Engineering a phosphide-based multifunctional heterostructure with high redox activity,stability,and efficient charge kinetics for both supercapacitors and water splitting remains challenging due to sluggish reaction ...Engineering a phosphide-based multifunctional heterostructure with high redox activity,stability,and efficient charge kinetics for both supercapacitors and water splitting remains challenging due to sluggish reaction kinetics and structural instability.This study overcomes these challenges by implementing a rapid,energy-efficient approach to develop a MOF-modulated MnP@Cu_(3)P heterostructure via a hydrothermal process followed by high-temperature phosphorization.The heterostructure demonstrates superior redox activity with enhanced stability and improved charge kinetics achieving a high specific capacity of 1131 C g^(-1)as supported by density functional theory findings of increased DOS near the Fermi level.The flexible supercapacitor achieves a peak energy density of 99.20 Wh kg^(-1)and power density of 15.40 kW kg^(-1).Simultaneously,it shows exceptional hydrogen evolution reaction performance with an overpotential of η_(10)=44 mV and η_(1000)=225 mV,attributed to electron transfer from Cu to Mn via P bridging,which shifts the active centers from Mn and Cu sites to the P site,confirmed by lowestΔG_(H)^(*)value of-0.16 eV.The overall water-splitting in full-cell electrocatalyzer delivers cell voltage of E_(20)=1.48 V and E_(1000)=1.88 V and setting a new standard in solar-to-hydrogen efficiency of 20.02%.The electrolyzer cell maintained prolonged stability at industrial-scale current densities of 1.0 A cm^(-2)under alkaline electrolysis achieving an estimated hydrogen production cost of INR 146.7 or US$1.67per kilogram aligning with the cost target of $2/kg by 2026 established by the Clean Hydrogen Electrolysis Program,U.S.department of energy.Furthermore,real-phase demonstration highlights the uninterrupted hydrogen production till 6-minutes via connecting this electrocatalyzer with photovoltaic-charged supercapacitors effectively addressing solar intermittency and gas fluctuations challenges in water-electrolysis.展开更多
The practical application of lithium-sulfur(Li-S)batteries is still impeded by the severe shuttle effect of lithium polysulfides(LiPSs)and sluggish reaction kinetics of active sulfur.Designing catalytic carriers with ...The practical application of lithium-sulfur(Li-S)batteries is still impeded by the severe shuttle effect of lithium polysulfides(LiPSs)and sluggish reaction kinetics of active sulfur.Designing catalytic carriers with abundant active sites and strong chemisorption capability for LiPSs,is regarded as effective strategy to address these issues.Herein,Se-doping is introduced into the nitrogen-doped carbon coated CoP composite(Se-CoP@NC)to generate structural defects,which effectively enlarges the lattice spacing of CoP and reduces the conversion reaction energy barriers of LiPSs.Meanwhile,Se-doping sites bridges the interface of CoP and nitrogen-doped carbon,accelerating the charge transfer behavior and conversion reaction kinetics of LiPSs.Benefiting from the structural advantages,the assembled Li-S batteries with S/Se-CoP@NC as cathode exhibit high reversible capacity of 779.6 mAh/g at 0.5 C after 500 cycles,and high specific capacity of 805.9 mAh/g at 2 C.Even under extreme conditions(high sulfur-loading content of 6.9 mg/cm^(2);lean electrolyte dosage of 7μL/mg),the corresponding Li-S batteries also keep high reversible areal capacity of 4.5 mAh/cm^(2) after 100 cycles at 0.1 C.This work will inspire the design of metal compounds-based catalysts from atomic level to facilitate the practicability of Li-S batteries.展开更多
Cobalt phosphides are potential catalysts to assist the conversion of lithium polysulfides(LiPSs)in lithium-sulfur(Li-S)batteries.However,existing synthesis methods have difficulty precisely tuning their band valences...Cobalt phosphides are potential catalysts to assist the conversion of lithium polysulfides(LiPSs)in lithium-sulfur(Li-S)batteries.However,existing synthesis methods have difficulty precisely tuning their band valences,which is crucial to balancing intermediate products'adsorption and conversion abilities in Li-S batteries.Moreover,studies on the relationship between their band structures and electrochemical performance are limited.Herein,we report cobalt phosphides(Co_(x)P)with a heterogeneous interface of CoP/Co2P embedded in hollow carbon nanofibers(denoted as Co_(x)P@HCNF)via a one-step sequential phosphorization and carbonization strategy,which is applied as an effective interlayer for Li-S batteries.The Co band valence in CoxP was adjusted to regulate the d-p band gap.Theoretical calculations predict that Co_(x)P with a narrowed d-p band center can optimize the electron transfer kinetics and the adsorption affinity with LiPSs.Li-S full cells with a Co_(x)P@HCNF interlayer demonstrated a high specific capacity of1265 mA h g^(-1)at 0.2C and excellent cycle stability of 788 mA h g^(-1)over 400 cycles at 2.0C.A cell with a lean electrolyte(6.0μL mg^(-1))and a high sulfur loading(6.2 mg cm^(-2))delivered a high areal capacity of4.5 mA h cm^(-2)at 0.5C.This study demonstrates that bimetallic coupling-induced electronic-state modulation effectively balances the chemical adsorption and catalytic capability for developing high-performance Li-S batteries.展开更多
High-entropy metal phosphide(HEMP)has considerable potential as an electrocatalyst owing to its beneficial properties,including high-entropy alloy synergy as well as the controllable structure and high conductivity of...High-entropy metal phosphide(HEMP)has considerable potential as an electrocatalyst owing to its beneficial properties,including high-entropy alloy synergy as well as the controllable structure and high conductivity of phosphides.Herein,electrospinning and in situ phosphating were employed to prepare three-dimensional(3D)networks of self-supporting HEMP nanofibers with varying degrees of phosphate content.Comprehensive characterizations via X-ray diffraction and X-ray photoelectron spectroscopy,as well as density functional theory calculations,demonstrate that the introduction of phosphorus(P)atoms to HEMP carbon nanofibers mediates their electronic structure,leads to lattice expansion,which in turn enhances their catalytic performance in the hydrogen evolution reaction(HER).Moreover,the formation of metal-P bonds weakens metal-metal interaction and decreases the free energy of hydrogen adsorption,contributing to the exceptional activity observed in the HEMP catalyst.Electrochemical measurements demonstrate that the HEMP-0.75 catalyst with an ultralow loading of 1.22 wt%ruthenium(Ru)exhibits the highest HER catalytic activity and stability in a 1 M KOH electrolyte,achieving a minimal overpotential of 26 mV at a current density of 10 mA·cm^(-2)and Tafel slope of 50.9 mV·dec^(-1).展开更多
The electronic modulation characteristics of efficient metal phosphide electrocatalysts can be utilized to tune the performance of oxygen evolution reaction(OER).However,improving the overall water splitting performan...The electronic modulation characteristics of efficient metal phosphide electrocatalysts can be utilized to tune the performance of oxygen evolution reaction(OER).However,improving the overall water splitting performance remains a challenging task.By building metal organic framework(MOF)on MOF heterostructures,an efficient strategy for controlling the electrical structure of MOFs was presented in this study.ZIF-67 was in-situ synthesized on MIL-88(Fe)using a two-step self-assembly method,followed by low-temperature phosphorization to ultimately synthesize FeP-CoP_(3)bimetallic phosphides.By combining atomic orbital theory and theoretical calculations(density functional theory),the results reveal the successful modulation of electronic orbitals in FeP-CoP_(3)bimetallic phosphides,which are synthesized from MOF on MOF structure.The synergistic impact of the metal center Co species and the phase conjugation of both kinds of MOFs are responsible for this regulatory phenomenon.Therefore,the catalyst demonstrates excellent properties,demonstrating HER 81 mV(η10)in a 1.0 mol L^(−1)KOH solution and OER 239 mV(η50)low overpotentials.The FeP-CoP_(3)linked dual electrode alkaline batteries,which are bifunctional electrocatalysts,have a good electrocatalytic ability and may last for 50 h.They require just 1.49 V(η50)for total water breakdown.Through this technique,the electrical structure of electrocatalysts may be altered to increase catalytic activity.展开更多
One key step for advancing the widespread practical application of rechargeable metal-air batteries and water electrolysis fundamentally relies on the development of cost-effective multifunctional electrocata-lysts to...One key step for advancing the widespread practical application of rechargeable metal-air batteries and water electrolysis fundamentally relies on the development of cost-effective multifunctional electrocata-lysts toward oxygen and hydrogen-involving reactions.The present work initiates a tofu-derived one-pot strategy for green,facile,and mass production of highly active and stable catalyst toward oxygen reduc-tion/evolution and hydrogen evolution reactions,through the preparation of Fe/Co cross-linked tofu gel and the subsequent pyrolysis.Despite the free use of additional N/P precursors or pore-forming agents,the as-prepared materials comprise highly dispersive FeCo-rich phosphides nanoparticles and porous N,P co-doped carbon network inherited from the tofu skeleton.The resultant catalysts exhibit remarkably enhanced trifunctional activities as compared to the Fe_(2)P and Co_(2)P counterparts,along with better long-term stabilities than the benchmark RuO_(2)and Pt/C catalysts.Accordingly,the as-assembled Zn-air battery delivers a large power density(174 mW cm^(-2))with excellent cycle stability(the gap of charge/discharge voltage@10 mA cm^(-2)increases by 0.01 V after 720 h of operation,vs.0.16 V of Pt/C-RuO_(2)based battery after 378 h).Furthermore,the as-constructed alkaline electrolyzer just requires a small voltage of 1.55 V@10 mA cm^(-2),which outperforms nearly all of those of biomass-derived electrocatalysts ever reported,and that of noble metal catalysts-based electrolyzers(1.72 V@10 mA cm^(-2)for Pt/C-RuO_(2)),underscoring their bright future toward commercial applications in green energy conversion devices.展开更多
The exploitation of electrocatalysts with high activity and durability for HER is desirable for future energy systems,but it is still a challenge.NMPs have attracted increasing attentions,but the preparation process o...The exploitation of electrocatalysts with high activity and durability for HER is desirable for future energy systems,but it is still a challenge.NMPs have attracted increasing attentions,but the preparation process often needs toxic regents or dangerous reaction conditions.Herein,we develop a general green method to fabricate metal-rich NMPs anchored on NPG through pyrolyzing DNA cross-linked complexes.The obtained Ru_(2) P-NPG exhibits an ultrasmall overpotential of 7 mV at 10 mA cm^(2) and ultralow Tafel slope of 33 mV dec^(-1) in 1.0 mol L?1 KOH,even better than that of commercial Pt/C.In addition,Ru 2 P-NPG also shows low overpotentials of 29 and 78 mV in 0.5 mol L^(-1) H_(2)SO_(4) and 1.0 mol L^(-1) PBS,respectively.The superior activity can be attributed to the ultrafine dispersion of Ru 2 P nanoparticles for more accessible sites,more defects formed for abundant active sites,the two-dimensional plane structure for accelerated electron transfer and mass transport,as well as the regulation of electron distribution of the catalyst.Moreover,the synthetic method can also be applied to prepare other metal-rich noble metal phosphides(Pd_(3)P-NPG and Rh_(2)P-NPG),which also exhibits high activity for HER.This work provides an effective strategy for designing NMP-based electrocatalysts.展开更多
Electrocatalytic water splitting is the most directly available route to generate renewable and sustainable hydrogen.Here,we report the design of a composite material in which arrays of square pillar-like NiMoO4nanoro...Electrocatalytic water splitting is the most directly available route to generate renewable and sustainable hydrogen.Here,we report the design of a composite material in which arrays of square pillar-like NiMoO4nanorods coated with N,P-doped carbon layers are uniformly contained in numerous nested nanoparticle structures.The catalysts have superior catalytic activity,requiring only 59 mV and 187 mV for HER and OER to attain a current density of 10 mA/cm^(2),respectively.The assembled two-electrode electrolytic cell required a voltage of 1.48 V to reach 10 mA/cm^(2),along with excellent long-term stability.Theoretical calculations reveal that electrons aggregate and redistribute at the heterogeneous interface,with the d-band centers of the Ni and Fe atoms being positively shifted compared to the Fermi level,effectively optimizing the adsorption of intermediates and reducing the Gibbs free energy,thus accelerating the catalytic process.Meanwhile,an integrated solar-driven water-splitting system demonstrated a high and stable solar-to-hydrogen efficiency of 18.20%.This work provides new possibilities for developing non-precious metal-based bifunctional electrocatalysts for large-scale water splitting applications.展开更多
Designing integrated overall water-splitting catalysts that maintain high efficiency and stability under various conditions is an important trend for future development,yet it remains a significant challenge.Herein,no...Designing integrated overall water-splitting catalysts that maintain high efficiency and stability under various conditions is an important trend for future development,yet it remains a significant challenge.Herein,novel nanoflower-like tri-metallic Ni-Ru-Mo phosphide catalyst((Ni-Ru-Mo)P@F-CDs),integrated with F-doped carbon dots(F-CDs),were synthesized via a straightforward hydrothermal process and subsequent phosphatization.Attributable to precise interface engineering and electronic structure optimization,(Ni-Ru-Mo)P@F-CDs exhibit exceptional bi-functional catalytic activity in alkaline conditions,achieving remarkably low overpotentials of 231 and 123 mV for oxygen evolution reaction(OER)and hydrogen evolution reaction(HER),respectively,at a current density of 100 mA cm^(−2).Industrially,only 1.426 V is needed for the same efficacy.Additionally,the catalyst requires merely 1.508 and 1.564 V for overall water splitting in 1 M KOH and simulated seawater,respectively,at 100 mA cm^(−2).The catalyst also shows excellent stability,with minimal performance decline over 100 h within 100-200 mA cm^(−2).Density functional theory calculations indicate that the interface structure synergistically optimizes Gibbs free energy for H^(*) and O^(*) intermediates during HER and OER,respectively,accelerating electrochemical water-splitting kinetics.展开更多
Among the sustainable energy sources,hydrogen is the one most promising for alleviating the pollution issues related to the usage of conventional fuels,as it can be produced in an efficient and eco-friendly way via el...Among the sustainable energy sources,hydrogen is the one most promising for alleviating the pollution issues related to the usage of conventional fuels,as it can be produced in an efficient and eco-friendly way via electrocatalytic water splitting.The hydrogen evolution reaction(HER,a half-reaction of water splitting)plays a pivotal role in decreasing the price and increasing the catalytic efficiency of hydrogen production and is efficiently promoted by metal phosphides in different electrolytes.Herein,we summarize the recent advances in the development of metal phosphides as HER electrocatalysts,focus on their synthesis(post-treatment,in situ generation,and electrodeposition methods)and the enhancement of their electrocatalytic activity(via elemental doping,interface and vacancy engineering,construction of specific supports and nanostructures,and the design of bior polymetallic phosphides),and highlight the crucial issues and challenges of future development.展开更多
Li-S batteries have been considered as one of advanced next-generation energy storage systems owing to their remarkable theoretical capacity(1672 m Ah g^(-1))and high energy density(2600 Wh kg^(-1)).However,critical i...Li-S batteries have been considered as one of advanced next-generation energy storage systems owing to their remarkable theoretical capacity(1672 m Ah g^(-1))and high energy density(2600 Wh kg^(-1)).However,critical issues,mainly pertaining to lithium polysulfide shuttle and slow sulfur reaction kinetics,have posed a fatal threat to the electrochemical performances of Li-S batteries.The situation is even worse for high sulfur-loaded and flexible cathodes,which are the essential components for practical Li-S batteries.In response,the use of metal compounds as electrocatalysts in Li-S systems have been confirmed as an effective strategy to date.Particularly,recent years have witnessed many progresses in phosphidesoptimized Li-S chemistry.This has been motivated by the superior electron conductivity and high electrocatalytic activity of phosphides.In this tutorial review,we offer a systematic summary of active metal phosphides as promoters for Li-S chemistry,aiming at helping to understanding the working mechanism of phosphide electrocatalysts and guiding the construction of advanced Li-S batteries.展开更多
Hydrogen energy(H_(2)) has been considered as the most possible consummate candidates for replacing the traditional fossil fuels because of its higher combustion heat value and lower environmental pollution.Photocatal...Hydrogen energy(H_(2)) has been considered as the most possible consummate candidates for replacing the traditional fossil fuels because of its higher combustion heat value and lower environmental pollution.Photocatalytic hydrogen evolution(PHE) from water splitting based on semiconductors is a promising technology towards converting solar energy into sustainable H_(2)fuel evolution. Developing high-activity and abundant source semiconductor materials is particularly important to realize highly efficient hydrogen evolution as for photocatalysis technology. However, unmodified pristine photocatalysts are often unable to overcome the weakness of low performance due to their limitations. In recent years, transition metal phosphides(TMPs) were used as valid co-catalysts to replace the classic precious metal materials in the process of photocatalytic reaction owing to their lower cost and higher combustion heat value.What is more, bimetallic phosphides have been also caused widespread concern in H_(2)evolution reaction owing to its much lower overpotential, more superior conductivity, and weaker charge carriers transfer impedance in comparison to those of single metal phosphides. In this minireview, we concluded the latest developments of bimetallic phosphides for a series of photocatalytic reactions. Firstly, we briefly summarize the present loading methods of bimetallic phosphides(BMPs) anchored on the photocatalyst. After that, the H;evolution efficiency based on BMPs as cocatalyst is also studied in detail. Besides, the application of BMPs-based host photocatalyst for H_(2)evolution under dye sensitization effect has also been discussed. At last, the current development prospects and prospective challenges in many ways of BMPs are proposed. We sincerely hope this minireview has certain reference value for great developments of BMPs in the future research.展开更多
The construction of highly active catalysts for methanol oxidation reaction(MOR)is central to direct methanol fuel cells.Tremendous progress has been made in transition metal phosphides(TMPs)based catalysts.However,TM...The construction of highly active catalysts for methanol oxidation reaction(MOR)is central to direct methanol fuel cells.Tremendous progress has been made in transition metal phosphides(TMPs)based catalysts.However,TMPs would be partially damaged and transformed into new substances(e.g.,Pt-M-P composite,where M represents a second transition metal)during Pt deposition process.This would pose a large obstacle to the cognition of the real promoting effects of TMPs in MOR.Herein,Co_(2)P co-catalysts(Pt-P/Co_(2)P@NPC,where NPC stands for N and P co-doped carbon)and Pt-Co-P composite catalysts(Pt-CoP/NPC)were controllably synthesized.Electrocatalysis tests show that the Pt-Co-P/NPC exhibits superior MOR activity as high as 1016 m A/mg_(Pt),significantly exceeding that of Pt-P/Co_(2)P@NPC(345 m A/mg_(Pt)).This result indicates that the promoting effect is ascribed primarily to the resultant Pt-Co-P composite,in sharply contrast to previous viewpoint that Co_(2)P itself improves the activity.Further mechanistic studies reveal that Pt-Co-P/NPC exhibits much stronger electron interaction and thus manifesting a remarkably weaker CO absorption than Pt-P/Co_(2)P@NPC and Pt/C.Moreover,Pt-Co-P is also more capable of producing oxygen-containing adsorbate and thus accelerating the removal of surface-bonded CO^(*),ultimately boosting the MOR performance.展开更多
Lithium−sulfur batteries are one of the most competitive high-energy batteries due to their high theoretical energy density of _(2)600 W·h·kg^(−1).However,their commercialization is limited by poor cycle sta...Lithium−sulfur batteries are one of the most competitive high-energy batteries due to their high theoretical energy density of _(2)600 W·h·kg^(−1).However,their commercialization is limited by poor cycle stability mainly due to the low intrinsic electrical conductivity of sulfur and its discharged products(Li_(2)S_(2)/Li_(2)S),the sluggish reaction kinetics of sulfur cathode,and the“shuttle effect”of soluble intermediate lithi-um polysulfides in ether-based electrolyte.To address these challenges,catalytic hosts have recently been introduced in sulfur cathodes to en-hance the conversion of soluble polysulfides to the final solid products and thus prevent the dissolution and loss of active-sulfur material.In this review,we summarize the recent progress on the use of metal phosphides and borides of different dimensions as the catalytic host of sulfur cathodes and demonstrate the catalytic conversion mechanism of sulfur cathodes with the help of metal phosphides and borides for high-en-ergy and long-life lithium-sulfur batteries.Finally,future outlooks are proposed on developing advanced catalytic host materials to improve battery performance.展开更多
Exploring nonprecious electrocatalysts for water splitting with high efficiency and durability is critically important.Herein,bimetallic phosphides are encapsulated into graphitized carbon to construct a C@NiCoP compo...Exploring nonprecious electrocatalysts for water splitting with high efficiency and durability is critically important.Herein,bimetallic phosphides are encapsulated into graphitized carbon to construct a C@NiCoP composite nanoarray using bimetallic metal-organic framework(MOF) as a self-sacrificial template.The resulting C@NiCoP exhibits superior performance for pH-universal electrocatalytic hydrogen evolution reaction(HER),particularly representing a low overpotential of 46.3 mV at 10 mA cm^(-2) and Tafel slope of 44.1 mV dec^(-1) in alkaline media.The structural characterizations combined with theoretical calculation demonstrate that tailored electronic structure from bimetal atoms and the synergistic effect with graphitized carbon layer could jointly optimize the adsorption ability of hydrogen on active sites in HER process,and enhance the electrical conductivity as well.In addition,the carbon layer served as a protecting shell also prevents highly dispersed NiCoP components from agglomeration and/or loss in harsh media,finally improving the durability.This work thus provides a new insight into optimizing activity and stability of pH-universal electrocatalysts by the nanostructural design and electronic structure modulation.展开更多
Thioetherification between mercaptan and diolefin is an efficient process to remove mercaptans in FCC gasoline at mild condition, during which the selective hydrogenation of diolefin to monoolefin is also expected. He...Thioetherification between mercaptan and diolefin is an efficient process to remove mercaptans in FCC gasoline at mild condition, during which the selective hydrogenation of diolefin to monoolefin is also expected. Here, Si O2 supported transition metal（Fe, Co, Ni, Mo and W） phosphides were tested for the thioetherification of isoprene and butanethiol on a fixed-bed reactor at 120℃ and 1.5 MPa H2, and their structure before and after reaction was characterized by means of XRD, HRTEM, N2 sorption, CO chemisorption, NH3-TPD, XPS and TG. It was found that, among different metal phosphides, Mo P/Si O2 showed the best performance, and the optimal nominal Mo P loading was 25%. Apart from the nature of metal, the density of metal and acid sites determined the catalyst performance. Metal site was mainly responsible for hydrogenation of isoprene, while acid site dominantly contributed to the thioetherification and the polymerization of olefins. Moreover, a balance between metallic and acidic functions is required to arrive at a desired performance. Excessive metal sites or acid sites led to the over-hydrogenation of isoprene or the severe polymerization of olefins, respectively. 25%Mo P/Si O2 was tested for 37 h time on stream, and butanethiol conversion maintained at 100%; although isoprene conversion remarkably decreased, the selectivity to isopentenes exceeded 80% after reaction for 11 h. We suggest that the deactivation of Mo P/Si O2 is mainly ascribed to the butanethiol poisoning and the carbonaceous deposit, especially the former.展开更多
Designing highly active,durable,and nonprecious metal-based bifunctional electrocatalysts for overall water electrolysis is of urgent scientific importance to realize the sustainable hydrogen production,which remains ...Designing highly active,durable,and nonprecious metal-based bifunctional electrocatalysts for overall water electrolysis is of urgent scientific importance to realize the sustainable hydrogen production,which remains a grand challenge.Herein,an innovative approach is demonstrated to synthesize flower-like 3D homogenous trimetallic Mn,Ni,Co phosphide catalysts directly on nickel foam via electrodeposition followed by plasma phosphidation.The electrochemical activity of the catalysts with varying Mn:Ni:Co ratios is assessed to identify the optimal composition,demonstrating that the equimolar trimetallic phosphide yields an outstanding HER catalytic performance with a current density of 10 mA cm^(-2) at an ultra-low overpotential of~14 mV,outperforming the best reported electrocatalysts.This is asserted by the DFT calculations,revealing strong interaction of the metals and the P atom,resulting in enhanced water activation and optimized G_(H)^(*)values for the HER process.Moreover,this optimal composition appreciably catalyzes the OER by exposing more intrinsic active species in-situ formed on the catalyst surface during the OER.Therefore,the Mn_(1)-Ni_(1)-Co_(1)-P-(O)/NF catalyst exhibits a decreased overpotential of~289 mV at 10 mA cm^(-2).More importantly,the electrocatalyst sustains perfect durability up to 48 h at a current density of 10 mA cm^(-2) and continued 5000 cycling stability for both HER and OER.Meanwhile,the assembled MNC-P/NF||MNC-P/NF full water electrolyzer system attains an extremely low cell voltage of 1.48 V at 10 mA cm^(-2).Significantly,the robust stability of the overall system results in a remarkable current retention of~96%after a continuous 50-h run.Therefore,this study provides a facile design and a scalable construction of superb bifunctional ternary MNC-phosphide electrocatalysts for efficient electrochemical energy production systems.展开更多
Exploring feasible synthesis approaches to highly efficient and robust bifunctional electrocatalysts toward both oxygen evolution reaction(OER)and oxygen reduction reaction(ORR)is triggering researcher’s even-increas...Exploring feasible synthesis approaches to highly efficient and robust bifunctional electrocatalysts toward both oxygen evolution reaction(OER)and oxygen reduction reaction(ORR)is triggering researcher’s even-increasing interest in rechargeable Zn-air batteries.Herein,sulfur-doped bimetal FeCo phosphide nanoparticles dispersed on N,P,S-tri-doped graphene(donated as S-FeCo3P/NPSG)are rationally prepared through a controllable one-step carbothermal-phosphorization strategy.The modified charge distribution and electron-donor properties of S-FeCo3P/NPSG caused by S decoration render a significantly beneficial effect on the electrocatalytic activities.Consequently,the S-FeCo3P/NPSG electrode exhibits extraordinary bifunctional activities toward oxygen electrochemistry of the OER overpotential of 290 m V at 10 m A cm^(-2) and the ORR half-wave potential of 0.83 V,approaching to that of noblemetal IrO_(2)(289 m V)and Pt/C(0.84 V),respectively,but with more stronger operation stability in alkaline media.When S-FeCo3P/NPSG serves as the air cathode for liquid-state Zn-air battery,the large peak power density and energy density,as well as superb discharge-charge durability(cycling life>600 h)of this device are obtained.Furthermore,all-solid-state Zn-air battery with S-FeCo3P/NPSG as air electrode also displays excellent mechanical flexibility,high power density and stable cycling stability.The self-reconstruction behavior of the S-FeCo3P/NPSG cathode catalysts is also investigated during the electrocatalytic Zn-air battery operation.This work would provide some novel inspiration from aspects of bonding and charge distribution for the rational construction of active and cost-efficient bifucntional oxygen electrocatalysts for energy storage and conversion devices.展开更多
It is critical to synthesize high-efficiency electrocatalysts to boost the performance of water splitting to meet the requirements of industrial applications. Metal-organic frameworks(MOFs) can function as ideal molec...It is critical to synthesize high-efficiency electrocatalysts to boost the performance of water splitting to meet the requirements of industrial applications. Metal-organic frameworks(MOFs) can function as ideal molecular platforms for the design of highly reactive transition metal phosphides(TMPs), a kind of candidates for high-efficiently electrocatalytic water splitting. The intrinsic activity of the electrocatalysts can be greatly improved via modulating the electronic structure of the catalytic center through the MOF precursors/templates. Moreover, the carbon layer converted in-situ by the organic ligands can not only protect the TMPs from being degraded in the harsh electrochemical environments, but also avoid agglomeration of the catalysts, thereby promoting their activities and stabilities. Furthermore,heteroatom-containing ligands can incorporate N, S or P, etc. atoms into the carbon matrixes after conversion, regulating the coordination microenvironments of the active centers as well as their electronic structures. In this review, we first summarized the latest developments in MOF-derived TMPs by the unique advantages in metal, organic ligand, and morphology regulations for electrocatalytic water splitting. Secondly, we concluded the critical scientific issues currently facing for designing state-of-the-art TMP-based electrocatalysts. Finally, we presented an outlook on this research area, encompassing electrocatalyst construction, catalytic mechanism research, etc.展开更多
Transition metal phosphides are a class of promising electrocatalysts for hydrogen evolution reaction(HER) to replace noble metals.In this work,we for the first time synthesize carbon supported CoP nanoparticles with ...Transition metal phosphides are a class of promising electrocatalysts for hydrogen evolution reaction(HER) to replace noble metals.In this work,we for the first time synthesize carbon supported CoP nanoparticles with the average particle sizes from 3.3 to 9.2 nm,via a solvothermal process followed by low-temperature topological phosphorization,and the size-dependent HER activity of the CoP is investigated by virtue of TEM,XRD,XPS and the electrochemical techniques.It is discovered that the 9.2nm-CoP particles possess high intrinsic HER catalytic activity as compared to the 3.3nm-CoP,although the smaller one displays a high mass activity due to the large surface area.Detailed studies manifest that the small CoP particles suffer from serious oxidation once exposing to air.In contrast,most cobalt remains in the quasi-metallic state in the relatively large CoP particles,which is beneficial for the desorption of Hads,the rate determining step of the HER process over CoP surface.In addition,the low charge transfer resistance across the liquid/solid interfaces also contributes to the excellent HER activity of the relatively large CoP particles.展开更多
基金supported financially by the Ministry of Textiles(Grant No-2/3/2021-NTTM(Pt.)),Govt.of India。
文摘Engineering a phosphide-based multifunctional heterostructure with high redox activity,stability,and efficient charge kinetics for both supercapacitors and water splitting remains challenging due to sluggish reaction kinetics and structural instability.This study overcomes these challenges by implementing a rapid,energy-efficient approach to develop a MOF-modulated MnP@Cu_(3)P heterostructure via a hydrothermal process followed by high-temperature phosphorization.The heterostructure demonstrates superior redox activity with enhanced stability and improved charge kinetics achieving a high specific capacity of 1131 C g^(-1)as supported by density functional theory findings of increased DOS near the Fermi level.The flexible supercapacitor achieves a peak energy density of 99.20 Wh kg^(-1)and power density of 15.40 kW kg^(-1).Simultaneously,it shows exceptional hydrogen evolution reaction performance with an overpotential of η_(10)=44 mV and η_(1000)=225 mV,attributed to electron transfer from Cu to Mn via P bridging,which shifts the active centers from Mn and Cu sites to the P site,confirmed by lowestΔG_(H)^(*)value of-0.16 eV.The overall water-splitting in full-cell electrocatalyzer delivers cell voltage of E_(20)=1.48 V and E_(1000)=1.88 V and setting a new standard in solar-to-hydrogen efficiency of 20.02%.The electrolyzer cell maintained prolonged stability at industrial-scale current densities of 1.0 A cm^(-2)under alkaline electrolysis achieving an estimated hydrogen production cost of INR 146.7 or US$1.67per kilogram aligning with the cost target of $2/kg by 2026 established by the Clean Hydrogen Electrolysis Program,U.S.department of energy.Furthermore,real-phase demonstration highlights the uninterrupted hydrogen production till 6-minutes via connecting this electrocatalyzer with photovoltaic-charged supercapacitors effectively addressing solar intermittency and gas fluctuations challenges in water-electrolysis.
基金the financial support from the National Natural Science Foundation of China(No.52101250)the S&T program of Hebei(Nos.215A4401D and 225A4404D)+5 种基金the Collaborative Innovation Center of Marine Science and Technology of Hainan University(No.XTCX2022HYC14)the Fundamental Research Funds for the Hebei University(No.2021YWF11)the Science Research Project of Hebei Education Department(No.QN2024087)the Xingtai City Natural Science Foundation(No.2023ZZ027)the Key Laboratory of Advanced Energy Materials Chemistry(Ministry of Education),College of Chemistry,Nankai Universitypartially supported by the Pico Election Microscopy Center of Hainan University。
文摘The practical application of lithium-sulfur(Li-S)batteries is still impeded by the severe shuttle effect of lithium polysulfides(LiPSs)and sluggish reaction kinetics of active sulfur.Designing catalytic carriers with abundant active sites and strong chemisorption capability for LiPSs,is regarded as effective strategy to address these issues.Herein,Se-doping is introduced into the nitrogen-doped carbon coated CoP composite(Se-CoP@NC)to generate structural defects,which effectively enlarges the lattice spacing of CoP and reduces the conversion reaction energy barriers of LiPSs.Meanwhile,Se-doping sites bridges the interface of CoP and nitrogen-doped carbon,accelerating the charge transfer behavior and conversion reaction kinetics of LiPSs.Benefiting from the structural advantages,the assembled Li-S batteries with S/Se-CoP@NC as cathode exhibit high reversible capacity of 779.6 mAh/g at 0.5 C after 500 cycles,and high specific capacity of 805.9 mAh/g at 2 C.Even under extreme conditions(high sulfur-loading content of 6.9 mg/cm^(2);lean electrolyte dosage of 7μL/mg),the corresponding Li-S batteries also keep high reversible areal capacity of 4.5 mAh/cm^(2) after 100 cycles at 0.1 C.This work will inspire the design of metal compounds-based catalysts from atomic level to facilitate the practicability of Li-S batteries.
基金support from the National Natural Science Foundation of China(U21A20174)the Fundamental Research Program of Shanxi Province(202203021221049)+3 种基金the Science and Technology Innovation Talent Team Project of Shanxi Province(202304051001010)support from the Shenzhen Science and Technology Program(RCBS20221008093340100)support from the Australian Research Council(ARC)Discovery Early Career Researcher Award(DE230101068)support from the ARC Research Hub for Safe and Reliable Energy(IH200100035)。
文摘Cobalt phosphides are potential catalysts to assist the conversion of lithium polysulfides(LiPSs)in lithium-sulfur(Li-S)batteries.However,existing synthesis methods have difficulty precisely tuning their band valences,which is crucial to balancing intermediate products'adsorption and conversion abilities in Li-S batteries.Moreover,studies on the relationship between their band structures and electrochemical performance are limited.Herein,we report cobalt phosphides(Co_(x)P)with a heterogeneous interface of CoP/Co2P embedded in hollow carbon nanofibers(denoted as Co_(x)P@HCNF)via a one-step sequential phosphorization and carbonization strategy,which is applied as an effective interlayer for Li-S batteries.The Co band valence in CoxP was adjusted to regulate the d-p band gap.Theoretical calculations predict that Co_(x)P with a narrowed d-p band center can optimize the electron transfer kinetics and the adsorption affinity with LiPSs.Li-S full cells with a Co_(x)P@HCNF interlayer demonstrated a high specific capacity of1265 mA h g^(-1)at 0.2C and excellent cycle stability of 788 mA h g^(-1)over 400 cycles at 2.0C.A cell with a lean electrolyte(6.0μL mg^(-1))and a high sulfur loading(6.2 mg cm^(-2))delivered a high areal capacity of4.5 mA h cm^(-2)at 0.5C.This study demonstrates that bimetallic coupling-induced electronic-state modulation effectively balances the chemical adsorption and catalytic capability for developing high-performance Li-S batteries.
基金supported by the National Natural Science Foundation of China(Nos.22103045 and 52273077)the State Key Laboratory of Bio-Fibers and Eco-Textiles,Qingdao University(Nos.ZDKT202108,RZ2000003334 and G2RC202022)support from the Australian National Fabrication Facility’s Queensland Node(No.ANFF-Q),the UQ-Yonsei International Research Project,and the JST-ERATO Yamauchi Materials Space-Tectonics Project(No.JPMJER2003).
文摘High-entropy metal phosphide(HEMP)has considerable potential as an electrocatalyst owing to its beneficial properties,including high-entropy alloy synergy as well as the controllable structure and high conductivity of phosphides.Herein,electrospinning and in situ phosphating were employed to prepare three-dimensional(3D)networks of self-supporting HEMP nanofibers with varying degrees of phosphate content.Comprehensive characterizations via X-ray diffraction and X-ray photoelectron spectroscopy,as well as density functional theory calculations,demonstrate that the introduction of phosphorus(P)atoms to HEMP carbon nanofibers mediates their electronic structure,leads to lattice expansion,which in turn enhances their catalytic performance in the hydrogen evolution reaction(HER).Moreover,the formation of metal-P bonds weakens metal-metal interaction and decreases the free energy of hydrogen adsorption,contributing to the exceptional activity observed in the HEMP catalyst.Electrochemical measurements demonstrate that the HEMP-0.75 catalyst with an ultralow loading of 1.22 wt%ruthenium(Ru)exhibits the highest HER catalytic activity and stability in a 1 M KOH electrolyte,achieving a minimal overpotential of 26 mV at a current density of 10 mA·cm^(-2)and Tafel slope of 50.9 mV·dec^(-1).
文摘The electronic modulation characteristics of efficient metal phosphide electrocatalysts can be utilized to tune the performance of oxygen evolution reaction(OER).However,improving the overall water splitting performance remains a challenging task.By building metal organic framework(MOF)on MOF heterostructures,an efficient strategy for controlling the electrical structure of MOFs was presented in this study.ZIF-67 was in-situ synthesized on MIL-88(Fe)using a two-step self-assembly method,followed by low-temperature phosphorization to ultimately synthesize FeP-CoP_(3)bimetallic phosphides.By combining atomic orbital theory and theoretical calculations(density functional theory),the results reveal the successful modulation of electronic orbitals in FeP-CoP_(3)bimetallic phosphides,which are synthesized from MOF on MOF structure.The synergistic impact of the metal center Co species and the phase conjugation of both kinds of MOFs are responsible for this regulatory phenomenon.Therefore,the catalyst demonstrates excellent properties,demonstrating HER 81 mV(η10)in a 1.0 mol L^(−1)KOH solution and OER 239 mV(η50)low overpotentials.The FeP-CoP_(3)linked dual electrode alkaline batteries,which are bifunctional electrocatalysts,have a good electrocatalytic ability and may last for 50 h.They require just 1.49 V(η50)for total water breakdown.Through this technique,the electrical structure of electrocatalysts may be altered to increase catalytic activity.
基金supported by the National Natural Science Fund for Distinguished Young Scholars(No.52025041)supported by the National Natural Sci-ence Foundation of China(Nos.51702176 and 51974021)+1 种基金Zhejiang Provincial Nature Science Foundation(No.LY20E020009)the Interdisciplinary Research Project for Young Teachers of USTB(Fun-damental Research Funds for the Central Universities,No.FRF-IDRY-21-028).
文摘One key step for advancing the widespread practical application of rechargeable metal-air batteries and water electrolysis fundamentally relies on the development of cost-effective multifunctional electrocata-lysts toward oxygen and hydrogen-involving reactions.The present work initiates a tofu-derived one-pot strategy for green,facile,and mass production of highly active and stable catalyst toward oxygen reduc-tion/evolution and hydrogen evolution reactions,through the preparation of Fe/Co cross-linked tofu gel and the subsequent pyrolysis.Despite the free use of additional N/P precursors or pore-forming agents,the as-prepared materials comprise highly dispersive FeCo-rich phosphides nanoparticles and porous N,P co-doped carbon network inherited from the tofu skeleton.The resultant catalysts exhibit remarkably enhanced trifunctional activities as compared to the Fe_(2)P and Co_(2)P counterparts,along with better long-term stabilities than the benchmark RuO_(2)and Pt/C catalysts.Accordingly,the as-assembled Zn-air battery delivers a large power density(174 mW cm^(-2))with excellent cycle stability(the gap of charge/discharge voltage@10 mA cm^(-2)increases by 0.01 V after 720 h of operation,vs.0.16 V of Pt/C-RuO_(2)based battery after 378 h).Furthermore,the as-constructed alkaline electrolyzer just requires a small voltage of 1.55 V@10 mA cm^(-2),which outperforms nearly all of those of biomass-derived electrocatalysts ever reported,and that of noble metal catalysts-based electrolyzers(1.72 V@10 mA cm^(-2)for Pt/C-RuO_(2)),underscoring their bright future toward commercial applications in green energy conversion devices.
基金This work was supported by the Fundamental Research Funds for the Central Universities(No.2022XJHH02)the National Key Research and Development Program of China(No.2019YFC1907602).
文摘The exploitation of electrocatalysts with high activity and durability for HER is desirable for future energy systems,but it is still a challenge.NMPs have attracted increasing attentions,but the preparation process often needs toxic regents or dangerous reaction conditions.Herein,we develop a general green method to fabricate metal-rich NMPs anchored on NPG through pyrolyzing DNA cross-linked complexes.The obtained Ru_(2) P-NPG exhibits an ultrasmall overpotential of 7 mV at 10 mA cm^(2) and ultralow Tafel slope of 33 mV dec^(-1) in 1.0 mol L?1 KOH,even better than that of commercial Pt/C.In addition,Ru 2 P-NPG also shows low overpotentials of 29 and 78 mV in 0.5 mol L^(-1) H_(2)SO_(4) and 1.0 mol L^(-1) PBS,respectively.The superior activity can be attributed to the ultrafine dispersion of Ru 2 P nanoparticles for more accessible sites,more defects formed for abundant active sites,the two-dimensional plane structure for accelerated electron transfer and mass transport,as well as the regulation of electron distribution of the catalyst.Moreover,the synthetic method can also be applied to prepare other metal-rich noble metal phosphides(Pd_(3)P-NPG and Rh_(2)P-NPG),which also exhibits high activity for HER.This work provides an effective strategy for designing NMP-based electrocatalysts.
基金financially supported by Yunnan Applied Basic Research Projects(Nos.202001BB050006,202201AT070095)Scientific Research Fund Project of Yunnan Provincial Department of Education(No.2023Y0262)Education Reform Research Project of Yunnan University(No.2021Z06)。
文摘Electrocatalytic water splitting is the most directly available route to generate renewable and sustainable hydrogen.Here,we report the design of a composite material in which arrays of square pillar-like NiMoO4nanorods coated with N,P-doped carbon layers are uniformly contained in numerous nested nanoparticle structures.The catalysts have superior catalytic activity,requiring only 59 mV and 187 mV for HER and OER to attain a current density of 10 mA/cm^(2),respectively.The assembled two-electrode electrolytic cell required a voltage of 1.48 V to reach 10 mA/cm^(2),along with excellent long-term stability.Theoretical calculations reveal that electrons aggregate and redistribute at the heterogeneous interface,with the d-band centers of the Ni and Fe atoms being positively shifted compared to the Fermi level,effectively optimizing the adsorption of intermediates and reducing the Gibbs free energy,thus accelerating the catalytic process.Meanwhile,an integrated solar-driven water-splitting system demonstrated a high and stable solar-to-hydrogen efficiency of 18.20%.This work provides new possibilities for developing non-precious metal-based bifunctional electrocatalysts for large-scale water splitting applications.
基金Natural Science Foundation Joint Innovation Fund of Shandong Province,Grant/Award Num ber:ZR2021 LFG019。
文摘Designing integrated overall water-splitting catalysts that maintain high efficiency and stability under various conditions is an important trend for future development,yet it remains a significant challenge.Herein,novel nanoflower-like tri-metallic Ni-Ru-Mo phosphide catalyst((Ni-Ru-Mo)P@F-CDs),integrated with F-doped carbon dots(F-CDs),were synthesized via a straightforward hydrothermal process and subsequent phosphatization.Attributable to precise interface engineering and electronic structure optimization,(Ni-Ru-Mo)P@F-CDs exhibit exceptional bi-functional catalytic activity in alkaline conditions,achieving remarkably low overpotentials of 231 and 123 mV for oxygen evolution reaction(OER)and hydrogen evolution reaction(HER),respectively,at a current density of 100 mA cm^(−2).Industrially,only 1.426 V is needed for the same efficacy.Additionally,the catalyst requires merely 1.508 and 1.564 V for overall water splitting in 1 M KOH and simulated seawater,respectively,at 100 mA cm^(−2).The catalyst also shows excellent stability,with minimal performance decline over 100 h within 100-200 mA cm^(−2).Density functional theory calculations indicate that the interface structure synergistically optimizes Gibbs free energy for H^(*) and O^(*) intermediates during HER and OER,respectively,accelerating electrochemical water-splitting kinetics.
文摘Among the sustainable energy sources,hydrogen is the one most promising for alleviating the pollution issues related to the usage of conventional fuels,as it can be produced in an efficient and eco-friendly way via electrocatalytic water splitting.The hydrogen evolution reaction(HER,a half-reaction of water splitting)plays a pivotal role in decreasing the price and increasing the catalytic efficiency of hydrogen production and is efficiently promoted by metal phosphides in different electrolytes.Herein,we summarize the recent advances in the development of metal phosphides as HER electrocatalysts,focus on their synthesis(post-treatment,in situ generation,and electrodeposition methods)and the enhancement of their electrocatalytic activity(via elemental doping,interface and vacancy engineering,construction of specific supports and nanostructures,and the design of bior polymetallic phosphides),and highlight the crucial issues and challenges of future development.
基金supported by the Project of State Key Laboratory of Environment-Friendly Energy Materials(SWUST,China,Grant Nos.19FKSY16 and 18ZD320304)。
文摘Li-S batteries have been considered as one of advanced next-generation energy storage systems owing to their remarkable theoretical capacity(1672 m Ah g^(-1))and high energy density(2600 Wh kg^(-1)).However,critical issues,mainly pertaining to lithium polysulfide shuttle and slow sulfur reaction kinetics,have posed a fatal threat to the electrochemical performances of Li-S batteries.The situation is even worse for high sulfur-loaded and flexible cathodes,which are the essential components for practical Li-S batteries.In response,the use of metal compounds as electrocatalysts in Li-S systems have been confirmed as an effective strategy to date.Particularly,recent years have witnessed many progresses in phosphidesoptimized Li-S chemistry.This has been motivated by the superior electron conductivity and high electrocatalytic activity of phosphides.In this tutorial review,we offer a systematic summary of active metal phosphides as promoters for Li-S chemistry,aiming at helping to understanding the working mechanism of phosphide electrocatalysts and guiding the construction of advanced Li-S batteries.
基金supported by the National Natural Science Foundation of China (No. 52072153)the NSFC-Shanxi Coal Based Low Carbon Joint Fund (No. U1810117)+2 种基金the Natural Science Foundation of Jiangsu Province (No. BK20190867)Key Scientific Research Projects of Colleges and Universities in Henan Province (No.21A430024)the Young Talent Cultivate Programme of Jiangsu University (No. 4111310017)。
文摘Hydrogen energy(H_(2)) has been considered as the most possible consummate candidates for replacing the traditional fossil fuels because of its higher combustion heat value and lower environmental pollution.Photocatalytic hydrogen evolution(PHE) from water splitting based on semiconductors is a promising technology towards converting solar energy into sustainable H_(2)fuel evolution. Developing high-activity and abundant source semiconductor materials is particularly important to realize highly efficient hydrogen evolution as for photocatalysis technology. However, unmodified pristine photocatalysts are often unable to overcome the weakness of low performance due to their limitations. In recent years, transition metal phosphides(TMPs) were used as valid co-catalysts to replace the classic precious metal materials in the process of photocatalytic reaction owing to their lower cost and higher combustion heat value.What is more, bimetallic phosphides have been also caused widespread concern in H_(2)evolution reaction owing to its much lower overpotential, more superior conductivity, and weaker charge carriers transfer impedance in comparison to those of single metal phosphides. In this minireview, we concluded the latest developments of bimetallic phosphides for a series of photocatalytic reactions. Firstly, we briefly summarize the present loading methods of bimetallic phosphides(BMPs) anchored on the photocatalyst. After that, the H;evolution efficiency based on BMPs as cocatalyst is also studied in detail. Besides, the application of BMPs-based host photocatalyst for H_(2)evolution under dye sensitization effect has also been discussed. At last, the current development prospects and prospective challenges in many ways of BMPs are proposed. We sincerely hope this minireview has certain reference value for great developments of BMPs in the future research.
基金financially supported from the National Natural Science Foundation of China(Nos.12074048 and 12147102)the Project for Fundamental and Frontier Research in Chongqing(No.cstc2020jcyj-msxm X0796)the Fundamental Research Funds for the Central Universities(No.2022CDJXY-002)。
文摘The construction of highly active catalysts for methanol oxidation reaction(MOR)is central to direct methanol fuel cells.Tremendous progress has been made in transition metal phosphides(TMPs)based catalysts.However,TMPs would be partially damaged and transformed into new substances(e.g.,Pt-M-P composite,where M represents a second transition metal)during Pt deposition process.This would pose a large obstacle to the cognition of the real promoting effects of TMPs in MOR.Herein,Co_(2)P co-catalysts(Pt-P/Co_(2)P@NPC,where NPC stands for N and P co-doped carbon)and Pt-Co-P composite catalysts(Pt-CoP/NPC)were controllably synthesized.Electrocatalysis tests show that the Pt-Co-P/NPC exhibits superior MOR activity as high as 1016 m A/mg_(Pt),significantly exceeding that of Pt-P/Co_(2)P@NPC(345 m A/mg_(Pt)).This result indicates that the promoting effect is ascribed primarily to the resultant Pt-Co-P composite,in sharply contrast to previous viewpoint that Co_(2)P itself improves the activity.Further mechanistic studies reveal that Pt-Co-P/NPC exhibits much stronger electron interaction and thus manifesting a remarkably weaker CO absorption than Pt-P/Co_(2)P@NPC and Pt/C.Moreover,Pt-Co-P is also more capable of producing oxygen-containing adsorbate and thus accelerating the removal of surface-bonded CO^(*),ultimately boosting the MOR performance.
基金financially supported by the National Natural Science Foundation of China (Nos. 51725401, 51904030, and 21935006)
文摘Lithium−sulfur batteries are one of the most competitive high-energy batteries due to their high theoretical energy density of _(2)600 W·h·kg^(−1).However,their commercialization is limited by poor cycle stability mainly due to the low intrinsic electrical conductivity of sulfur and its discharged products(Li_(2)S_(2)/Li_(2)S),the sluggish reaction kinetics of sulfur cathode,and the“shuttle effect”of soluble intermediate lithi-um polysulfides in ether-based electrolyte.To address these challenges,catalytic hosts have recently been introduced in sulfur cathodes to en-hance the conversion of soluble polysulfides to the final solid products and thus prevent the dissolution and loss of active-sulfur material.In this review,we summarize the recent progress on the use of metal phosphides and borides of different dimensions as the catalytic host of sulfur cathodes and demonstrate the catalytic conversion mechanism of sulfur cathodes with the help of metal phosphides and borides for high-en-ergy and long-life lithium-sulfur batteries.Finally,future outlooks are proposed on developing advanced catalytic host materials to improve battery performance.
基金supported by the National Natural Science Foundation of China (nos. 21771012, 22038001, 51621003)。
文摘Exploring nonprecious electrocatalysts for water splitting with high efficiency and durability is critically important.Herein,bimetallic phosphides are encapsulated into graphitized carbon to construct a C@NiCoP composite nanoarray using bimetallic metal-organic framework(MOF) as a self-sacrificial template.The resulting C@NiCoP exhibits superior performance for pH-universal electrocatalytic hydrogen evolution reaction(HER),particularly representing a low overpotential of 46.3 mV at 10 mA cm^(-2) and Tafel slope of 44.1 mV dec^(-1) in alkaline media.The structural characterizations combined with theoretical calculation demonstrate that tailored electronic structure from bimetal atoms and the synergistic effect with graphitized carbon layer could jointly optimize the adsorption ability of hydrogen on active sites in HER process,and enhance the electrical conductivity as well.In addition,the carbon layer served as a protecting shell also prevents highly dispersed NiCoP components from agglomeration and/or loss in harsh media,finally improving the durability.This work thus provides a new insight into optimizing activity and stability of pH-universal electrocatalysts by the nanostructural design and electronic structure modulation.
基金supported by the State Key Laboratory of Catalytic Materials and Reaction Engineering(RIPP,SINOPEC)
文摘Thioetherification between mercaptan and diolefin is an efficient process to remove mercaptans in FCC gasoline at mild condition, during which the selective hydrogenation of diolefin to monoolefin is also expected. Here, Si O2 supported transition metal（Fe, Co, Ni, Mo and W） phosphides were tested for the thioetherification of isoprene and butanethiol on a fixed-bed reactor at 120℃ and 1.5 MPa H2, and their structure before and after reaction was characterized by means of XRD, HRTEM, N2 sorption, CO chemisorption, NH3-TPD, XPS and TG. It was found that, among different metal phosphides, Mo P/Si O2 showed the best performance, and the optimal nominal Mo P loading was 25%. Apart from the nature of metal, the density of metal and acid sites determined the catalyst performance. Metal site was mainly responsible for hydrogenation of isoprene, while acid site dominantly contributed to the thioetherification and the polymerization of olefins. Moreover, a balance between metallic and acidic functions is required to arrive at a desired performance. Excessive metal sites or acid sites led to the over-hydrogenation of isoprene or the severe polymerization of olefins, respectively. 25%Mo P/Si O2 was tested for 37 h time on stream, and butanethiol conversion maintained at 100%; although isoprene conversion remarkably decreased, the selectivity to isopentenes exceeded 80% after reaction for 11 h. We suggest that the deactivation of Mo P/Si O2 is mainly ascribed to the butanethiol poisoning and the carbonaceous deposit, especially the former.
文摘Designing highly active,durable,and nonprecious metal-based bifunctional electrocatalysts for overall water electrolysis is of urgent scientific importance to realize the sustainable hydrogen production,which remains a grand challenge.Herein,an innovative approach is demonstrated to synthesize flower-like 3D homogenous trimetallic Mn,Ni,Co phosphide catalysts directly on nickel foam via electrodeposition followed by plasma phosphidation.The electrochemical activity of the catalysts with varying Mn:Ni:Co ratios is assessed to identify the optimal composition,demonstrating that the equimolar trimetallic phosphide yields an outstanding HER catalytic performance with a current density of 10 mA cm^(-2) at an ultra-low overpotential of~14 mV,outperforming the best reported electrocatalysts.This is asserted by the DFT calculations,revealing strong interaction of the metals and the P atom,resulting in enhanced water activation and optimized G_(H)^(*)values for the HER process.Moreover,this optimal composition appreciably catalyzes the OER by exposing more intrinsic active species in-situ formed on the catalyst surface during the OER.Therefore,the Mn_(1)-Ni_(1)-Co_(1)-P-(O)/NF catalyst exhibits a decreased overpotential of~289 mV at 10 mA cm^(-2).More importantly,the electrocatalyst sustains perfect durability up to 48 h at a current density of 10 mA cm^(-2) and continued 5000 cycling stability for both HER and OER.Meanwhile,the assembled MNC-P/NF||MNC-P/NF full water electrolyzer system attains an extremely low cell voltage of 1.48 V at 10 mA cm^(-2).Significantly,the robust stability of the overall system results in a remarkable current retention of~96%after a continuous 50-h run.Therefore,this study provides a facile design and a scalable construction of superb bifunctional ternary MNC-phosphide electrocatalysts for efficient electrochemical energy production systems.
基金supported by the National Natural Science Foundation of China(21875118,22179065,and 22105108)the Natural Science Foundation of Tianjin(19JCZDJC37700)+1 种基金the 111 project(B12015)China Postdoctoral Science Foundation(2020M680860)。
文摘Exploring feasible synthesis approaches to highly efficient and robust bifunctional electrocatalysts toward both oxygen evolution reaction(OER)and oxygen reduction reaction(ORR)is triggering researcher’s even-increasing interest in rechargeable Zn-air batteries.Herein,sulfur-doped bimetal FeCo phosphide nanoparticles dispersed on N,P,S-tri-doped graphene(donated as S-FeCo3P/NPSG)are rationally prepared through a controllable one-step carbothermal-phosphorization strategy.The modified charge distribution and electron-donor properties of S-FeCo3P/NPSG caused by S decoration render a significantly beneficial effect on the electrocatalytic activities.Consequently,the S-FeCo3P/NPSG electrode exhibits extraordinary bifunctional activities toward oxygen electrochemistry of the OER overpotential of 290 m V at 10 m A cm^(-2) and the ORR half-wave potential of 0.83 V,approaching to that of noblemetal IrO_(2)(289 m V)and Pt/C(0.84 V),respectively,but with more stronger operation stability in alkaline media.When S-FeCo3P/NPSG serves as the air cathode for liquid-state Zn-air battery,the large peak power density and energy density,as well as superb discharge-charge durability(cycling life>600 h)of this device are obtained.Furthermore,all-solid-state Zn-air battery with S-FeCo3P/NPSG as air electrode also displays excellent mechanical flexibility,high power density and stable cycling stability.The self-reconstruction behavior of the S-FeCo3P/NPSG cathode catalysts is also investigated during the electrocatalytic Zn-air battery operation.This work would provide some novel inspiration from aspects of bonding and charge distribution for the rational construction of active and cost-efficient bifucntional oxygen electrocatalysts for energy storage and conversion devices.
基金supported by the National Natural Science Foundation of China (21901088, 21901089, 22161021, 21971091)the Natural Science Foundation of Jiangxi Province(20192ACB20013)+1 种基金support of Jiangxi Province (jxsq2018106041)the “Young Elite Scientists Sponsorship Program” by CAST。
文摘It is critical to synthesize high-efficiency electrocatalysts to boost the performance of water splitting to meet the requirements of industrial applications. Metal-organic frameworks(MOFs) can function as ideal molecular platforms for the design of highly reactive transition metal phosphides(TMPs), a kind of candidates for high-efficiently electrocatalytic water splitting. The intrinsic activity of the electrocatalysts can be greatly improved via modulating the electronic structure of the catalytic center through the MOF precursors/templates. Moreover, the carbon layer converted in-situ by the organic ligands can not only protect the TMPs from being degraded in the harsh electrochemical environments, but also avoid agglomeration of the catalysts, thereby promoting their activities and stabilities. Furthermore,heteroatom-containing ligands can incorporate N, S or P, etc. atoms into the carbon matrixes after conversion, regulating the coordination microenvironments of the active centers as well as their electronic structures. In this review, we first summarized the latest developments in MOF-derived TMPs by the unique advantages in metal, organic ligand, and morphology regulations for electrocatalytic water splitting. Secondly, we concluded the critical scientific issues currently facing for designing state-of-the-art TMP-based electrocatalysts. Finally, we presented an outlook on this research area, encompassing electrocatalyst construction, catalytic mechanism research, etc.
基金financially supported by the National Natural Science Foundation of China(21576258,21776146)the Key Research and Development Project of Shandong Province(2018GGX102036)Taishan Scholar Program of Shandong Province(ts201712046)。
文摘Transition metal phosphides are a class of promising electrocatalysts for hydrogen evolution reaction(HER) to replace noble metals.In this work,we for the first time synthesize carbon supported CoP nanoparticles with the average particle sizes from 3.3 to 9.2 nm,via a solvothermal process followed by low-temperature topological phosphorization,and the size-dependent HER activity of the CoP is investigated by virtue of TEM,XRD,XPS and the electrochemical techniques.It is discovered that the 9.2nm-CoP particles possess high intrinsic HER catalytic activity as compared to the 3.3nm-CoP,although the smaller one displays a high mass activity due to the large surface area.Detailed studies manifest that the small CoP particles suffer from serious oxidation once exposing to air.In contrast,most cobalt remains in the quasi-metallic state in the relatively large CoP particles,which is beneficial for the desorption of Hads,the rate determining step of the HER process over CoP surface.In addition,the low charge transfer resistance across the liquid/solid interfaces also contributes to the excellent HER activity of the relatively large CoP particles.
