Exploring efficient and nonprecious metal electrocatalysts of oxygen reduction reaction(ORR)and oxygen evolution reaction(OER)is crucial for developing rechargeable zinc-air batteries(ZABs).Herein,an alloying-degree c...Exploring efficient and nonprecious metal electrocatalysts of oxygen reduction reaction(ORR)and oxygen evolution reaction(OER)is crucial for developing rechargeable zinc-air batteries(ZABs).Herein,an alloying-degree control strategy was employed to fabricate nitrogen-doped carbon sphere(NCS)decorated with dual-phase Co/Co_(7)Fe_(3)heterojunctions(CoFe@NCS).The phase composition of materials has been adjusted by controlling the alloying degree.The optimal CoFe_(0.08)@NCS electrocatalyst displays a half-wave potential of 0.80 V for ORR and an overpotential of 283 mV at 10 mA·cm^(-2)for OER in an alkaline electrolyte.The intriguing bifunctional electrocatalytic activity and durability is attributed to the hierarchically porous structure and interfacial electron coupling of highly-active Co_(7)Fe_(3)alloy and metallic Co species.When the CoFe_(0.08)@NCS material is used as air-cathode catalyst of rechargeable liquid-state zinc-air battery(ZAB),the device shows a high peak power-density(157 mW·cm^(-2))and maintains a stable voltage gap over 150 h,outperforming those of the benchmark(Pt/C+RuO_(2))-based device.In particular,the as-fabricated solid-state flexible ZAB delivers a reliable compatibility under different bending conditions.Our work provides a promising strategy to develop metal/alloy-based electrocatalysts for the application in renewable energy conversion technologies.展开更多
Zinc-air batteries(ZABs)are promising energy storage systems because of high theoretical energy density,safety,low cost,and abundance of zinc.However,the slow multi-step reaction of oxygen and heavy reliance on noble-...Zinc-air batteries(ZABs)are promising energy storage systems because of high theoretical energy density,safety,low cost,and abundance of zinc.However,the slow multi-step reaction of oxygen and heavy reliance on noble-metal catalysts hinder the practical applications of ZABs.Therefore,feasible and advanced non-noble-metal elec-trocatalysts for air cathodes need to be identified to promote the oxygen catalytic reaction.In this review,we initially introduced the advancement of ZABs in the past two decades and provided an overview of key developments in this field.Then,we discussed the work-ing mechanism and the design of bifunctional electrocatalysts from the perspective of morphology design,crystal structure tuning,interface strategy,and atomic engineering.We also included theoretical studies,machine learning,and advanced characterization technologies to provide a comprehensive understanding of the structure-performance relationship of electrocatalysts and the reaction pathways of the oxygen redox reactions.Finally,we discussed the challenges and prospects related to designing advanced non-noble-metal bifunctional electrocatalysts for ZABs.展开更多
The recovery and subsequent reuse of heavy metal ions from industrial wastewater are crucial for promoting sustainable development,but they also presen significant challenges.In this article,ethylenediaminetetraacetic...The recovery and subsequent reuse of heavy metal ions from industrial wastewater are crucial for promoting sustainable development,but they also presen significant challenges.In this article,ethylenediaminetetraacetic dianhydride(EDTAD),which possesses strong metal chelating ability,is covalently attached to MIL-101-NH_(2)(Fe),resulting in a significant improvement in the removal rate of heavy metal ions in wastewater.Furthermore,the recovered waste metal ions are transformed into high-performance FeNi_(3)/NiFe_(2)O_(4)@NC dual-functional oxygen evolution reaction(OER)and oxygen reduction reaction(ORR)catalysts.Specifically,FeNi_(3)/NiFe_(2)O_(4)@NC exhibits outstanding OER performance,with only a264 mV overpotential at 10 mA·cm^(-2).Density functiona theory(DFT)calculations reveal that the synergistic effect of the FeNi_(3)/NiFe_(2)O_(4)@NC heterostructure can enhance conductivity,optimize the free energy of*to OH*during OER reaction,and promote catalytic reactivity.This work not only improves the removal rate of heavy metal ions but also obtains high-performance catalysts,while providing a new approach for the treatment and secondary utilization of heavy metal ion wastewater as well as the preparation of low-cost catalysts.展开更多
To effectively address energy challenges,it is crucial to explore efficient and stable bifunctional nonprecious metal catalysts.In this study,a Mo-doped nickeliron layered double hydroxide with flower-cluster architec...To effectively address energy challenges,it is crucial to explore efficient and stable bifunctional nonprecious metal catalysts.In this study,a Mo-doped nickeliron layered double hydroxide with flower-cluster architecture was successfully prepared by a one-step hydrothermal method,which demonstrated a good water splitting performance.After an appropriate amount of Mo doping,some lattice distortions in the material provided reactive sites for the adsorption and conversion of intermediates,thus optimising the charge distribution of the material.Moreover,the multidimensional void structures formed after doping had a larger specific surface area and accelerated the penetration of the electrolyte,which significantly improved the activity of the catalyst in alkaline media.At 10 mA·cm^(-2),the hydrogen and oxygen evolution overpotentials of Mo-doped nickel-iron double hydroxides(Mo-NiFe LDH/NF-0.2)were 167 and 220 mV,respectively,with an excellent durability up to 24 h.When the Mo-NiFe LDH/NF-0,2 catalyst was used as the cathode and anode of an electrolytic cell,the catalyst achieved a current density of 10 mA·cm^(-2)at an applied voltage of 1.643 V.This study provides a novel approach for designing excellent bifunctional electrocatalysts containing nonprecious metals.展开更多
The development of highly active,stable and inexpensive electrocatalysts for hydrogen production by defects and morphology engineering remains a great challenge.Herein,S vacancies-rich Ni_(3)S_(2)@Cu_(2)S nan-otube he...The development of highly active,stable and inexpensive electrocatalysts for hydrogen production by defects and morphology engineering remains a great challenge.Herein,S vacancies-rich Ni_(3)S_(2)@Cu_(2)S nan-otube heterojunction arrays were in-situ grown on copper foam(V_(s)-Ni_(3)S_(2)@V_(s)-Cu_(2)S NHAs/CF)for efficient electrocatalytic overall water splitting.With the merits of nanotube arrays and efficient electronic mod-ulation drived by the OD vacancy defect and 2D heterojunction defect,the resultant V_(s)-Ni_(3)S_(2)@V_(s)-Cu_(2)S NHAs/CF electrocatalyst exhibits excellent electrocatalytic activity with a low overpotential of 47 mV for the hydrogen evolution reaction(HER)at 10 mA cm^(-2) current density,and 263 mV for the oxygen evolution reaction(OER)at 50 mA cm^(-2) current density,as well as a cell voltage of 1.48 V at 10 mA cm^(-2).Moreover,the nanotube heterojunction arrays endows V_(s)-Ni_(3)S_(2)@V_(s)-Cu_(2)S NHAs/CF with outstanding stability in long-term catalytic processes,as confirmed by the continuous chronopotentiom-etry tests at current densities of 10 mA cm^(-2) for 100 h.展开更多
Hydrogen is a promising candidate for clean and sustainable energy resources to substitute fossil fuels to mitigate global environmental issues.Electrochemical hydrogen production has been regarded as a viable and pro...Hydrogen is a promising candidate for clean and sustainable energy resources to substitute fossil fuels to mitigate global environmental issues.Electrochemical hydrogen production has been regarded as a viable and promising strategy.The overall water splitting is currently the predominant electrochemical hydrogen production method,which could be driven by renewable energy to achieve sustainable production.However,the current challenges are the intrinsically sluggish and energy-intensive oxygen evolution reduction(OER)at the anode and the expensive noble metal-based catalysts for overall water splitting,which limit the practical applications.Extensive efforts have been made to develop bifunctional non-noble metal-based electrocatalysts to boost hydrogen production efficiency and lower the cost.Meanwhile,alternative oxidation reactions with faster kinetics and less energy requirement than OER are being explored as the anodic reaction to couple with the hydrogen evolution reaction for energy-saving hydrogen production.In this review,the non-noble metal-based bifunctional electrocatalysts for overall water splitting,as well as other novel energy-saving hydrogen productions have been introduced and summarized.Current challenges and outlooks are commented on at the end of the article.展开更多
Rational design of bifunctional electrocatalysts for oxygen evolution reaction(OER)and hydrogen evolution reaction(HER)with excellent activity and stability is of great significance,since overall water splitting is a ...Rational design of bifunctional electrocatalysts for oxygen evolution reaction(OER)and hydrogen evolution reaction(HER)with excellent activity and stability is of great significance,since overall water splitting is a promising technology for sustainable conversion of clean energy.However,most electrocatalysts do not simultaneously possess optimal HER/OER activities and their electrical conductivities are intrinsically low,which limit the development of overall water splitting.In this paper,a strategy of electric field treatment is proposed and applied to Ni/Co_(3)O_(4) film to develop a novel bifunctional electrocatalyst.After treated by electric field,the conductive channels consisting of oxygen vacancies are formed in the Co_(3)O_(4) film,which remarkably reduces the resistance of the system by almost 2×10^(4) times.Meanwhile,the surface Ni metal electrode is partially oxidized to nickel oxide,which enhances the catalytic activity.The electric-field-treated Ni/Co_(3)O_(4) material exhibits super outstanding performance of HER,OER,and overall water splitting,and the catalytic activity is significantly superior to the state-of-the-art noble metal catalysts(Pt/C,RuO_(2),and RuO_(2)‖Pt/C couple).This work provides an effective and feasible method for the development of novel and efficient bifunctional electrocatalyst,which is also promising for wide use in the field of catalysis.展开更多
Zn-air batteries have attracted extensive attention for their unique features including high energy density,safety,low cost and environmental friendliness.However,due to their poor chargeability and low efficiency,the...Zn-air batteries have attracted extensive attention for their unique features including high energy density,safety,low cost and environmental friendliness.However,due to their poor chargeability and low efficiency,the practical application remains a challenge.The main obstacles are the intrinsic slow reaction kinetics on air cathodes,including oxygen reduction reaction during the discharging process and oxygen evolution reaction during the recharging process.Searching for efficient bifunctional oxygen electrocatalysts is key to solve these problems.In this review,the configuration and fundamental oxygen electrochemical reactions on air cathodes are briefly introduced for Zn-air batteries first.Then,the latest bifunctional oxygen electrocatalysts are summarized in detail.Finally,the perspectives are provided for the future investigations on bifunctional oxygen electrocatalysts.展开更多
Water-based rechargeable metal-air batteries play an important role in the storage and conversion of renewable electric energy.However,the sluggish kinetics of the oxygen reduction reaction(ORR)and oxygen evolution re...Water-based rechargeable metal-air batteries play an important role in the storage and conversion of renewable electric energy.However,the sluggish kinetics of the oxygen reduction reaction(ORR)and oxygen evolution reaction(OER)have limited the practical application of rechargeable metal-air batteries.Most of reviews were focused on single functional electrocatalysts while few on bifunctional electrocatalysts.It is indispensable but challenging to design a bifunctional electrocatalyst that is active and stable to the two reactions.Recently,attempts to develop high active bifunctional electrocatalysts for both ORR and OER increase rapidly.Much work is focused on the micro-nano design of advanced structures to improve the performance of bifunctional electrocatalyst.Transition-metal materials,carbon materials and composite materials,and the methods developed to prepare micro-nano structures,such as electrochemical methods,chemical vapor deposition,hydrothermal methods and template methods are reported in literatures.Additionally,many strategies,such as adjustments of electronic structures,oxygen defects,metal-oxygen bonds,interfacial strain,nano composites,heteroatom doping etc.,have been used extensively to design bifunctional electrocatalysts.To well understand the achievements in the recent literatures,this review focuses on the micro-nano structural design of materials,and the related methods and strategies are classed into two groups for the improvement of intrinsic and apparent activities.The fine adjustment of nano structures and an in-depth understanding of the reaction mechanism are also discussed briefly.展开更多
The inefficiency of water splitting is mainly due to the sluggish anodic water oxidation reaction. Replacing water oxidation with thermodynamically more favorable selective methanol oxidation reaction and developing r...The inefficiency of water splitting is mainly due to the sluggish anodic water oxidation reaction. Replacing water oxidation with thermodynamically more favorable selective methanol oxidation reaction and developing robust bifunctional electrocatalysts are of great significance. Herein, a hierarchical heteronanostructure with Ni–Co layered double hydroxide(LDH) ultrathin nanosheets coated on cobalt phosphide nanosheets arrays(CoxP@NiCo-LDH) are fabricated and used for co-electrolysis of methanol/water to co-produce value-added formate and hydrogen with saving energy. Benefiting from the fast charge transfer introduced by phosphide nanoarrays, the synergy in nanosheets catalysts with hetero-interface,CoxP@NiCo-LDH/Ni foam(NF) exhibits superior electrocatalytic performance(10 mA cm-2@ 1.24 V and-0.10 V for methanol selective oxidation and hydrogen evolution reaction, respectively). Furthermore,CoxP@NiCo-LDH/NF-based symmetric two-electrode electrolyzer drives a current density of 10 m A cm-2 with a low cell voltage of only 1.43 V and the Faradaic efficiency towards the generation of formate and H2 are close to 100% in the tested range of current density(from 40 to 200 m A cm-2). This work highlights the positive effect of hetero-interaction in the design of more efficient eletrocatalysts and might guide the way towards facile upgrading of alcohols and energy-saving electrolytic H2 co-generation.展开更多
Transition-metal phosphides(TMPs)with high catalytic activity are widely used in the design of electrodes for water splitting.However,a major challenge is how to achieve the trade-off between activity and stability of...Transition-metal phosphides(TMPs)with high catalytic activity are widely used in the design of electrodes for water splitting.However,a major challenge is how to achieve the trade-off between activity and stability of TMPs.Herein,a novel method for synthesizing CoP nanoparticles encapsu-lated in a rich-defect carbon shell(CoP/DCS)is developed through the self-assembly of modified polycyclic aromatic molecules.The graft and removal of high-activity C-N bonds of aromatic molecules render the controllable design of crystallite defects of carbon shell.The density functional theory calculation indicates that the carbon defects with unpaired electrons could effectively tailor the band structure of CoP.Benefiting from the improved activity and corrosion resistance,the CoP/DCS delivers outstanding difunctional hydrogen evolution reaction(88 mV)and oxygen evolution reaction(251 mV)performances at 10 mA cm^(−2)current density.Furthermore,the coupled water electrolyzer with CoP/DCS as both the cathode and anode presents ultralow cell voltages of 1.49 V to achieve 10 mA cm^(−2)with long-time stability.This strategy to improve TMPs electrocatalyst with rich-DCS and heterogeneous structure will inspire the design of other transition metal compound electrocatalysts for water splitting.展开更多
The exploration of low-cost and efficient bifunctional electrocatalysts for oxygen evolution reaction and hydrogen evolution reaction through tuning the chemical composition is strongly required for sustainable resour...The exploration of low-cost and efficient bifunctional electrocatalysts for oxygen evolution reaction and hydrogen evolution reaction through tuning the chemical composition is strongly required for sustainable resources. Herein, we developed a bimetallic cobalt–manganese sulfide supported on Ni foam(CMS/Ni) via a solvothermal method. It has discovered that after combining with the pure Co_9S_8 and Mn S, the morphologies of CMS/Ni have modulated. The obtained three-dimensionally hexagram-like CMS/Ni nanosheets have a significant increase in electrochemical active surface area and charge transport ability. More than that, the synergetic effect of Co and Mn has also presented in this composite. Benefiting from these, the CMS/Ni electrode shows great performance toward hydrogen evolution reaction and oxygen evolution reaction in basic medium, comparing favorably to that ofthe pure Co_9S_8/Ni and Mn S/Ni. More importantly, this versatile CMS/Ni can catalyze the water splitting in a twoelectrode system at a potential of 1.47 V, and this electrolyzer can be efficiently driven by a 1.50 V commercial dry battery.展开更多
The oxygen reduction/evolution reactions(ORR/OER) are a key electrode process in the development of electrochemical energy conversion and storage devices,such as metal-air batteries and reversible fuel cells.The searc...The oxygen reduction/evolution reactions(ORR/OER) are a key electrode process in the development of electrochemical energy conversion and storage devices,such as metal-air batteries and reversible fuel cells.The search for low-cost high-performance nanocarbon-based metal-free and non-precious metal bifunctional electrocatalysts for ORR/OER alternatives to the widely-used noble metal-based catalysts is a research focus.This review aims to outline the opportunities and available options for these nanocarbon-based bifunctional electrocatalysts.Through discussion of some current scientific issues,we summarize the development and breakthroughs of these electrocatalysts.Then we provide our perspectives on these issues and suggestions for some areas in the further work.We hope that this review can improve the interest in nanocarbon-based metal-free and non-precious metal bifunctional electrocatalysts for ORR/OER.展开更多
Sustainable metal-air batteries demand high-efficiency,environmentally-friendly,and non-precious metal-based electrocatalysts with bifunctionality for both the oxygen reduction reaction(ORR)and oxygen evolution reacti...Sustainable metal-air batteries demand high-efficiency,environmentally-friendly,and non-precious metal-based electrocatalysts with bifunctionality for both the oxygen reduction reaction(ORR)and oxygen evolution reaction(OER).In this research,novel functional carbon nanotubes with multi-active sites including well-dispersed single-atom iron throughout the walls and encapsulated ultrafine iron nanoparticles were synthesized as an electrocatalyst(FeNP@Fe-N-C)through one-step pyrolysis of metal-organic frameworks.High-resolution synchrotron powder X-ray diffraction and X-ray absorption spectroscopy were applied to characterize the unique structure of the electrocatalyst.In comparison to the commercial Pt/C and Ru O_(2)electrodes,the newly prepared FeNP@Fe-N-C presented a superb bifunctional performance with its narrow potential difference(Egap)of 0.73 V,which is ascribed to the metallic Fe nanoparticles that boosts the adsorption and activation of oxygen on the active sites with an enhanced O_(2)adsorption capacity of 7.88 cm^(3)g^(-1)and synergistically functionalizes the iron atoms dispersed on the nanotubes.A rechargeable zinc-air battery based on FeNP@Fe-N-C exhibited a superior open-circuit voltage(1.45 V),power density(106.5 m W cm^(-2)),and stable cycling performance.The green technique developed in this work for the fabrication of functional nanotubes raises the prospect of making more efficient electrocatalysts for sustainable energy cells.展开更多
metal oxide electronic interactions in composite electrocatalysts have a considerable impact on their catalytic capability.In this study,we successfully synthesized an electrocatalytic material composed of MoO_(3)/C s...metal oxide electronic interactions in composite electrocatalysts have a considerable impact on their catalytic capability.In this study,we successfully synthesized an electrocatalytic material composed of MoO_(3)/C speciessupported Pd nanoparticles(Pd-MoO_(3)/C)using a convenient hydrothermal method,which exhibited excellent catalytic activities for both ethanol oxidation and oxygen reduction in KOH media.The specific activity of PdMoO_(3)/C toward ethanol oxidation with MoO_(3)loading(40wt%)was~2.6 times greater than that for the commercial Pd/C(10 wt%)with the same Pd content.In particular,the activity could effectively hold up to~60%of its maximum activity after 500-cycle tests,demonstrating improved cyclical stability.Notably,the fast electron transfer kinetics toward oxygen reduction for Pd-MoO_(3)/C(40%)were also comparable to those of commercial Pt/C(20 wt%)catalysts.These superior electrochemical features are primarily derived from the stronger electronic coupling between Pd and MoO_(3)through charge transfer,which can supply more active centers and improve the anti-poisoning ability.Meanwhile,the MoO_(3)species in the Pd-MoO_(3)/C composite may provide additional benefits in terms of electrical conductivity and dispersion.展开更多
Bimetallic metal organic framework(MOF)as a precursor to prepare catalysts with bifunctional catalytic activity of oxygen evolution reaction(OER)and hydrogen evolution reaction(HER)attracts more and more attention.Her...Bimetallic metal organic framework(MOF)as a precursor to prepare catalysts with bifunctional catalytic activity of oxygen evolution reaction(OER)and hydrogen evolution reaction(HER)attracts more and more attention.Herein,hollow oxygen deficiency-enriched NiFe_(2)O_(4) is synthesized by pyrolytic FeNi bimetallic MOF.The defects of rGO during carbonization can act as nucleation sites for FeNi particles.After nucleation and N doping,the FeNi particles were served as catalysts for the deposition of dissolved carbon in the defects of the N/rGO.These deposited carbon,like a bridge,connect N/rGO and hollow oxygen deficiency-enriched NiFe_(2)O_(4) together,which giving full play to the advantages of N/rGO in fast electron transfer,thereby improving its catalytic activity.The resultant NiFe_(2)O_(4)@N/rGO-800 exhibits a low overpotential of 252 mV at 20 mA cm^(-2) for OER and 157 mV at 10 mA cm^(-2) for HER in 1 M KOH,respectively.When used as bifunctional electrodes for overall water splitting,it also shows low cell voltage of 1.60 V and 1.67 V at 10 and 20 mA cm^(-2),respectively.展开更多
The strategy of adopting cheap precursors or abundant resources,which can be obtained directly from nature,is a simple and excellent method of introducing accessible research into environmentally friendly development....The strategy of adopting cheap precursors or abundant resources,which can be obtained directly from nature,is a simple and excellent method of introducing accessible research into environmentally friendly development.Moreover,this is also an urgent requirement for the sustainable development of green technology.Herein,we introduce a simplistic and expandable method to prepare metal-free biomassderived nitrogen self-doped porous activation carbon(N-PAC) with large specific surface area(S_(BET)=1300.58 m^(2)/g).Moreover,the manufactural electrocatalysts exhibit prominent oxygen reduction reaction(ORR) performance in all PH values.As compared with the commercial Pt/C catalyst,the N-PAC/800 with a positive onset potential at 10 mA/cm^(2)(0.93 V),half-wave potential(0.87 V),and limiting current(6.34 mA/cm^(2)) bring to light excellent catalytic stability,selectivity,and much-enhanced methanol tolerance.Furthermore,the prepared electrocatalysts possess considerable hydrogen evolution reaction(HER) performance with a less onset potential of 0.218 V(acidic medium) and0.271 V(alkaline medium) respectively,which can show similar catalytic activity across the whole pH range.Such bifunctional electrocatalyst,with excellent electrocatalytic properties,resource-rich,low cost,and environmental-friendly,hold a promising application in energy conversion and reserve.展开更多
Improving catalytic activity and durabilty through the structural and compositional development of bifunctional electrocatalysts with low cost,high activity and stability is a challenging issue in electrochemical wate...Improving catalytic activity and durabilty through the structural and compositional development of bifunctional electrocatalysts with low cost,high activity and stability is a challenging issue in electrochemical water splitting.Herein,we report the fabrication of heterostructured P-CoMoO_(4)@NiCoP on a Ni foam substrate through interface engineering,by adjusting its composition and architecture.Benefitting from the tailored electronic structure and exposed active sites,the heterostructured P-CoMoO_(4)@NiCoP/NF arrays can be coordinated to boost the overall water splitting.In addition,the superhydrophilic and superaerophobic properties of P-CoMoO_(4)@NiCoP/NF make it conducive to water dissociation and bubble separation in the electrocatalytic process.The heterostructured PCoMoO_(4)@NiCoP/NF exhibits excellent bifunctional electrocatalysis activity with a low overpotential of 66 mV at 10 mA cm^(-2) for HER and 252 mV at 100 mA cm^(-2) for OER.Only 1.62 V potential is required to deliver 20 mA cm^(-2) in a two-electrode electrolysis system,providing a decent overall water splitting performance.The rational construction of the heterostructure makes it possible to regulate the electronic structures and active sites of the electrocatalysts to promote their catalytic activity.展开更多
Water-splitting reactions such as the hydrogen evolution reaction(HER)and the oxygen evolution reaction(OER)typically require expensive noble metal-based electrocatalysts.This has motivated researchers to develop nove...Water-splitting reactions such as the hydrogen evolution reaction(HER)and the oxygen evolution reaction(OER)typically require expensive noble metal-based electrocatalysts.This has motivated researchers to develop novel,cost-effective electrocatalytic systems.In this study,a new multicomponent nanocomposite was assembled by combining functionalized multiwalled carbon nanotubes,a Cu-based metal–organic framework(MOF)(HKUST-1 or HK),and a sulfidized NiMn-layered double hydroxide(NiMn-S).The resulting nanocomposite,abbreviated as MW/HK/NiMn-S,features a unique architecture,high porosity,numerous electroactive Cu/Ni/Mn sites,fast charge transfer,excellent structural stability,and conductivity.At a current density of 10 mA cm-2,this dual-function electrocatalyst shows remarkable performance,with ultralow overpotential values of 163 mV(OER)or 73 mV(HER),as well as low Tafel slopes(57 and 75 mV dec-1,respectively).Additionally,its high turnover frequency values(4.43 s-1 for OER;3.96 s-1 for HER)are significantly superior to those of standard noble metal-based Pt/C and IrO2 systems.The synergistic effect of the nanocomposite's different components is responsible for its enhanced electrocatalytic performance.A density functional theory study revealed that the multi-interface and multicomponent heterostructure contribute to increased electrical conductivity and decreased energy barrier,resulting in superior electrocatalytic HER/OER activity.This study presents a novel vision for designing advanced electrocatalysts with superior performance in water splitting.Various composites have been utilized in water-splitting applications.This study investigates the use of the MW/HK/NiMn-S electrocatalyst for water splitting for the first time to indicate the synergistic effect between carbon-based materials along with layered double hydroxide compounds and porous compounds of MOF.The unique features of each component in this composite can be an interesting topic in the field of water splitting.展开更多
Developing bifunctional electrocatalysts for overall water splitting reaction is still highly desired but with large challenges. Herein, an amorphous Fe Co Ni-S electrocatalyst was developed using thioacetamide for th...Developing bifunctional electrocatalysts for overall water splitting reaction is still highly desired but with large challenges. Herein, an amorphous Fe Co Ni-S electrocatalyst was developed using thioacetamide for the sulfuration of Fe Co Ni hydroxide during the hydrothermal process. The obtained catalyst exhibited an amorphous structure with hybrid bonds of metal-S bond and metal-O bonds in the catalyst system. The optimized catalyst showed a largely improved bifunctional catalytic ability to drive water splitting reaction in the alkaline electrolyte compared to the Fe Co Ni hydroxide. It required an overpotential of 280 m V and 80 m V(No-IR correction) to offer 10 m A/cm^(2)for water oxidation and reduction respectively;a low cell voltage of 1.55 V was required to reach 10 m A/cm^(2)for the water electrolysis with good stability for12 h. Moreover, this catalyst system showed high catalytic stability, catalytic kinetics, and Faraday efficiency for water splitting reactions. Considering the very low intrinsic activity of Fe Co Ni hydroxide, the efficient bifunctional catalytic ability should result from the newly formed hybrid active sites of metallic metal-S species and the high valence state of metal oxide species. This work is effective in the bifunctional catalytic ability boosting for the transition metal materials by facile sulfuration in the hydrothermal approach.展开更多
基金financially supported by the National Natural Science Foundation of China(No.22279047)the Instrumental Analysis Center of Jiangsu University of Science and Technology。
文摘Exploring efficient and nonprecious metal electrocatalysts of oxygen reduction reaction(ORR)and oxygen evolution reaction(OER)is crucial for developing rechargeable zinc-air batteries(ZABs).Herein,an alloying-degree control strategy was employed to fabricate nitrogen-doped carbon sphere(NCS)decorated with dual-phase Co/Co_(7)Fe_(3)heterojunctions(CoFe@NCS).The phase composition of materials has been adjusted by controlling the alloying degree.The optimal CoFe_(0.08)@NCS electrocatalyst displays a half-wave potential of 0.80 V for ORR and an overpotential of 283 mV at 10 mA·cm^(-2)for OER in an alkaline electrolyte.The intriguing bifunctional electrocatalytic activity and durability is attributed to the hierarchically porous structure and interfacial electron coupling of highly-active Co_(7)Fe_(3)alloy and metallic Co species.When the CoFe_(0.08)@NCS material is used as air-cathode catalyst of rechargeable liquid-state zinc-air battery(ZAB),the device shows a high peak power-density(157 mW·cm^(-2))and maintains a stable voltage gap over 150 h,outperforming those of the benchmark(Pt/C+RuO_(2))-based device.In particular,the as-fabricated solid-state flexible ZAB delivers a reliable compatibility under different bending conditions.Our work provides a promising strategy to develop metal/alloy-based electrocatalysts for the application in renewable energy conversion technologies.
基金the Natural Science Foundation of China(Grant No:22309180)Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No:XDB0600000,XDB0600400)+3 种基金Liaoning Binhai Laboratory,(Grant No:LILBLB-2023-04)Dalian Revitalization Talents Program(Grant No:2022RG01)Youth Science and Technology Foundation of Dalian(Grant No:2023RQ015)the University of Waterloo.
文摘Zinc-air batteries(ZABs)are promising energy storage systems because of high theoretical energy density,safety,low cost,and abundance of zinc.However,the slow multi-step reaction of oxygen and heavy reliance on noble-metal catalysts hinder the practical applications of ZABs.Therefore,feasible and advanced non-noble-metal elec-trocatalysts for air cathodes need to be identified to promote the oxygen catalytic reaction.In this review,we initially introduced the advancement of ZABs in the past two decades and provided an overview of key developments in this field.Then,we discussed the work-ing mechanism and the design of bifunctional electrocatalysts from the perspective of morphology design,crystal structure tuning,interface strategy,and atomic engineering.We also included theoretical studies,machine learning,and advanced characterization technologies to provide a comprehensive understanding of the structure-performance relationship of electrocatalysts and the reaction pathways of the oxygen redox reactions.Finally,we discussed the challenges and prospects related to designing advanced non-noble-metal bifunctional electrocatalysts for ZABs.
基金financially supported by the National Natural Science Foundation of China for Youths(Nos.21701059,21804059 and 51902140)the Natural Science Foundation of Jiangsu Province for Youths(No.BK20170571)。
文摘The recovery and subsequent reuse of heavy metal ions from industrial wastewater are crucial for promoting sustainable development,but they also presen significant challenges.In this article,ethylenediaminetetraacetic dianhydride(EDTAD),which possesses strong metal chelating ability,is covalently attached to MIL-101-NH_(2)(Fe),resulting in a significant improvement in the removal rate of heavy metal ions in wastewater.Furthermore,the recovered waste metal ions are transformed into high-performance FeNi_(3)/NiFe_(2)O_(4)@NC dual-functional oxygen evolution reaction(OER)and oxygen reduction reaction(ORR)catalysts.Specifically,FeNi_(3)/NiFe_(2)O_(4)@NC exhibits outstanding OER performance,with only a264 mV overpotential at 10 mA·cm^(-2).Density functiona theory(DFT)calculations reveal that the synergistic effect of the FeNi_(3)/NiFe_(2)O_(4)@NC heterostructure can enhance conductivity,optimize the free energy of*to OH*during OER reaction,and promote catalytic reactivity.This work not only improves the removal rate of heavy metal ions but also obtains high-performance catalysts,while providing a new approach for the treatment and secondary utilization of heavy metal ion wastewater as well as the preparation of low-cost catalysts.
基金financially supported by the National Natural Science Foundation of China(Nos.62001189 and 51802177)the Joint Funds of the National Natural Science Foundation of China(No.U22A20140)+2 种基金the Youth Innovation Group Plan of Shandong Province(No.2022KJ095)the Plan for the Introduction and Cultivation of Young Innovative Talent in the Colleges and Universities of Shandong ProvinceSupported by Guiding Fund of Zaozhuang Industrial Technology Research Institute of University of Jinan。
文摘To effectively address energy challenges,it is crucial to explore efficient and stable bifunctional nonprecious metal catalysts.In this study,a Mo-doped nickeliron layered double hydroxide with flower-cluster architecture was successfully prepared by a one-step hydrothermal method,which demonstrated a good water splitting performance.After an appropriate amount of Mo doping,some lattice distortions in the material provided reactive sites for the adsorption and conversion of intermediates,thus optimising the charge distribution of the material.Moreover,the multidimensional void structures formed after doping had a larger specific surface area and accelerated the penetration of the electrolyte,which significantly improved the activity of the catalyst in alkaline media.At 10 mA·cm^(-2),the hydrogen and oxygen evolution overpotentials of Mo-doped nickel-iron double hydroxides(Mo-NiFe LDH/NF-0.2)were 167 and 220 mV,respectively,with an excellent durability up to 24 h.When the Mo-NiFe LDH/NF-0,2 catalyst was used as the cathode and anode of an electrolytic cell,the catalyst achieved a current density of 10 mA·cm^(-2)at an applied voltage of 1.643 V.This study provides a novel approach for designing excellent bifunctional electrocatalysts containing nonprecious metals.
基金supported by the National Natural Science Foundation of China under Grant No.52072196,52002200,52102106,52202262,22379081,22379080Major Basic Research Program of Natural Science Foundation of Shandong Province under Grant No.ZR2020zD09the Natural Science Foundation of Shandong Province under Grant No.ZR2020QE063,ZR202108180009,ZR2023QE059.
文摘The development of highly active,stable and inexpensive electrocatalysts for hydrogen production by defects and morphology engineering remains a great challenge.Herein,S vacancies-rich Ni_(3)S_(2)@Cu_(2)S nan-otube heterojunction arrays were in-situ grown on copper foam(V_(s)-Ni_(3)S_(2)@V_(s)-Cu_(2)S NHAs/CF)for efficient electrocatalytic overall water splitting.With the merits of nanotube arrays and efficient electronic mod-ulation drived by the OD vacancy defect and 2D heterojunction defect,the resultant V_(s)-Ni_(3)S_(2)@V_(s)-Cu_(2)S NHAs/CF electrocatalyst exhibits excellent electrocatalytic activity with a low overpotential of 47 mV for the hydrogen evolution reaction(HER)at 10 mA cm^(-2) current density,and 263 mV for the oxygen evolution reaction(OER)at 50 mA cm^(-2) current density,as well as a cell voltage of 1.48 V at 10 mA cm^(-2).Moreover,the nanotube heterojunction arrays endows V_(s)-Ni_(3)S_(2)@V_(s)-Cu_(2)S NHAs/CF with outstanding stability in long-term catalytic processes,as confirmed by the continuous chronopotentiom-etry tests at current densities of 10 mA cm^(-2) for 100 h.
基金financially supported by the National Key R&D Program of China (No. 2021YFA1501101)the National Natural Science Foundation of China (No. NSFC 21771156)the NSFC/RGC Joint Research Scheme Project (N_Poly U502/ 21)
文摘Hydrogen is a promising candidate for clean and sustainable energy resources to substitute fossil fuels to mitigate global environmental issues.Electrochemical hydrogen production has been regarded as a viable and promising strategy.The overall water splitting is currently the predominant electrochemical hydrogen production method,which could be driven by renewable energy to achieve sustainable production.However,the current challenges are the intrinsically sluggish and energy-intensive oxygen evolution reduction(OER)at the anode and the expensive noble metal-based catalysts for overall water splitting,which limit the practical applications.Extensive efforts have been made to develop bifunctional non-noble metal-based electrocatalysts to boost hydrogen production efficiency and lower the cost.Meanwhile,alternative oxidation reactions with faster kinetics and less energy requirement than OER are being explored as the anodic reaction to couple with the hydrogen evolution reaction for energy-saving hydrogen production.In this review,the non-noble metal-based bifunctional electrocatalysts for overall water splitting,as well as other novel energy-saving hydrogen productions have been introduced and summarized.Current challenges and outlooks are commented on at the end of the article.
基金supported by the program B for Outstanding PhD candidate of Nanjing University.
文摘Rational design of bifunctional electrocatalysts for oxygen evolution reaction(OER)and hydrogen evolution reaction(HER)with excellent activity and stability is of great significance,since overall water splitting is a promising technology for sustainable conversion of clean energy.However,most electrocatalysts do not simultaneously possess optimal HER/OER activities and their electrical conductivities are intrinsically low,which limit the development of overall water splitting.In this paper,a strategy of electric field treatment is proposed and applied to Ni/Co_(3)O_(4) film to develop a novel bifunctional electrocatalyst.After treated by electric field,the conductive channels consisting of oxygen vacancies are formed in the Co_(3)O_(4) film,which remarkably reduces the resistance of the system by almost 2×10^(4) times.Meanwhile,the surface Ni metal electrode is partially oxidized to nickel oxide,which enhances the catalytic activity.The electric-field-treated Ni/Co_(3)O_(4) material exhibits super outstanding performance of HER,OER,and overall water splitting,and the catalytic activity is significantly superior to the state-of-the-art noble metal catalysts(Pt/C,RuO_(2),and RuO_(2)‖Pt/C couple).This work provides an effective and feasible method for the development of novel and efficient bifunctional electrocatalyst,which is also promising for wide use in the field of catalysis.
基金supported by the National Natural Science Foundation of China NSFC(51702166)Tianjin Municipal Science and Technology Bureau(17JCZDJC37100)~~
文摘Zn-air batteries have attracted extensive attention for their unique features including high energy density,safety,low cost and environmental friendliness.However,due to their poor chargeability and low efficiency,the practical application remains a challenge.The main obstacles are the intrinsic slow reaction kinetics on air cathodes,including oxygen reduction reaction during the discharging process and oxygen evolution reaction during the recharging process.Searching for efficient bifunctional oxygen electrocatalysts is key to solve these problems.In this review,the configuration and fundamental oxygen electrochemical reactions on air cathodes are briefly introduced for Zn-air batteries first.Then,the latest bifunctional oxygen electrocatalysts are summarized in detail.Finally,the perspectives are provided for the future investigations on bifunctional oxygen electrocatalysts.
基金the financial supports from the National Natural Science Foundation of China(91545202,U1508203)the Strategic Priority Research Program of the Chinese Academy of Sciences(CAS)(XDB17000000)+1 种基金the Youth Innovation Promotion Association of the Chinese Academy of Sciencesthe Liaoning Revitalization Talents Program(XLYC1807066)~~
文摘Water-based rechargeable metal-air batteries play an important role in the storage and conversion of renewable electric energy.However,the sluggish kinetics of the oxygen reduction reaction(ORR)and oxygen evolution reaction(OER)have limited the practical application of rechargeable metal-air batteries.Most of reviews were focused on single functional electrocatalysts while few on bifunctional electrocatalysts.It is indispensable but challenging to design a bifunctional electrocatalyst that is active and stable to the two reactions.Recently,attempts to develop high active bifunctional electrocatalysts for both ORR and OER increase rapidly.Much work is focused on the micro-nano design of advanced structures to improve the performance of bifunctional electrocatalyst.Transition-metal materials,carbon materials and composite materials,and the methods developed to prepare micro-nano structures,such as electrochemical methods,chemical vapor deposition,hydrothermal methods and template methods are reported in literatures.Additionally,many strategies,such as adjustments of electronic structures,oxygen defects,metal-oxygen bonds,interfacial strain,nano composites,heteroatom doping etc.,have been used extensively to design bifunctional electrocatalysts.To well understand the achievements in the recent literatures,this review focuses on the micro-nano structural design of materials,and the related methods and strategies are classed into two groups for the improvement of intrinsic and apparent activities.The fine adjustment of nano structures and an in-depth understanding of the reaction mechanism are also discussed briefly.
基金financially supported by the National Natural Science Foundation of China(Nos.21975163 and 21905181)。
文摘The inefficiency of water splitting is mainly due to the sluggish anodic water oxidation reaction. Replacing water oxidation with thermodynamically more favorable selective methanol oxidation reaction and developing robust bifunctional electrocatalysts are of great significance. Herein, a hierarchical heteronanostructure with Ni–Co layered double hydroxide(LDH) ultrathin nanosheets coated on cobalt phosphide nanosheets arrays(CoxP@NiCo-LDH) are fabricated and used for co-electrolysis of methanol/water to co-produce value-added formate and hydrogen with saving energy. Benefiting from the fast charge transfer introduced by phosphide nanoarrays, the synergy in nanosheets catalysts with hetero-interface,CoxP@NiCo-LDH/Ni foam(NF) exhibits superior electrocatalytic performance(10 mA cm-2@ 1.24 V and-0.10 V for methanol selective oxidation and hydrogen evolution reaction, respectively). Furthermore,CoxP@NiCo-LDH/NF-based symmetric two-electrode electrolyzer drives a current density of 10 m A cm-2 with a low cell voltage of only 1.43 V and the Faradaic efficiency towards the generation of formate and H2 are close to 100% in the tested range of current density(from 40 to 200 m A cm-2). This work highlights the positive effect of hetero-interaction in the design of more efficient eletrocatalysts and might guide the way towards facile upgrading of alcohols and energy-saving electrolytic H2 co-generation.
基金Youth Innovation Promotion Association of the Chinese Academy of Sciences,Grant/Award Number:2021174National Natural Science Foundation of China,Grant/Award Number:51902326Natural Science Foundation of Shanxi Province,Grant/Award Numbers:201901D211588,20210302124421。
文摘Transition-metal phosphides(TMPs)with high catalytic activity are widely used in the design of electrodes for water splitting.However,a major challenge is how to achieve the trade-off between activity and stability of TMPs.Herein,a novel method for synthesizing CoP nanoparticles encapsu-lated in a rich-defect carbon shell(CoP/DCS)is developed through the self-assembly of modified polycyclic aromatic molecules.The graft and removal of high-activity C-N bonds of aromatic molecules render the controllable design of crystallite defects of carbon shell.The density functional theory calculation indicates that the carbon defects with unpaired electrons could effectively tailor the band structure of CoP.Benefiting from the improved activity and corrosion resistance,the CoP/DCS delivers outstanding difunctional hydrogen evolution reaction(88 mV)and oxygen evolution reaction(251 mV)performances at 10 mA cm^(−2)current density.Furthermore,the coupled water electrolyzer with CoP/DCS as both the cathode and anode presents ultralow cell voltages of 1.49 V to achieve 10 mA cm^(−2)with long-time stability.This strategy to improve TMPs electrocatalyst with rich-DCS and heterogeneous structure will inspire the design of other transition metal compound electrocatalysts for water splitting.
基金supported by National Natural Science Foundation of China(21576113 and 21376105)Foshan Innovative and Entrepreneurial Research Team Program(No.2014IT100062)
文摘The exploration of low-cost and efficient bifunctional electrocatalysts for oxygen evolution reaction and hydrogen evolution reaction through tuning the chemical composition is strongly required for sustainable resources. Herein, we developed a bimetallic cobalt–manganese sulfide supported on Ni foam(CMS/Ni) via a solvothermal method. It has discovered that after combining with the pure Co_9S_8 and Mn S, the morphologies of CMS/Ni have modulated. The obtained three-dimensionally hexagram-like CMS/Ni nanosheets have a significant increase in electrochemical active surface area and charge transport ability. More than that, the synergetic effect of Co and Mn has also presented in this composite. Benefiting from these, the CMS/Ni electrode shows great performance toward hydrogen evolution reaction and oxygen evolution reaction in basic medium, comparing favorably to that ofthe pure Co_9S_8/Ni and Mn S/Ni. More importantly, this versatile CMS/Ni can catalyze the water splitting in a twoelectrode system at a potential of 1.47 V, and this electrolyzer can be efficiently driven by a 1.50 V commercial dry battery.
基金the financial support provided by the National Natural Science Foundation of China(Grant Nos.51932005 and 21773269)the Joint Research Fund LiaoningShenyang National Laboratory for Materials Science(Grant No.20180510047)Liao Ning Revitalization Talents Program(XLYC1807175)。
文摘The oxygen reduction/evolution reactions(ORR/OER) are a key electrode process in the development of electrochemical energy conversion and storage devices,such as metal-air batteries and reversible fuel cells.The search for low-cost high-performance nanocarbon-based metal-free and non-precious metal bifunctional electrocatalysts for ORR/OER alternatives to the widely-used noble metal-based catalysts is a research focus.This review aims to outline the opportunities and available options for these nanocarbon-based bifunctional electrocatalysts.Through discussion of some current scientific issues,we summarize the development and breakthroughs of these electrocatalysts.Then we provide our perspectives on these issues and suggestions for some areas in the further work.We hope that this review can improve the interest in nanocarbon-based metal-free and non-precious metal bifunctional electrocatalysts for ORR/OER.
基金financially supported by grants 17210219 and T21-711/16R from the Research Grants Council of the Hong Kong governmentproject 51978369 from the National Natural Science Foundation of China。
文摘Sustainable metal-air batteries demand high-efficiency,environmentally-friendly,and non-precious metal-based electrocatalysts with bifunctionality for both the oxygen reduction reaction(ORR)and oxygen evolution reaction(OER).In this research,novel functional carbon nanotubes with multi-active sites including well-dispersed single-atom iron throughout the walls and encapsulated ultrafine iron nanoparticles were synthesized as an electrocatalyst(FeNP@Fe-N-C)through one-step pyrolysis of metal-organic frameworks.High-resolution synchrotron powder X-ray diffraction and X-ray absorption spectroscopy were applied to characterize the unique structure of the electrocatalyst.In comparison to the commercial Pt/C and Ru O_(2)electrodes,the newly prepared FeNP@Fe-N-C presented a superb bifunctional performance with its narrow potential difference(Egap)of 0.73 V,which is ascribed to the metallic Fe nanoparticles that boosts the adsorption and activation of oxygen on the active sites with an enhanced O_(2)adsorption capacity of 7.88 cm^(3)g^(-1)and synergistically functionalizes the iron atoms dispersed on the nanotubes.A rechargeable zinc-air battery based on FeNP@Fe-N-C exhibited a superior open-circuit voltage(1.45 V),power density(106.5 m W cm^(-2)),and stable cycling performance.The green technique developed in this work for the fabrication of functional nanotubes raises the prospect of making more efficient electrocatalysts for sustainable energy cells.
基金financially supported by the Natural Science Foundation of Shanxi Province(No.201901D111277)the National Natural Science Foundation of China(No.21571119)+1 种基金the Graduate Science and Technology Innovation Project Foundation of Shanxi Normal University(No.2021DCXM71)the Program for New Century Excellent Talents in University(No.NCET-12-1035)。
文摘metal oxide electronic interactions in composite electrocatalysts have a considerable impact on their catalytic capability.In this study,we successfully synthesized an electrocatalytic material composed of MoO_(3)/C speciessupported Pd nanoparticles(Pd-MoO_(3)/C)using a convenient hydrothermal method,which exhibited excellent catalytic activities for both ethanol oxidation and oxygen reduction in KOH media.The specific activity of PdMoO_(3)/C toward ethanol oxidation with MoO_(3)loading(40wt%)was~2.6 times greater than that for the commercial Pd/C(10 wt%)with the same Pd content.In particular,the activity could effectively hold up to~60%of its maximum activity after 500-cycle tests,demonstrating improved cyclical stability.Notably,the fast electron transfer kinetics toward oxygen reduction for Pd-MoO_(3)/C(40%)were also comparable to those of commercial Pt/C(20 wt%)catalysts.These superior electrochemical features are primarily derived from the stronger electronic coupling between Pd and MoO_(3)through charge transfer,which can supply more active centers and improve the anti-poisoning ability.Meanwhile,the MoO_(3)species in the Pd-MoO_(3)/C composite may provide additional benefits in terms of electrical conductivity and dispersion.
基金financially supported by the National Natural Science Foundation of China(Nos.21878231,21676202 and 51603145)Natural Science Foundation of Tianjin(Nos.19JCZDJC37300 and 17JCZDJC38100)supported by the Science and Technology Plans of Tianjin(Nos.17PTSYJC00040 and 18PTSYJC00180)。
文摘Bimetallic metal organic framework(MOF)as a precursor to prepare catalysts with bifunctional catalytic activity of oxygen evolution reaction(OER)and hydrogen evolution reaction(HER)attracts more and more attention.Herein,hollow oxygen deficiency-enriched NiFe_(2)O_(4) is synthesized by pyrolytic FeNi bimetallic MOF.The defects of rGO during carbonization can act as nucleation sites for FeNi particles.After nucleation and N doping,the FeNi particles were served as catalysts for the deposition of dissolved carbon in the defects of the N/rGO.These deposited carbon,like a bridge,connect N/rGO and hollow oxygen deficiency-enriched NiFe_(2)O_(4) together,which giving full play to the advantages of N/rGO in fast electron transfer,thereby improving its catalytic activity.The resultant NiFe_(2)O_(4)@N/rGO-800 exhibits a low overpotential of 252 mV at 20 mA cm^(-2) for OER and 157 mV at 10 mA cm^(-2) for HER in 1 M KOH,respectively.When used as bifunctional electrodes for overall water splitting,it also shows low cell voltage of 1.60 V and 1.67 V at 10 and 20 mA cm^(-2),respectively.
基金supported by the National Natural Science Foundation of China(Nos.21673290,U1662103)Science Foundation of China University of Petroleum,Beijing(No.2462017YJRC027)the Strategic Cooperation Technology Projects of CNPC and CUPB(No.ZLZX2020-04)。
文摘The strategy of adopting cheap precursors or abundant resources,which can be obtained directly from nature,is a simple and excellent method of introducing accessible research into environmentally friendly development.Moreover,this is also an urgent requirement for the sustainable development of green technology.Herein,we introduce a simplistic and expandable method to prepare metal-free biomassderived nitrogen self-doped porous activation carbon(N-PAC) with large specific surface area(S_(BET)=1300.58 m^(2)/g).Moreover,the manufactural electrocatalysts exhibit prominent oxygen reduction reaction(ORR) performance in all PH values.As compared with the commercial Pt/C catalyst,the N-PAC/800 with a positive onset potential at 10 mA/cm^(2)(0.93 V),half-wave potential(0.87 V),and limiting current(6.34 mA/cm^(2)) bring to light excellent catalytic stability,selectivity,and much-enhanced methanol tolerance.Furthermore,the prepared electrocatalysts possess considerable hydrogen evolution reaction(HER) performance with a less onset potential of 0.218 V(acidic medium) and0.271 V(alkaline medium) respectively,which can show similar catalytic activity across the whole pH range.Such bifunctional electrocatalyst,with excellent electrocatalytic properties,resource-rich,low cost,and environmental-friendly,hold a promising application in energy conversion and reserve.
基金The authors acknowledge the National Natural Science Foundation of China(NSFC 91834301,21808046 and 21908037)Anhui Provincial Science and Technology Department Foundation(201903a05020021 and 202003a05020046)for funding support.
文摘Improving catalytic activity and durabilty through the structural and compositional development of bifunctional electrocatalysts with low cost,high activity and stability is a challenging issue in electrochemical water splitting.Herein,we report the fabrication of heterostructured P-CoMoO_(4)@NiCoP on a Ni foam substrate through interface engineering,by adjusting its composition and architecture.Benefitting from the tailored electronic structure and exposed active sites,the heterostructured P-CoMoO_(4)@NiCoP/NF arrays can be coordinated to boost the overall water splitting.In addition,the superhydrophilic and superaerophobic properties of P-CoMoO_(4)@NiCoP/NF make it conducive to water dissociation and bubble separation in the electrocatalytic process.The heterostructured PCoMoO_(4)@NiCoP/NF exhibits excellent bifunctional electrocatalysis activity with a low overpotential of 66 mV at 10 mA cm^(-2) for HER and 252 mV at 100 mA cm^(-2) for OER.Only 1.62 V potential is required to deliver 20 mA cm^(-2) in a two-electrode electrolysis system,providing a decent overall water splitting performance.The rational construction of the heterostructure makes it possible to regulate the electronic structures and active sites of the electrocatalysts to promote their catalytic activity.
基金Iran National Science Foundation(INSF)under project No.4025105the Foundation of State Key Laboratory of High-efficiency Utilization of Coal and Green Chemical Engineering(Grant No.2022-K31)+1 种基金the Zhejiang Province Key Research and Development Project(2023 C01191)Alexander M.Kirillov acknowledges the Foundation for Science and Technology(LISBOA-01-0145-FEDER-029697,PTDC/QUIQIN/3898/2020,LA/P/0056/2020,UIDB/00100/2020).
文摘Water-splitting reactions such as the hydrogen evolution reaction(HER)and the oxygen evolution reaction(OER)typically require expensive noble metal-based electrocatalysts.This has motivated researchers to develop novel,cost-effective electrocatalytic systems.In this study,a new multicomponent nanocomposite was assembled by combining functionalized multiwalled carbon nanotubes,a Cu-based metal–organic framework(MOF)(HKUST-1 or HK),and a sulfidized NiMn-layered double hydroxide(NiMn-S).The resulting nanocomposite,abbreviated as MW/HK/NiMn-S,features a unique architecture,high porosity,numerous electroactive Cu/Ni/Mn sites,fast charge transfer,excellent structural stability,and conductivity.At a current density of 10 mA cm-2,this dual-function electrocatalyst shows remarkable performance,with ultralow overpotential values of 163 mV(OER)or 73 mV(HER),as well as low Tafel slopes(57 and 75 mV dec-1,respectively).Additionally,its high turnover frequency values(4.43 s-1 for OER;3.96 s-1 for HER)are significantly superior to those of standard noble metal-based Pt/C and IrO2 systems.The synergistic effect of the nanocomposite's different components is responsible for its enhanced electrocatalytic performance.A density functional theory study revealed that the multi-interface and multicomponent heterostructure contribute to increased electrical conductivity and decreased energy barrier,resulting in superior electrocatalytic HER/OER activity.This study presents a novel vision for designing advanced electrocatalysts with superior performance in water splitting.Various composites have been utilized in water-splitting applications.This study investigates the use of the MW/HK/NiMn-S electrocatalyst for water splitting for the first time to indicate the synergistic effect between carbon-based materials along with layered double hydroxide compounds and porous compounds of MOF.The unique features of each component in this composite can be an interesting topic in the field of water splitting.
基金supported by the National Natural Science Foundation of China (No. 21972124)the Priority Academic Program Development of Jiangsu Higher Education Institutionthe support of the Six Talent Peaks Project of Jiangsu Province (No. XCL-070–2018)。
文摘Developing bifunctional electrocatalysts for overall water splitting reaction is still highly desired but with large challenges. Herein, an amorphous Fe Co Ni-S electrocatalyst was developed using thioacetamide for the sulfuration of Fe Co Ni hydroxide during the hydrothermal process. The obtained catalyst exhibited an amorphous structure with hybrid bonds of metal-S bond and metal-O bonds in the catalyst system. The optimized catalyst showed a largely improved bifunctional catalytic ability to drive water splitting reaction in the alkaline electrolyte compared to the Fe Co Ni hydroxide. It required an overpotential of 280 m V and 80 m V(No-IR correction) to offer 10 m A/cm^(2)for water oxidation and reduction respectively;a low cell voltage of 1.55 V was required to reach 10 m A/cm^(2)for the water electrolysis with good stability for12 h. Moreover, this catalyst system showed high catalytic stability, catalytic kinetics, and Faraday efficiency for water splitting reactions. Considering the very low intrinsic activity of Fe Co Ni hydroxide, the efficient bifunctional catalytic ability should result from the newly formed hybrid active sites of metallic metal-S species and the high valence state of metal oxide species. This work is effective in the bifunctional catalytic ability boosting for the transition metal materials by facile sulfuration in the hydrothermal approach.
