K resources.However,dissolution of polyselenides,large volume expansion during cycling and low utilization of Se remain great challenges,leading to poor rate capability and cycle life.Herein,N/O dual-doped carbon nanofibers with interconnected micro/mesopores(MMCFs)are designed as hosts to manipulate Se molecular configuration for advanced flexible K-Se batteries.The micropores play a role in confining small Se molecule(Se_(2–3)),which could inhibit the formation of polyselenides and work as physical barrier to stabilize the cycle performance.While the mesopores can confine long-chain Se(Se_(4–7)),promising sufficient Se loading and contributing to higher discharge voltage of the whole Se@MMCFs composite.The N/O co-doping and the 3D interpenetrating nanostructure improve electrical conductivity and keep the structure integrity after cycling.The obtained Se_(2–3)/Se_(4–7)@MMCFs electrode exhibits an unprecedented cycle life(395 mA h g^(−1) at 1 A g^(−1) after 2000 cycles)and high specific energy density(400 Wh kg^(−1),nearly twice the specific energy density of the Se_(2–3)@MMCFs).This study offers a rational design for the realization of a high energy density and long cycle life chalcogen cathode for energy storage.
基金supported by the National Natural Science Foundation of China(22162004)the Excellent Scholars and Innovation Team of Guangxi Universities,the Innovation Project of Guangxi Graduate Education(YCBZ2022038)the High-performance Computing Platform of Guangxi University。
文摘Herein,the merits of heterojunction,CeO_(2),and W are employed to design and prepare the PtCoW@CeO_(2)heterojunction catalyst,which can accelerate water dissociation and improve the desorption of OHad,displaying efficient hydrogen evolution reaction(HER)performance in pH-universal conditions.Density functional theory calculation results reveal that the electronic structure of Pt is regulated by CeO_(2)and W,which tunes the Pt-Hadbond strength to boost HER intrinsic activity.Consequently,electrochemical results display that it has low potentials of-26,-25,and-23 mV at-10 mA cm^(-2)in alkaline,neutral,and acidic solutions,respectively,and it can stably cycle for 50,000 cycles.Thus,this work provides the guidance for developing high-performance Pt-based catalysts in pH-universal environments.
基金financial support of the National Natural Science Foundation of China(Nos.52100186,52170082,51938007 and 52063024)the Jiangxi Provincial Natural Science Foundation(Nos.20225BCJ23003 and 20212ACB203008)。
文摘Nitrogen-doped carbon loaded single-atom catalysts(SACs)are promising candidates for electrocatalytic conversion of CO_(2)into high-valuable chemicals,and the modification of catalysts by heteroatom-doping strategy is an effective approach to enhance the CO_(2)reduction performance.However,the large difference exists in atomic radius between nitrogen atoms and the doped heteroatoms may lead to the poor stability of active sites.In this study,we have synthesized a Ni single atom catalyst with S doping at the secondshell on the ultrathin carbon nanosheets support(Ni-N_(4)-SC)by solid-phase pyrolysis.The S atom in the second-shell contributes to the higher efficiency of CO_(2)conversion at lower potentials while the Ni-N_(4)-SC can be more stable.The experimental results and theoretical calculations indicate that the S atom in second-shell breaks the uniform charge distribution and reduces the free energy of hydrogenation,which can increase the adsorption of CO_(2),accelerate charge transfer,and reduce the reaction energy barrier.This work reveals the close relationship between the second-shell and the electrocatalytic activity of single atom sites,which also provides a new perspective to design efficient single atom catalysts.
基金This research work is jointly supported and funded by the Scientific and Technological Research Council of Turkey(TÜBİTAK)the Russian Foundation for Basic Research(RFBR)according to the Research Project No.20-58-46014.
文摘Carbyne-enriched nanomaterials are of current interest in nanotechnology-related applications.The properties of these nanomaterials greatly depend on their production process.In particular,structural self-organization and auto-synchronization of nanostructures are typical phenomena observed during the growth and heteroatom-doping of carbyne-enriched nanostructured metamaterials by the ion-assisted pulse-plasma deposition method.Accordingly,fine tuning of these processes may be seen as the key step to the predictive designing of carbyneenriched nano-matrices with improved properties.In particular,we propose an innovative concept,connected with application of the vibrational-acoustic effects and based on universal Cymatics mechanisms.These effects are used to induce vibration-assisted self-organized wave patterns together with the simultaneous manipulation of their properties through an electric field.Interaction between the inhomogeneous electric field distribution generated on the vibrating layer and the plasma ions serves as the additional energizing factor controlling the local pattern formation and self-organization of the nano-structures.
基金This work was jointly supported by the National Key Research and Development Program of China(No.2021YFA1500900)the National Natural Science Foundation of China(No.52071174)the Natural Science Foundation of Jiangsu Province,Major Project(No.BK20212005)。
文摘Metal-free carbon-based catalysts exhibit diverse electrocatalytic performances in CO_(2) reduction reaction(CO_(2)RR),but the attributions and contributions of active sites are still confusing to date.Herein,the hierarchical carbon nanocages(hCNC)doped with different heteroatoms(B,N,P,S)are prepared to examine the impact of dopants on the competitive CO_(2)RR and hydrogen evolution reaction(HER).The hCNC and P-doped hCNC show little CO_(2)RR activity,B-and S-doped hCNC show weak CO_(2)RR activity,while N-doped hCNC presents high CO_(2)RR activity.The CO Faradaic efficiency(FECO)of N-containing hCNC increases almost linearly with increasing the N content,even with the co-existing B or P.S and SN-doped hCNC more facilitate the HER.16 doping configurations are constructed,and up to 53 sites are examined CO_(2) H2O H2 CO*H*COOH*CO for the electrochemical activities with a constant potential modelling method.The pyridinic-N(N^(*))is the best active site for CO_(2)RR to CO,while CBO_(2)H_(2)-1(αC^(*)),CBO_(2)H_(2)-2(γC^(*)),NO-1(βC^(*)),PO_(2)H-3(αC^(*))and SO_(3)H-3(δC^(*))are active for HER.The optimized FECO achieves 83.6%for N-doped hCNC with 9.54 at.%nitrogen,and S-doped hCNC reaches ca.30 mA·cm^(-2) current density for HER.This study unveils the structure-performance correlation of heteroatom-doped hCNC,which is conducive to the rational design of advanced metal-free carbon-based catalysts.
基金partly supported by the National Natural Science Foundation of China(51872035,22078052)the Innovation Program of Dalian City of Liaoning Province(2019RJ03)the Shandong Provincial Natural Science Foundation(ZR2020ZD08)。
文摘For electric double layer supercapacitors,carbon materials originating from the purely physical energystorage mechanism limit the improvement in the capabilities of charge storage.To solve this problem,doping heteroatoms into carbon skeleton is a promising&charming strategy for enhancing electrochemical performance by providing the extra pseudocapacitance.However,the self-discharge behavior of such heteroatom-doped supercapacitors has been a challenging issue for a long time.Here,the porous carbon nanosheets with a tunable total content of heteroatoms are chosen as a demo to systemically decouple the correlation between the total content of heteroatoms and the specific capacitance as well as the self-discharge behavior.The capacitance changes in a range of 164–331 F g^(-1)@1 A g^(-1)with the increased total contents of doped heteroatom,strongly dependent on and sensitive to the total content of heteroatoms.The voltage retention rate and capacitance retention rate for the porous carbon nanosheets with a tunable total content of heteroatoms completely present a quick decline tendency as the increase in the content of heteroatoms,changing from 58%to 34%and 74%to 39%,respectively,indicative of a linear negative relationship.More importantly,the self-discharge mechanisms are elaborately explored and follow the combination of activation-and diffusion-controlled Faradic reactions.This work illustrates the diverse impacts of the doped heteroatoms on the electrochemical performance of supercapacitors,covering specific capacitance and self-discharge behavior,and highlights the importance of balancing the contents of doped heteroatoms in energy storage fields.
基金supported by the National Natural Science Foundation of China (No. 21425312 and 21321002)
文摘Boron had been introduced into the structure of carbon material(BC), which was used as the support of Pd catalyst for hydrogenation of 4-carboxybenzaldehyde(4-CBA). The physical properties and chemical composition of the support and corresponding catalyst were characterized by N2 adsorption–desorption,Raman spectroscopy, inductively coupled plasma optical emission spectroscopy(ICP-OES), element analysis(EA), high-resolution transmission electron microscopy(HRTEM), CO-pulse chemisorption and X-ray photoelectron spectroscopy(XPS). The results demonstrate that Pd/BC catalyst exhibits a superior activity and good stability due to the more uniform dispersion of Pd nanoparticles, the presence of mesoporous structure and the enhanced interaction between Pd nanoparticles and the support, compared to carbon and N-doped carbon supported Pd catalysts(Pd/C and Pd/NC, respectively).
基金the supports from the National Natural Science Foundation of China (Nos. 21503097, 51631004, 51701152, 21806023, and 51702345)Natural Science Foundation of Shaanxi Province (No. 2018JQ5181)。
文摘Hydrogen production from water electrolysis using renewable electricity is a highly promising route to solve the energy crisis of human society. The tetragonal 3d-transition metal selenide with metallic feature has been discovered to efficiently catalyze the hydrogen evolution electrocatalysis;however, its performance is still unsatisfactory and further improvement is necessary. Herein, the hydrogen evolution reaction of the functional tetragonal 3d-transition metal selenide with the heteroatom-dopant as well as cationic vacancy is fully investigated by means of density functional theory calculations. Our results identify 53 promising candidates endowed with good activity due to the absolute free energy of hydrogen adsorption |ΔGH| ≤ 0.30 eV wherein 15 candidates with |ΔG_H| ≤ 0.09 eV possess compelling performance in comparison with the benchmark Pt material. Interestingly, the functional CuSe systems account for 29out of 53 candidates, being high attractive for experimental synthesis. According to the analysis of electronic structure, the enhanced performance stems from the upshift of the sp orbitals, which benefits for the improved affinity toward hydrogen capture. This work provides new direction and guidance for the design of novel electrocatalysts.
基金support from National Science Foundation of China(Nos.21771134,22173067)National Key R&D Program of China(No.2017YFA0204800)+4 种基金Science and Technology Project of Jiangsu Province(No.BZ2020011)Collaborative Innovation Center of Suzhou Nano Science&Technologythe Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)the 111 Projectthe Science and Technology Development Fund,Macao SAR(FDCT No.0052/2021/A)。
文摘The on-purpose direct propane dehydrogenation(PDH) has received extensive attention to meet the everincreasing demand of propylene.In this work,by means of density functional theory(DFT) calculations,we systematically studied the intrinsic coordinating effect of Fe single-atom catalysts in PDH.Interestingly,the N and P dual-coordinated single Fe(Fe-N_(3)P-C) significantly outperform the Fe-N_(4-)C site in catalysis and exhibit desired activity and selectivity at industrial PDH temperatures.The mechanistic origin of different performance on Fe-N_(3)P-C and Fe-N_(4-)C has been ascribed to the geometric effect.To be specific,the in-plane configuration of Fe-N_(4) site exhibits low H affinity,which results in poor activity in C-H bond activations.By contrast,the out-of-plane structure of Fe-N_(3)P-C site exhibits moderate H affinity,which not only promote the C-H bond scission but also offer a platform for obtaining appropriate H diffusion rate which ensures the high selectivity of propylene and the regeneration of catalysts.This work demonstrates promising applications of dual-coordinated single-atom catalysts for highly selective propane dehydrogenation.
基金supported by the National Research Foundation of Korea(NRF-2023R1A2C1004109)supported by Korea Energy(No.2024Research and Development in Field Technology,Yeongheung-01)。
文摘The efficiency of carbon dioxide(CO_(2))adsorption in carbonaceous materials is primarily influenced by their microporosity and thermodynamic affinity for CO_(2).However,achieving optimal heteroatom doping and precise micropore engineering through advanced activation techniques remains a significant challenge.We introduce a solvent-free one-pot method using polythiophene,melamine,and KOH to prepare highly microporous,heteroatom-co-doped carbons(NSC).This approach leverages sulfur from polythiophene,nitrogen from melamine,and the activation agent KOH to enhance CO_(2)capture performance.
基金supported by Korea Research Institute for defense Technology planning and advancement(KRIT)grant funded by the Korea government(Defense Acquisition Program Administration(DAPA))(No.21-107-D00-009,Design and development of core materials and unit cells for seawater secondary batteries,2025).
文摘The development of electrolytes with high ionic conductivity and stable electrode–electrolyte interfaces is crucial for the practical realization of solid-state sodium batteries.In this study,the effect of heteroatom doping in a von-Alpen-type Na super ionic conductor(NASICON)was investigated by substituting Zr^(4+)with Mg^(2+),Zn^(2+),and La^(3+)to enhance its material properties and evaluate its potential for solid-state sodium battery applications.Computational chemistry was employed to predict the thermodynamic stability influenced by dopant introduction and the changes in ionic conductivity arising from crystal structure distortion,with the predictions validated by experiments.The optimized Zn^(2+)-doped NASICON(Zn-NZSP0.07)exhibited the highest total ionic conductivity of 2.74×10^(−3)S∙cm^(−1),representing a 4.5-fold increase compared with undoped NASICON(6.00×10−4 S∙cm^(−1)).The material also showed a high relative density of 99.1%,indicating a compact and well-sintered microstructure,as confirmed by a three-point bending test.Furthermore,a high critical current density of 1.4 mA∙cm^(−2)was achieved in symmetric cell testing.Additionally,a Na_(3)V_(2)(PO_(4))_(3)||Zn-NZSP0.07||Na cell delivered an initial capacity of 103.9 mAh∙g^(−1)at 0.1 A∙g^(−1)and retained 73.4%of its capacity after 200 cycles.These results demonstrate that optimal heteroatom doping is crucial for enhancing the performance of NASICON.
基金supported by the National Natural Science Foundation of China(No.52272258)the Fundamental Research Funds for the Central Universities(No.2021JCCXJD01)Key R&D and transformation projects in Qinghai Province(2023-HZ-801).
文摘Designing efficient bifunctional catalysts with multi-component composites is essential for the application of zinc-air batteries(ZABs).Herein,a bimetallic phosphides-oxides heterostructures coupled heteroatom-doped carbon(FeCoP-FeCo_(2)O_(4)@PNPC)was designed by in-situ growth of phosphor-oxide heterostructures on heteroatom-doped carbon materials and employed as bifunctional electrocatalyst for ZABs.The heteroatom-doped carbon substrate with ORR active sites can effectively improve the conductivity and the double transition metal atoms can enhance the catalytic activity.The heterostructure adjusts the d-band center,making the material gain and loss of electrons are at a medium level,which is conducive to the material’s capture of raw materials and the release of products.is beneficial to electron transfer.The dense FeCo_(2)O_(4)nanorods act as a protection layer to improve stability,and the oxide-phosphide heterostructure and synergistic coupling with the heteroatom-doped carbon substrate also contribute to the catalytic activity.The smallΔE of 0.765 V for catalyzing both OER and ORR,high power density of 121.6 mW·cm^(-2)and the extraordinary long-term stability of more than 240 h for liquid state rechargeable ZAB can be realized.The flexible solid-state rechargeable ZAB with FeCoP-FeCo_(2)O_(4)@PNPC also exhibits superior mechanical flexibility and cycling stability.
基金supported by the National Natural Science Foundation of China(22221001,22131007,22401119)the Science and Technology Major Plan of Gansu Province(23ZDGA012,24JRRA435)+1 种基金the 111 Project(B20027)the Fundamental Research Funds for the Central Universities(lzujbky-2024-jdzx13)。
文摘In ZnIn_(2)S_(4)-based photocatalytic systems,structural optimization and compositional regulation are crucial for significantly enhancing hydrogen production performance.Atom doping and heterostructure formation have been shown to improve solar energy conversion efficiency,thereby boosting photocatalytic performance.However,to date,no one-step synthesis method has been reported that simultaneously constructs hollow heterostructures and introduces heteroatom doping into ZnIn_(2)S_(4)photocatalysts,primarily due to the absence of suitable templates or synthesis strategies.In this study,we propose a novel one-step,coordination-selective strategy based on the hard-soft acid-base theory,using MOF(Ti)as a structure-directing template.By incorporating Ce^(3+),Zn^(2+),In^(3+),and S^(2-),the MOF(Ti)is successfully converted into a hollow MOF(Ce)structure,while Ce-doped ZnIn_(2)S_(4)nanosheets nucleates on its surface.This process yields a highly active 2D/3D hollow core-shell heterojunction photocatalyst,Ce-ZnIn_(2)S_(4)/MOF(Ce).Both theoretical and experimental results demonstrate that this unique structure significantly enhances charge separation and extends the charge carrier's lifetime,leading to markedly improved photocatalytic hydrogen evolution performance.This work offers an innovative and controllable approach for synthesizing MOF-derived hollow core-shell heterojunctions,paving the way for a highly efficient water-splitting system.
基金financially supported by the start-up funding from University of South China(No.220XQD016)the National Natural Science Foundation of China(No.52170164)C.Y.thanks the Australian Research Council(ARC)for financial support through Discovery Project scheme(No.DP19010186).
文摘Developing efficient and cost-effective electrode materials is of essential significance to advance various energy storage technologies,among which flexible supercapacitors hold great promise to meet the growing popularity of wearable electronics.Herein,we report a homologous strategy to parallelly synthesize phosphorus-doped ZnCo_(2)O_(4)(P-ZnCo_(2)O_(4)@NCC)and nitrogen-doped carbon(NC@NCC)both derived from ZnCo-metal-organic frameworks(MOFs)precursors in-situ grown on dopamine-modified carbon cloth(NCC)as conductive substrates.Impressively,the as-obtained P-ZnCo_(2)O_(4)@NCC can achieve a high specific capacitance of 2702.2 mF∙cm^(−2)at 1 mA∙cm^(−2)with the capacitance retention rate exceeding 70.6%at 10 mA∙cm^(−2),demonstrating the outstanding rate capability.Moreover,flexible solid-state hybrid supercapacitors,using P-ZnCo_(2)O_(4)@NCC as positive electrode and NC@NCC as negative electrode,are assembled with poly(vinyl alcohol)(PVA)/KOH as the gel electrolyte,which deliver the energy density of 11.9 mWh∙cm^(−3)when the power density reaches up to 47.3 mW∙cm^(−3).In addition,85.15%of the initial specific capacitance is maintained after 5000 continuous cycles and no obvious capacitance decay is observed under different bending conditions,revealing the excellent cycling stability and flexibility.As a proof-of-concept demonstration,two as-assembled hybrid supercapacitors connected in series can light up a red light-emitting diode(LED)under the bending angle of 180°,heralding the feasibility for broad practical applications.
文摘Heteroatom doping, precise composition control and rational morphology design are efficient strategies for producing novel nanocatalysts for the oxygen reduction reaction （ORR） in fuel cells. Herein, a cost-effective approach to synthesize nitrogen- and sulfur-codoped carbon nanowire aerogels using a hard templating method is proposed. The aerogels prepared using a combination of hydrothermal treatment and carbonization exhibit good catalytic activity for the ORR in alkaline solution. At the optimal annealing temperature and mass ratio between the nitrogen and sulfur precursors, the resultant aerogels show comparable electrocatalytic activity to that of a commercial Pt/C catalyst for the ORR. Importantly, the optimized catalyst shows much better long-term stability and satisfactory tolerance for the methanol crossover effect. These codoped aerogels are expected to have potential applications in fuel cells.
