The performance of hematite(α-Fe_(2)O_(3))photoanodes for photoelectrochemical(PEC)water splitting has been limited to around 2-5 mA cm^(-2)under standard conditions due to their short hole diffusion length and slugg...The performance of hematite(α-Fe_(2)O_(3))photoanodes for photoelectrochemical(PEC)water splitting has been limited to around 2-5 mA cm^(-2)under standard conditions due to their short hole diffusion length and sluggish oxygen evolution reaction kinetics.This work overcomes those challenges through a synergistic strategy that co-designs the hematite architecture and the surface reaction pathway.We introduce a textured and hierarchically porous Ti-doped Fe_(2)O_(3)(tp-Fe_(2)O_(3))photoanode,synthesized via multi-cycle growth and flame annealing method.This unique architecture features a high texture(110),enlarged surface area,and hierarchically porous structure,which enable significantly enhanced bulk charge transport and interfacial charge transfer compared to typical nanorod Ti-doped Fe_(2)O_(3)(nr-Fe_(2)O_(3)).As a result,the tp-Fe_(2)O_(3)photoanode achieves a photocurrent density of 3.1 mA cm^(-2)at 1.23 V vs.RHE with exceptional stability over 105 h,notably without any co-catalyst.By replacing the OER with the hydrazine oxidation reaction,the photocurrent further reaches a record-high level of 7.1 mA cm^(-2)at 1.23 V_(RHE).Finally,when we integrate the tp-Fe_(2)O_(3)with a commercial Si solar cell,it achieves a solar-to-hydrogen efficiency of 8.7%-the highest reported value for any Fe_(2)O_(3)-based PVtandem system.This work provides critical insights into rational Fe_(2)O_(3)photoanode design and highlights the potential of hydrazine as an efficient alternative anodic reaction,enabling waste valorization.展开更多
From an aqueous mixture of Ag(I)-EDTA complex and Ni(II)nitrate,silver and nickel particles were co-deposited on the surface of titanium substrates by the hydrothermal method using hydrazine hydrate as a reduction age...From an aqueous mixture of Ag(I)-EDTA complex and Ni(II)nitrate,silver and nickel particles were co-deposited on the surface of titanium substrates by the hydrothermal method using hydrazine hydrate as a reduction agent.The prepared titanium-supported nano-scale Ag and Ag-Ni particles(nano Ag/Ti,nano Ag86Ni14/Ti,nano Ag77Ni23/Ti,and nano Ag74Ni26/Ti)exhibit nanoporous 3D network textures.Their electrocatalytic activity towards hydrazine oxidation in alkaline solutions was evaluated by cyclic voltammetry and chronoamperometry.The results show that the four samples present a low onset potential of ca.-0.60 V vs.SCE and considerably high and stable anodic current densities for hydrazine oxidation.Among them,the nano Ag86Ni14/Ti electrode exhibits the highest anodic current density towards hydrazine oxidation,showing an increment of electro-active sites on the nano Ag86Ni14/Ti due to the addition of Ni to Ag particles.展开更多
A hydrogen evolution-assisted one-pot aqueous approach was developed for facile synthesis of trimetallic Pd Ni Ru alloy nanochain-like networks（Pd Ni Ru NCNs） by only using KBHas the reductant, without any specific ...A hydrogen evolution-assisted one-pot aqueous approach was developed for facile synthesis of trimetallic Pd Ni Ru alloy nanochain-like networks（Pd Ni Ru NCNs） by only using KBHas the reductant, without any specific additive（e.g. surfactant, polymer, template or seed）. The products were mainly investigated by transmission electron microscopy（TEM）, X-ray diffraction（XRD） and X-ray photoelectron spectroscopy（XPS）. The hierarchical architectures were formed by the oriented assembly growth and the diffusioncontrolled deposition in the presence of many in-situ generated hydrogen bubbles. The architectures had the largest electrochemically active surface area（ECSA） of 84.32 mgPdthan Pd Ni nanoparticles(NPs,65.23 mgPd), Pd Ru NPs(23.12 mgPd), Ni Ru NPs（nearly zero）, and commercial Pd black(6.01 mgPd), outperforming the referenced catalysts regarding the catalytic characters for hydrazine oxygen reaction（HOR）. The synthetic route provides new insight into the preparation of other trimetallic nanocatalysts in fuel cells.展开更多
The development of efficient hydrazine oxidation reaction(HzOR)catalysts is important for the construc-tion of remarkable energy storage and conversion systems.However,after a period of electrochemical reaction,the ac...The development of efficient hydrazine oxidation reaction(HzOR)catalysts is important for the construc-tion of remarkable energy storage and conversion systems.However,after a period of electrochemical reaction,the active site of the catalyst will be irreversibly reduced or inactivated,and how to recover the active site is a major challenge.Here,we report 2D Co(OH)_(2)/Ti_(3)C_(2)(OH)_(x)MXene composites with rapid re-construction and self-healing behaviors as efficient and stable electrocatalysts during HzOR process.Both experimental and theoretical results indicate that the introduction of Ti_(3)C_(2)(OH)_(x)MXene can effectively reduce the dehydrogenation barrier of Co(OH)_(2),from 0.584 eV to 0.481 eV to form the real catalytic active center Co(OH)O.Subsequently,Co(OH)O/Ti_(3)C_(2)(OH)_(x)MXene composites with metal-like conductiv-ity not only present spontaneous adsorption capacity of N_(2)H_(4),but also can modulated rate-determining step of dehydrogenation of∗N_(2)H_(4)to∗N_(2)H_(3)(0.54 eV)compared with Co(OH)O.Finally,the electrophilic oxygen of Co(OH)O/Ti_(3)C_(2)(OH)_(x)can spontaneously obtain electrons and protons from N_(2)H_(4),achieving the oxidation of N_(2)H_(4)while reducing Co(OH)O to Co(OH)_(2),thus completing the self-healing of the efficient catalyst.展开更多
The hydrazine oxidation-assisted hydrogen generation system significantly expands the applicability of hydrogen production technology.However,the complex intermediate transformations involved in the hydrazine oxidatio...The hydrazine oxidation-assisted hydrogen generation system significantly expands the applicability of hydrogen production technology.However,the complex intermediate transformations involved in the hydrazine oxidation reaction(HzOR)and hydrogen evolution reaction(HER)desperately need the development of dual-functional catalysts.Manipulating the d-band center of metal catalysts has been identified as one of the most effective approaches to enhance catalytic activity.Herein,Ir nanoparticles(NPs)anchored in B,N-codoped porous carbon(Ir@BNC)were developed and demonstrate excellent performances for both HER and HzOR in an alkaline medium,achieving 10 mA cm^(-2) at-25 and 18 mV,respectively.The overall hydrazine splitting(OHzS)electrolyzer reaches 200 mA cm^(-2) with a cell voltage of just 0.68 V.The direct liquid N2H4/H2O_(2) fuel cell(DHHPFC)assembly with Ir@BNC can achieve a maximum power density of 199.2 mW cm^(-2) at room temperature.Furthermore,an H2 production system using an OHzS device powered by DHHPFC realizes hydrogen production at a stable rate(53.08 mol h^(-1) m^(-2)).In-situ Raman tests and theoretical calculations unravel the metal-support interaction between Ir NPs and B,N-codoped porous carbon,optimizing the electronic structure and regulating the d-band center of Ir,reducing the adsorption energy of H*intermediates and N2H4 molecules,thus promoting the reaction processes of HER and HzOR.展开更多
Hydrogen production via electrochemical water splitting demands high working voltages(>1.23 V)and hence incurs high electricity costs,encumbering its large-scale applications.The development of more high-efficiency...Hydrogen production via electrochemical water splitting demands high working voltages(>1.23 V)and hence incurs high electricity costs,encumbering its large-scale applications.The development of more high-efficiency and electricity-saving systems for hydrogen production is of great significance.Hydrazine oxidation reaction(HzOR)-assisted hydrogen production technology,which is constructed by replacing the anodic oxygen evolution reaction in pure water electrolysis systems with the HzOR,can greatly reduce the working voltage and electricity consumption,and hence shows great application prospects.In recent years,numerous studies have focused on designing various bifunctional electrocatalysts to simultaneously catalyze the cathodic and anodic reactions in HzOR-assisted hydrogen production systems.However,comprehensive reviews summarizing and commenting on this field are scarce.This review provides a systematic and insightful overview of the developments in HzORassisted hydrogen production technology from 2017 to the present,primarily focusing on catalyst design strategies,catalytic mechanisms,and economic and application analysis.Additionally,this review discusses several challenges and outlines future research directions in this field to attract more researchers'attention and accelerate the research and potential applications of HzOR-assisted hydrogen production technology.展开更多
Seawater electrolysis could address the water scarcity issue and realize the grid-scale production of carbon-neutral hydrogen,while facing the challenge of high energy consumption and chloride corrosion.Thermodynamica...Seawater electrolysis could address the water scarcity issue and realize the grid-scale production of carbon-neutral hydrogen,while facing the challenge of high energy consumption and chloride corrosion.Thermodynamically more favorable hydrazine oxidation reaction(HzOR)assisted water electrolysis is efficiency for energy-saving and chlorine-free hydrogen production.Herein,the MoNi alloys supported on MoO_(2) nanorods with enlarged hollow diameter on Ni foam(MoNi@NF)are synthesized,which is constructed by limiting the outward diffusion of Ni via annealing and thermal reduction of NiMoO_(4) nanorods.When coupling HzOR and hydrogen evolution reaction(HER)by employing MoNi@NF as both anode and cathode in two-electrode seawater system,a low cell voltage of 0.54 V is required to achieve 1,000 mA·cm^(−2) and with long-term durability for 100 h to keep above 100 mA·cm^(−2) and nearly 100%Faradaic efficiency.It can save 2.94 W·h to generate per liter H_(2) relative to alkaline seawater electrolysis with 37%lower energy equivalent input.展开更多
Copper nanoparticles-decorated polyaniline- derived mesoporous carbon that can serve as noble metal-free electrocatalyst for the hydrazine oxidation reaction （HzOR） is synthesized via a facile synthetic route. The m...Copper nanoparticles-decorated polyaniline- derived mesoporous carbon that can serve as noble metal-free electrocatalyst for the hydrazine oxidation reaction （HzOR） is synthesized via a facile synthetic route. The material exhibits excellent electrocatalytic activity toward HzOR with low overpotential and high current density. The material also remains stable during the electrocatalytic reaction for long time. Its good electro- catalytic performance makes this material a promising alternative to conventional noble metal-based catalysts （e.g., Pt） that are commonly used in HzOR-based fuel cells.展开更多
Integrating hydrogen evolution reaction(HER)with hydrazine oxidation reaction(HzOR)has an encouraging prospect for the energy-saving hydrogen production,demanding the high-performance bifunctional HER/HzOR electrocata...Integrating hydrogen evolution reaction(HER)with hydrazine oxidation reaction(HzOR)has an encouraging prospect for the energy-saving hydrogen production,demanding the high-performance bifunctional HER/HzOR electrocatalyst.Ruthenium phosphide/doped carbon composites have exhibited superior activity towardmultiple electrocatalytic reactions.To explore the decent water-soluble precursors containing bothNand P elements is highly attractive to facilely prepare metal phosphide/doped carbon composites.Herein,as one kind ecofriendly biomolecules,adenine nucleotide was first employed to selectively fabricate the highly pure RuP nanoparticles embedded into porous N,P-codoped carbons(RuP/PNPC)with a straightforward“mix-and-pyrolyze”approach.The newly prepared RuP/PNPC only requires 4.0 and−83.0 mV at 10 mA/cm^(2) separately in alkaline HER and HzOR,outperforming most of reported electrocatalysts,together with the outstanding neutral bifunctional performance.Furthermore,the two-electrode alkaline and neutral overall hydrazine splitting both exhibit significant power-efficiency superiority to the corresponding overall water splitting with the voltage difference of larger than 2 V,which can be also easily driven by the fuel cells and solar cells with considerableH2 generation.Our report innovates the N-and P-bearing adenine nucleotide to effortlessly synthesize the high-quality RuP/doped carbon composite catalysts,highly potential as a universal platform for metal phosphide-related functional materials.展开更多
Developing high performance anode catalysts for oxygen evolution reaction (OER) and hydrazine oxidation reaction (HzOR) at large current density is an efficient pathway to produce hydrogen. Herein, we synthesize a FeW...Developing high performance anode catalysts for oxygen evolution reaction (OER) and hydrazine oxidation reaction (HzOR) at large current density is an efficient pathway to produce hydrogen. Herein, we synthesize a FeWO_(4)-WO_(3) heterostructure catalyst growing on nickel foam (FeWO_(4)-WO_(3)/NF) by a combination of hydrothermal and calcination method. It shows good catalytic activity with ultralow potentials for OER (ζ_(10) = 1.43 V, ζ_(1.000) = 1.56 V) and HzOR (ζ_(10) = −0.034 V, ζ_(1.000) = 0.164 V). Moreover, there is little performance degradation after being tested for _(10)0 h at 1,000 (OER) and _(10)0 (HzOR) mA·cm−2, indicating good stability. The superior performance could be attributed to the wolframite structure and heterostructure: The former provides a high electrical conductivity to ensure the electronic transfer capability, and the later induces interfacial electron redistribution to enhance the intrinsic activity and stability. The work offers a brand-new way to prepare good performance catalysts for OER and HzOR, especially at large current density.展开更多
The hydrazine oxidation reaction(HzOR)has garnered significant attention as a feasible approach to replace sluggish anodic reactions to save energy.Nevertheless,there are still difficulties in developing highly effici...The hydrazine oxidation reaction(HzOR)has garnered significant attention as a feasible approach to replace sluggish anodic reactions to save energy.Nevertheless,there are still difficulties in developing highly efficient catalysts for the HzOR.Herein,we report amorphous ruthenium nanosheets(a-Ru NSs)with a thickness of approximately 9.6 nm.As a superior bifunctional electrocatalyst,a-Ru NSs exhibited enhanced electrocatalytic performance toward both the HzOR and hydrogen evolution reaction(HER),outperforming benchmark Pt/C catalysts,where the a-Ru NSs achieved a work-ing potential of merely-76 mV and a low overpotential of only 17 mV to attain a current density of 10 mA·cm^(-2) for the HzOR and HER,respectively.Furthermore,a-Ru NSs displayed a low cell voltage of 28 mV at 10 mA·cm^(-2) for overall hy-drazine splitting in a two-electrode electrolyzer.In situ Raman spectra revealed that the a-Ru NSs can efficiently promote N‒N bond cleavage,thereby producing more*NH_(2)and accelerating the progress of the reaction.展开更多
Hydrazine-assisted water electrolysis presents a promising and efficient hydrogen production technology.However,developing high-performance hydrazine oxidation reaction(HzOR)and hydrogen evolution reaction(HER)bifunct...Hydrazine-assisted water electrolysis presents a promising and efficient hydrogen production technology.However,developing high-performance hydrazine oxidation reaction(HzOR)and hydrogen evolution reaction(HER)bifunctional catalysts remains challenging.Here,we report a bifunctional electrocatalyst of Ru NCs@NPC,embedding the ultrafine Ru nanoclusters into N-doped porous carbon via microwave reduction.Due to the ultrafine Ru nanoclusters and N doping,the composite exhibits exceptional activity for both HER and HzOR,requiring−55 and−67 mV to reach 10 mA·cm^(−2) in alkaline media.In the overall hydrazine splitting(OHzS)system,Ru NCs@NPC is used as both anode and cathode materials,achieving 10 mA·cm^(−2) only at 0.036 V.The zinc hydrazine(Zn-Hz)battery assembled with Ru NCs@NPC cathode and Zn foil anode can provide a stable voltage of 0.4 V and exhibit 98.5%energy efficiency.Therefore,integrating Zn-Hz battery with OHzS system enables self-powered H_(2) evolution.The density function theory calculations reveal that the Ru-N bond increases the metal-support interaction.展开更多
Sustainable H_(2) production based on hydrogen evolution reaction (HER) and hydrazine oxidation reaction (HzOR) has attracted wide attention due to minimal energy consumption compared to overall water electrolysis.The...Sustainable H_(2) production based on hydrogen evolution reaction (HER) and hydrazine oxidation reaction (HzOR) has attracted wide attention due to minimal energy consumption compared to overall water electrolysis.The present study focuses on the design and construction of heterostructured CoPB@NiFe-OH applied as efficient bifunctional catalysts to sustainably produce hydrogen and remove hydrazine in alkaline media.Impressively,CoPB@NiFe-OH heterointerface exhibits an HzOR potential of-135 mV at the current density of 10 mA cm^(2) when the P to B atom ratio was 0.2,simultaneously an HER potential of-32 mV toward HER when the atom ratio of P and B was 0.5.Thus,hydrogen production without an outer voltage accompanied by a small current density output of 25 mA cm^(2) is achieved,surpassing most reported catalysts.In addition,DFT calculations demonstrate the Co sites in CoPB upgrades H*adsorption,while the Ni sites in NiFe-OH optimizes the adsorption energy of N_(2)H_(4)*due to electron transfer from CoPB to NiFe-OH at the heterointerface,ultimately leading to exceptional performance in hydrazine-assistant water electrolysis via HER coupled with HzOR.展开更多
Zn-CO_(2)batteries(ZCBs)are promising for CO_(2)conversion and electric energy release.However,the ZCBs couple the electrochemical CO_(2)reduction(ECO_(2)R)with the oxygen evolution reaction and competitive hydrogen e...Zn-CO_(2)batteries(ZCBs)are promising for CO_(2)conversion and electric energy release.However,the ZCBs couple the electrochemical CO_(2)reduction(ECO_(2)R)with the oxygen evolution reaction and competitive hydrogen evolution reaction,which normally causes ultrahigh charge voltage and CO_(2)conversion efficiency attenuation,thereby resulting in~90%total power consumption.Herein,isolated FeN_(3)sites encapsulated in hierarchical porous carbon nanoboxes(Fe-HPCN,derived from the thermal activation process of ferrocene and polydopamine-coated cubic ZIF-8)were proposed for hydrazine-assisted rechargeable ZCBs based on ECO_(2)R(discharging process:CO_(2)+2H+→CO+H_(2)O)and hydrazine oxidation reaction(HzOR,charging process:N_(2)H_(4)+4OH−→N_(2)+4H_(2)O+4e^(−)).The isolated FeN_(3)endows the HzOR with a lower overpotential and boosts the ECO_(2)R with a 96%CO Faraday efficiency(FECO).Benefitting from the bifunctional ECO_(2)R and HzOR catalytic activities,the homemade hydrazine-assisted rechargeable ZCBs assembled with the Fe-HPCN air cathode exhibited an ultralow charge voltage(decreasing by~1.84 V),excellent CO selectivity(FECO close to 100%),and high 89%energy efficiency.In situ infrared spectroscopy confirmed that Fe-HPCN can generate rate-determining*N_(2)and*CO intermediates during HzOR and ECO_(2)R.This paper proposes FeN_(3)centers for bifunctional ECO_(2)R/HzOR performance and further presents the pioneering achievements of ECO_(2)R and HzOR for hydrazine-assisted rechargeable ZCBs.展开更多
Hydrazine-assisted water electrolysis is a promising energy conversion technology for highly efficient hydrogen production.Rational design of bifunctional electrocatalysts,which can simultaneously accelerate hydrogen ...Hydrazine-assisted water electrolysis is a promising energy conversion technology for highly efficient hydrogen production.Rational design of bifunctional electrocatalysts,which can simultaneously accelerate hydrogen evolution reaction(HER)/hydrazine oxidation reaction(HzOR)kinetics,is the key step.Herein,we demonstrate the development of ultrathin P/Fe co-doped NiSe_(2) nanosheets supported on modified Ni foam(P/Fe-NiSe_(2)) synthesized through a facile electrodeposition process and subsequent heat treatment.Based on electrochemical measurements,characterizations,and density functional theory calculations,a favorable“2+2”reaction mechanism with a two-step HER process and a two-step HzOR step was fully proved and the specific effect of P doping on HzOR kinetics was investigated.P/Fe-NiSe_(2) thus yields an impressive electrocatalytic performance,delivering a high current density of 100 mA cm^(−2) with potentials of−168 and 200 mV for HER and HzOR,respectively.Additionally,P/Fe-NiSe_(2) can work efficiently for hydrazine-assisted water electrolysis and Zn-Hydrazine(Zn-Hz)battery,making it promising for practical application.展开更多
Utilizing the hydrazine-assisted water electrolysis for energy-efficient hydrogen production shows a promising application, which relies on the development and design of efficient bifunctional electrocatalysts. Herein...Utilizing the hydrazine-assisted water electrolysis for energy-efficient hydrogen production shows a promising application, which relies on the development and design of efficient bifunctional electrocatalysts. Herein, we reported a low-content Pt-doped Rh metallene(Pt-Rhene) for hydrazine-assisted water electrolysis towards energy-saving hydrogen(H_(2)) production, where the ultrathin metallene is constructed to provide enough favorable active sites for catalysis and improve atom utilization.Additionally, the synergistic effect between Rh and Pt can optimize the electronic structure of Rh for improving the intrinsic activity. Therefore, the required overpotential of Pt-Rhene is only 37 mV to reach a current density of-10 mA cm^(-2) in the hydrogen evolution reaction(HER), and the Pt-Rhene exhibits a required overpotential of only 11 mV to reach a current density of 10 mA cm^(-2) in the hydrazine oxidation reaction(HzOR). With the constructed HER-HzOR two-electrode system, the Pt-Rhene electrodes exhibit an extremely low voltage(0.06/0.19/0.28 V) to achieve current densities of 10/50/100 mA cm^(-2) for energy-saving H_(2) production, which greatly reduces the electrolysis energy consumption. Moreover,DFT calculations further demonstrate that the introduction of Pt modulates the electronic structure of Rh and optimizes the d-band center, thus enhancing the adsorption and desorption of reactant/intermediates in the electrocatalytic reaction.展开更多
Cu nanocrystals(NCs)are considered an important kind of material for practical application,however their enhancement of photo-electronic catalysis is less reported owing to their lower activity and large overpotential...Cu nanocrystals(NCs)are considered an important kind of material for practical application,however their enhancement of photo-electronic catalysis is less reported owing to their lower activity and large overpotential.Herein,a C_(3)N_(4)/Cu hetero-structure was prepared for studying the photo-electronic catalysis of hydrazine oxidation and redox reactions of methyl orange and ammonium formate.Cu NC enhancement of absorption and photo-electronic catalysis was proved,which provides the possibility of wider applications of Cu NCs.展开更多
Energy-efficient electrolytic hydrogen generation is highly desired but still remains challenging.In this work,we demonstrate that a Cu_(3)P nanoarray on copper foam(Cu_(3)P/CF)behaves as a high-performance electrocat...Energy-efficient electrolytic hydrogen generation is highly desired but still remains challenging.In this work,we demonstrate that a Cu_(3)P nanoarray on copper foam(Cu_(3)P/CF)behaves as a high-performance electrocatalyst for hydrazine oxidation reaction(HzOR)in alkaline electrolytes.A full electrolytic system employing Cu_(3)P/CF as both an anode for HzOR and a cathode for hydrogen evolution reaction drives 100 mA cm^(-2)at a voltage of 0.72 V in 1.0 M KOH aqueous solution with 0.5 M hydrazine.It also demonstrates high long-term stability.展开更多
Co-based spinel oxides with unique crystal structures have been identified as a class of promising candidates for alkaline water oxidation catalysis in oxide structural families.Unfortunately,their relatively poor con...Co-based spinel oxides with unique crystal structures have been identified as a class of promising candidates for alkaline water oxidation catalysis in oxide structural families.Unfortunately,their relatively poor conductivity exerts significant negative impacts on efficient charge transfer,thereby inhibiting the enhancement of their intrinsic activity for electrochemical water splitting.Optimizing the electronic structure of the catalytically active sites of Co-based spinel oxide electrocatalysts is of great significance for improving the electrocatalytic performance.Herein,a facile heterometal doping strategy is reported to synthesize an oxygen-vacancy-rich Ru-doped Co_(3)O_(4) nanosheet array on a cobalt foam substrate(denoted as Ru-Co_(3)O_(4)|VO/CF)as a trifunctional catalyst for significantly boosting the hydrogen evolution reaction(HER),oxygen evolution reaction(OER)and hydrazine oxidation reaction(HzOR)electrocatalytic activities,which involves the electrodeposition process,cation exchange approach,and subsequent thermal oxidation treatment.Benefiting from the 3D hierarchical structural merits and more exposed active sites caused by local Jahn-Teller distortions,the optimized catalyst exhibits excellent catalytic performance towards the HER and OER,affording a current density of 100 mA cm^(-2) at low overpotentials of 48.6 and 270 mV in 1 M KOH,respectively,along with remarkable stability and durability.Interestingly,the integrated Ru-Co_(3)O_(4)|VO/CF water electrolyzer only requires a low cell voltage of 1.47 V to reach 10 mA cm^(-2),outperforming the benchmark couple of the Pt/C(−)||RuO2(+)electrode and most reported counterparts.More impressively,a hydrazine-assisted water electrolysis electrolyzer is subsequently assembled by using Ru-Co_(3)O_(4)|VO/CF electrodes,delivering a current density of 100 mA cm^(-2) with an ultralow operating voltage of 0.70 V,which is 1.1 V lower than that of its hydrazine free counterpart.Density functional theory results reveal that the synergistic effect of Ru doping and oxygen vacancies could effectively modify the spin configuration(eg orbital occupancy),tune the d-band center of Co ions and optimize the Gibbs free energy of hydrogen adsorption and the adsorption energy of OER intermediates,consequently resulting in the enhancement of the intrinsic catalytic activity of Co_(3)O_(4).This work provides important referential value for fabricating highly efficient and stable catalysts towards sustainable energy conversion and storage.展开更多
Molybdenum phosphides(MoP)are emerging as an attractive catalyst for water splitting due to their excellent activity and stability.However,most of the MoP synthesized so far are crystalline MoP with relatively fewer e...Molybdenum phosphides(MoP)are emerging as an attractive catalyst for water splitting due to their excellent activity and stability.However,most of the MoP synthesized so far are crystalline MoP with relatively fewer exposed active sites and low electrical conductivity.Here,we use a metallo-organic Mo precursor(MoO_(2)(acac)_(2))to create defect-rich crystalline MoP nanoparticles and uniformly anchor them on reduced graphene oxide(denoted as D-MoP/rGO).High-temperature thermal decomposition of the precursor generates gases,which induce a variety of defects in D-MoP/rGO along with a P-rich surface composition.The electrochemically active surface area of D-MoP/rGO is 8 times that of bulk MoP.D-MoP/rGO requires a small overpotential of 122 mV for the hydrogen evolution reaction(HER)to reach a current density of 10 mA cm^(-2).Furthermore,density functional theory(DFT)calculation results reveal that surface P sites are the key active sites,which favor the adsorption of H atoms and also act as an H deliverer to promote the HER.Importantly,D-MoP/rGO is also a highly active catalyst for the hydrazine oxidation reaction(HzOR)and requires a low overpotential of 84 mV to reach a current density of 10 mA cm^(-2).Thus,efficient HER||HzOR hybrid water-splitting can be realized using D-MoP/rGO,which can deliver a current density of 100 mA cm^(-2)at a small cell voltage of 0.74 V and undergo a stable 12 h operation.In summary,a simple method has been demonstrated to generate high-performance metal phosphide electrocatalysts for total water splitting.Furthermore,the material design concept of creating defective crystalline nanoparticles using gas generating metal precursors can serve as a general approach to create various catalytic active defective crystalline materials.展开更多
基金supported by a National Research Foundation of Korea(NRF)grant funded by the Korean government(MSIT)(No.RS-2024-00335976)。
文摘The performance of hematite(α-Fe_(2)O_(3))photoanodes for photoelectrochemical(PEC)water splitting has been limited to around 2-5 mA cm^(-2)under standard conditions due to their short hole diffusion length and sluggish oxygen evolution reaction kinetics.This work overcomes those challenges through a synergistic strategy that co-designs the hematite architecture and the surface reaction pathway.We introduce a textured and hierarchically porous Ti-doped Fe_(2)O_(3)(tp-Fe_(2)O_(3))photoanode,synthesized via multi-cycle growth and flame annealing method.This unique architecture features a high texture(110),enlarged surface area,and hierarchically porous structure,which enable significantly enhanced bulk charge transport and interfacial charge transfer compared to typical nanorod Ti-doped Fe_(2)O_(3)(nr-Fe_(2)O_(3)).As a result,the tp-Fe_(2)O_(3)photoanode achieves a photocurrent density of 3.1 mA cm^(-2)at 1.23 V vs.RHE with exceptional stability over 105 h,notably without any co-catalyst.By replacing the OER with the hydrazine oxidation reaction,the photocurrent further reaches a record-high level of 7.1 mA cm^(-2)at 1.23 V_(RHE).Finally,when we integrate the tp-Fe_(2)O_(3)with a commercial Si solar cell,it achieves a solar-to-hydrogen efficiency of 8.7%-the highest reported value for any Fe_(2)O_(3)-based PVtandem system.This work provides critical insights into rational Fe_(2)O_(3)photoanode design and highlights the potential of hydrazine as an efficient alternative anodic reaction,enabling waste valorization.
基金supported by the National Natural Science Foundation of China(No.20876038)the Scientific Research Fund of Hunan Provincial Education Department,China(No.07A019)the Scientific Research Foundation for Returned Overseas Chinese Scholars of the Ministry of Education of China(No.[2007]1108)
文摘From an aqueous mixture of Ag(I)-EDTA complex and Ni(II)nitrate,silver and nickel particles were co-deposited on the surface of titanium substrates by the hydrothermal method using hydrazine hydrate as a reduction agent.The prepared titanium-supported nano-scale Ag and Ag-Ni particles(nano Ag/Ti,nano Ag86Ni14/Ti,nano Ag77Ni23/Ti,and nano Ag74Ni26/Ti)exhibit nanoporous 3D network textures.Their electrocatalytic activity towards hydrazine oxidation in alkaline solutions was evaluated by cyclic voltammetry and chronoamperometry.The results show that the four samples present a low onset potential of ca.-0.60 V vs.SCE and considerably high and stable anodic current densities for hydrazine oxidation.Among them,the nano Ag86Ni14/Ti electrode exhibits the highest anodic current density towards hydrazine oxidation,showing an increment of electro-active sites on the nano Ag86Ni14/Ti due to the addition of Ni to Ag particles.
基金financially supported by the Nation Natural Science Foundation of China(No.21475118)
文摘A hydrogen evolution-assisted one-pot aqueous approach was developed for facile synthesis of trimetallic Pd Ni Ru alloy nanochain-like networks（Pd Ni Ru NCNs） by only using KBHas the reductant, without any specific additive（e.g. surfactant, polymer, template or seed）. The products were mainly investigated by transmission electron microscopy（TEM）, X-ray diffraction（XRD） and X-ray photoelectron spectroscopy（XPS）. The hierarchical architectures were formed by the oriented assembly growth and the diffusioncontrolled deposition in the presence of many in-situ generated hydrogen bubbles. The architectures had the largest electrochemically active surface area（ECSA） of 84.32 mgPdthan Pd Ni nanoparticles(NPs,65.23 mgPd), Pd Ru NPs(23.12 mgPd), Ni Ru NPs（nearly zero）, and commercial Pd black(6.01 mgPd), outperforming the referenced catalysts regarding the catalytic characters for hydrazine oxygen reaction（HOR）. The synthetic route provides new insight into the preparation of other trimetallic nanocatalysts in fuel cells.
基金supported by the National Natural Science Foundation of China(Nos.62004143 and 22174033)the Key R&D Program of Hubei Province(No.2022BAA084)the Knowledge Innovation Program of Wuhan-Shuguang Project(No.2022010801020355).
文摘The development of efficient hydrazine oxidation reaction(HzOR)catalysts is important for the construc-tion of remarkable energy storage and conversion systems.However,after a period of electrochemical reaction,the active site of the catalyst will be irreversibly reduced or inactivated,and how to recover the active site is a major challenge.Here,we report 2D Co(OH)_(2)/Ti_(3)C_(2)(OH)_(x)MXene composites with rapid re-construction and self-healing behaviors as efficient and stable electrocatalysts during HzOR process.Both experimental and theoretical results indicate that the introduction of Ti_(3)C_(2)(OH)_(x)MXene can effectively reduce the dehydrogenation barrier of Co(OH)_(2),from 0.584 eV to 0.481 eV to form the real catalytic active center Co(OH)O.Subsequently,Co(OH)O/Ti_(3)C_(2)(OH)_(x)MXene composites with metal-like conductiv-ity not only present spontaneous adsorption capacity of N_(2)H_(4),but also can modulated rate-determining step of dehydrogenation of∗N_(2)H_(4)to∗N_(2)H_(3)(0.54 eV)compared with Co(OH)O.Finally,the electrophilic oxygen of Co(OH)O/Ti_(3)C_(2)(OH)_(x)can spontaneously obtain electrons and protons from N_(2)H_(4),achieving the oxidation of N_(2)H_(4)while reducing Co(OH)O to Co(OH)_(2),thus completing the self-healing of the efficient catalyst.
基金financially supported by the National Natural Science Foundation of China(52371222,52271211,52303341)the Natural Science Foundation of Hunan Province in China(2025JJ60350,2023JJ50043)+1 种基金Key Research and Development Program of Hunan Province(2023GK2035)HORIZON EUROPE Marie Sklodowska-Curie Actions-2021(101065098)。
文摘The hydrazine oxidation-assisted hydrogen generation system significantly expands the applicability of hydrogen production technology.However,the complex intermediate transformations involved in the hydrazine oxidation reaction(HzOR)and hydrogen evolution reaction(HER)desperately need the development of dual-functional catalysts.Manipulating the d-band center of metal catalysts has been identified as one of the most effective approaches to enhance catalytic activity.Herein,Ir nanoparticles(NPs)anchored in B,N-codoped porous carbon(Ir@BNC)were developed and demonstrate excellent performances for both HER and HzOR in an alkaline medium,achieving 10 mA cm^(-2) at-25 and 18 mV,respectively.The overall hydrazine splitting(OHzS)electrolyzer reaches 200 mA cm^(-2) with a cell voltage of just 0.68 V.The direct liquid N2H4/H2O_(2) fuel cell(DHHPFC)assembly with Ir@BNC can achieve a maximum power density of 199.2 mW cm^(-2) at room temperature.Furthermore,an H2 production system using an OHzS device powered by DHHPFC realizes hydrogen production at a stable rate(53.08 mol h^(-1) m^(-2)).In-situ Raman tests and theoretical calculations unravel the metal-support interaction between Ir NPs and B,N-codoped porous carbon,optimizing the electronic structure and regulating the d-band center of Ir,reducing the adsorption energy of H*intermediates and N2H4 molecules,thus promoting the reaction processes of HER and HzOR.
基金supported by National Natural Science Foundation of China(Grant Nos.52301259 and 22208019)the Beijing Institute of Technology Research Fund Program for Young Scholars。
文摘Hydrogen production via electrochemical water splitting demands high working voltages(>1.23 V)and hence incurs high electricity costs,encumbering its large-scale applications.The development of more high-efficiency and electricity-saving systems for hydrogen production is of great significance.Hydrazine oxidation reaction(HzOR)-assisted hydrogen production technology,which is constructed by replacing the anodic oxygen evolution reaction in pure water electrolysis systems with the HzOR,can greatly reduce the working voltage and electricity consumption,and hence shows great application prospects.In recent years,numerous studies have focused on designing various bifunctional electrocatalysts to simultaneously catalyze the cathodic and anodic reactions in HzOR-assisted hydrogen production systems.However,comprehensive reviews summarizing and commenting on this field are scarce.This review provides a systematic and insightful overview of the developments in HzORassisted hydrogen production technology from 2017 to the present,primarily focusing on catalyst design strategies,catalytic mechanisms,and economic and application analysis.Additionally,this review discusses several challenges and outlines future research directions in this field to attract more researchers'attention and accelerate the research and potential applications of HzOR-assisted hydrogen production technology.
基金supported by the National Natural Science Foundation of China(Nos.51772162 and 52072197)the Outstanding Youth Foundation of Shandong Province,China(No.ZR2019JQ14)+3 种基金the Youth Innovation and Technology Foundation of Shandong Higher Education Institutions,China(No.2019KJC004)the Major Scientific and Technological Innovation Project(No.2019JZZY020405)the Major Basic Research Program of Natural Science Foundation of Shandong Province(No.ZR2020ZD09)the Taishan Scholar Young Talent Program(No.tsqn201909114).
文摘Seawater electrolysis could address the water scarcity issue and realize the grid-scale production of carbon-neutral hydrogen,while facing the challenge of high energy consumption and chloride corrosion.Thermodynamically more favorable hydrazine oxidation reaction(HzOR)assisted water electrolysis is efficiency for energy-saving and chlorine-free hydrogen production.Herein,the MoNi alloys supported on MoO_(2) nanorods with enlarged hollow diameter on Ni foam(MoNi@NF)are synthesized,which is constructed by limiting the outward diffusion of Ni via annealing and thermal reduction of NiMoO_(4) nanorods.When coupling HzOR and hydrogen evolution reaction(HER)by employing MoNi@NF as both anode and cathode in two-electrode seawater system,a low cell voltage of 0.54 V is required to achieve 1,000 mA·cm^(−2) and with long-term durability for 100 h to keep above 100 mA·cm^(−2) and nearly 100%Faradaic efficiency.It can save 2.94 W·h to generate per liter H_(2) relative to alkaline seawater electrolysis with 37%lower energy equivalent input.
文摘Copper nanoparticles-decorated polyaniline- derived mesoporous carbon that can serve as noble metal-free electrocatalyst for the hydrazine oxidation reaction （HzOR） is synthesized via a facile synthetic route. The material exhibits excellent electrocatalytic activity toward HzOR with low overpotential and high current density. The material also remains stable during the electrocatalytic reaction for long time. Its good electro- catalytic performance makes this material a promising alternative to conventional noble metal-based catalysts （e.g., Pt） that are commonly used in HzOR-based fuel cells.
基金Development Project of Youth Innovation Team in Shandong Colleges and Universities,Grant/Award Number:2019KJC031Natural Science Foundation of Shandong Province,Grant/Award Numbers:ZR2019MB064,ZR2021MB122Doctoral Program of Liaocheng University,Grant/Award Number:318051608。
文摘Integrating hydrogen evolution reaction(HER)with hydrazine oxidation reaction(HzOR)has an encouraging prospect for the energy-saving hydrogen production,demanding the high-performance bifunctional HER/HzOR electrocatalyst.Ruthenium phosphide/doped carbon composites have exhibited superior activity towardmultiple electrocatalytic reactions.To explore the decent water-soluble precursors containing bothNand P elements is highly attractive to facilely prepare metal phosphide/doped carbon composites.Herein,as one kind ecofriendly biomolecules,adenine nucleotide was first employed to selectively fabricate the highly pure RuP nanoparticles embedded into porous N,P-codoped carbons(RuP/PNPC)with a straightforward“mix-and-pyrolyze”approach.The newly prepared RuP/PNPC only requires 4.0 and−83.0 mV at 10 mA/cm^(2) separately in alkaline HER and HzOR,outperforming most of reported electrocatalysts,together with the outstanding neutral bifunctional performance.Furthermore,the two-electrode alkaline and neutral overall hydrazine splitting both exhibit significant power-efficiency superiority to the corresponding overall water splitting with the voltage difference of larger than 2 V,which can be also easily driven by the fuel cells and solar cells with considerableH2 generation.Our report innovates the N-and P-bearing adenine nucleotide to effortlessly synthesize the high-quality RuP/doped carbon composite catalysts,highly potential as a universal platform for metal phosphide-related functional materials.
基金This work is supported by the National Natural Science Foundation of China(No.21872040)the Hundred Talents Program of Guangxi Universities,the Excellent Scholars and Innovation Team of Guangxi Universities,Guangxi Major Projects of Science and Technology(No.GXMPSTAA17202032),Guangxi Ba-Gui Scholars Program.
文摘Developing high performance anode catalysts for oxygen evolution reaction (OER) and hydrazine oxidation reaction (HzOR) at large current density is an efficient pathway to produce hydrogen. Herein, we synthesize a FeWO_(4)-WO_(3) heterostructure catalyst growing on nickel foam (FeWO_(4)-WO_(3)/NF) by a combination of hydrothermal and calcination method. It shows good catalytic activity with ultralow potentials for OER (ζ_(10) = 1.43 V, ζ_(1.000) = 1.56 V) and HzOR (ζ_(10) = −0.034 V, ζ_(1.000) = 0.164 V). Moreover, there is little performance degradation after being tested for _(10)0 h at 1,000 (OER) and _(10)0 (HzOR) mA·cm−2, indicating good stability. The superior performance could be attributed to the wolframite structure and heterostructure: The former provides a high electrical conductivity to ensure the electronic transfer capability, and the later induces interfacial electron redistribution to enhance the intrinsic activity and stability. The work offers a brand-new way to prepare good performance catalysts for OER and HzOR, especially at large current density.
基金supported by the National Key R&D Program of China(2018YFA0702001)National Natural Science Foundation of China(22371268,22301287)+3 种基金Fundamental Research Funds for the Central Universities(WK2060000016)Anhui Provincial Natural Science Foundation(2208085J09,2208085QB33)Collaborative Innovation Program of Hefei Science Center,CAS(2022HSC-CIP020)Youth Innovation Promotion Association of the Chinese Academy of Science(2018494)and USTC Tang Scholar.
文摘The hydrazine oxidation reaction(HzOR)has garnered significant attention as a feasible approach to replace sluggish anodic reactions to save energy.Nevertheless,there are still difficulties in developing highly efficient catalysts for the HzOR.Herein,we report amorphous ruthenium nanosheets(a-Ru NSs)with a thickness of approximately 9.6 nm.As a superior bifunctional electrocatalyst,a-Ru NSs exhibited enhanced electrocatalytic performance toward both the HzOR and hydrogen evolution reaction(HER),outperforming benchmark Pt/C catalysts,where the a-Ru NSs achieved a work-ing potential of merely-76 mV and a low overpotential of only 17 mV to attain a current density of 10 mA·cm^(-2) for the HzOR and HER,respectively.Furthermore,a-Ru NSs displayed a low cell voltage of 28 mV at 10 mA·cm^(-2) for overall hy-drazine splitting in a two-electrode electrolyzer.In situ Raman spectra revealed that the a-Ru NSs can efficiently promote N‒N bond cleavage,thereby producing more*NH_(2)and accelerating the progress of the reaction.
基金supported by the National Natural Science Foundation of China(Nos.52371222 and 52271211)the Natural Science Foundation of Hunan Province in China(Nos.2024JJ4022,2023JJ30277 and 2023JJ50043)+1 种基金the Science and Technology Innovation Program of Hunan Province(No.2023RC3185),ChinaHORIZON-Marie Skłodowska-Curie Actions-2021-PF(No.101065098),European Union.
文摘Hydrazine-assisted water electrolysis presents a promising and efficient hydrogen production technology.However,developing high-performance hydrazine oxidation reaction(HzOR)and hydrogen evolution reaction(HER)bifunctional catalysts remains challenging.Here,we report a bifunctional electrocatalyst of Ru NCs@NPC,embedding the ultrafine Ru nanoclusters into N-doped porous carbon via microwave reduction.Due to the ultrafine Ru nanoclusters and N doping,the composite exhibits exceptional activity for both HER and HzOR,requiring−55 and−67 mV to reach 10 mA·cm^(−2) in alkaline media.In the overall hydrazine splitting(OHzS)system,Ru NCs@NPC is used as both anode and cathode materials,achieving 10 mA·cm^(−2) only at 0.036 V.The zinc hydrazine(Zn-Hz)battery assembled with Ru NCs@NPC cathode and Zn foil anode can provide a stable voltage of 0.4 V and exhibit 98.5%energy efficiency.Therefore,integrating Zn-Hz battery with OHzS system enables self-powered H_(2) evolution.The density function theory calculations reveal that the Ru-N bond increases the metal-support interaction.
基金the Department of Science and Technology of Anhui Province(2022h11020024)Anhui Construction Engineering Group Co.,Ltd.(SG2025Q11)+4 种基金Basic Research Project from Institute of Coal Chemistry,CAS(SCJC-HN-2022-17)Shanxi Province Science Foundation(20210302124446202102070301018)The University Synergy Innovation Program of Anhui Province(GXXT-2022-27)Scientific Research Foundation for High-level Talents of Anhui University of Science and Technology(2023yjrc51)for funding。
文摘Sustainable H_(2) production based on hydrogen evolution reaction (HER) and hydrazine oxidation reaction (HzOR) has attracted wide attention due to minimal energy consumption compared to overall water electrolysis.The present study focuses on the design and construction of heterostructured CoPB@NiFe-OH applied as efficient bifunctional catalysts to sustainably produce hydrogen and remove hydrazine in alkaline media.Impressively,CoPB@NiFe-OH heterointerface exhibits an HzOR potential of-135 mV at the current density of 10 mA cm^(2) when the P to B atom ratio was 0.2,simultaneously an HER potential of-32 mV toward HER when the atom ratio of P and B was 0.5.Thus,hydrogen production without an outer voltage accompanied by a small current density output of 25 mA cm^(2) is achieved,surpassing most reported catalysts.In addition,DFT calculations demonstrate the Co sites in CoPB upgrades H*adsorption,while the Ni sites in NiFe-OH optimizes the adsorption energy of N_(2)H_(4)*due to electron transfer from CoPB to NiFe-OH at the heterointerface,ultimately leading to exceptional performance in hydrazine-assistant water electrolysis via HER coupled with HzOR.
基金National Natural Science Foundation of China,Grant/Award Number:12274118Double First Class University Plan,Grant/Award Number:C176220100042+2 种基金National Natural Science Foundation of China-Yunnan Joint Fund,Grant/Award Number:U2002213Open Foundation of Guangxi Key Laboratory of Processing for Non-Ferrous Metals and Featured Materials,Grant/Award Number:2022GXYSOF10Henan Center for Outstanding Overseas Scientists,Grant/Award Number:GZS2023007.
文摘Zn-CO_(2)batteries(ZCBs)are promising for CO_(2)conversion and electric energy release.However,the ZCBs couple the electrochemical CO_(2)reduction(ECO_(2)R)with the oxygen evolution reaction and competitive hydrogen evolution reaction,which normally causes ultrahigh charge voltage and CO_(2)conversion efficiency attenuation,thereby resulting in~90%total power consumption.Herein,isolated FeN_(3)sites encapsulated in hierarchical porous carbon nanoboxes(Fe-HPCN,derived from the thermal activation process of ferrocene and polydopamine-coated cubic ZIF-8)were proposed for hydrazine-assisted rechargeable ZCBs based on ECO_(2)R(discharging process:CO_(2)+2H+→CO+H_(2)O)and hydrazine oxidation reaction(HzOR,charging process:N_(2)H_(4)+4OH−→N_(2)+4H_(2)O+4e^(−)).The isolated FeN_(3)endows the HzOR with a lower overpotential and boosts the ECO_(2)R with a 96%CO Faraday efficiency(FECO).Benefitting from the bifunctional ECO_(2)R and HzOR catalytic activities,the homemade hydrazine-assisted rechargeable ZCBs assembled with the Fe-HPCN air cathode exhibited an ultralow charge voltage(decreasing by~1.84 V),excellent CO selectivity(FECO close to 100%),and high 89%energy efficiency.In situ infrared spectroscopy confirmed that Fe-HPCN can generate rate-determining*N_(2)and*CO intermediates during HzOR and ECO_(2)R.This paper proposes FeN_(3)centers for bifunctional ECO_(2)R/HzOR performance and further presents the pioneering achievements of ECO_(2)R and HzOR for hydrazine-assisted rechargeable ZCBs.
基金supported by the National Natural Science Foundation of China(22179065,22111530112,21875118)the Tianjin Graduate Research and Innovation Project(2022BKY018)the Ph.D.Candidate Research Innovation Fund of NKU School of Materials Science and Engineering.
文摘Hydrazine-assisted water electrolysis is a promising energy conversion technology for highly efficient hydrogen production.Rational design of bifunctional electrocatalysts,which can simultaneously accelerate hydrogen evolution reaction(HER)/hydrazine oxidation reaction(HzOR)kinetics,is the key step.Herein,we demonstrate the development of ultrathin P/Fe co-doped NiSe_(2) nanosheets supported on modified Ni foam(P/Fe-NiSe_(2)) synthesized through a facile electrodeposition process and subsequent heat treatment.Based on electrochemical measurements,characterizations,and density functional theory calculations,a favorable“2+2”reaction mechanism with a two-step HER process and a two-step HzOR step was fully proved and the specific effect of P doping on HzOR kinetics was investigated.P/Fe-NiSe_(2) thus yields an impressive electrocatalytic performance,delivering a high current density of 100 mA cm^(−2) with potentials of−168 and 200 mV for HER and HzOR,respectively.Additionally,P/Fe-NiSe_(2) can work efficiently for hydrazine-assisted water electrolysis and Zn-Hydrazine(Zn-Hz)battery,making it promising for practical application.
基金financially supported by the National Natural Science Foundation of China (No. 21972126, 21978264, 21905250, and 22278369)the Natural Science Foundation of Zhejiang Province (No. LQ22B030012 and LQ23B030010)the China Postdoctoral Science Foundation (2021M702889)。
文摘Utilizing the hydrazine-assisted water electrolysis for energy-efficient hydrogen production shows a promising application, which relies on the development and design of efficient bifunctional electrocatalysts. Herein, we reported a low-content Pt-doped Rh metallene(Pt-Rhene) for hydrazine-assisted water electrolysis towards energy-saving hydrogen(H_(2)) production, where the ultrathin metallene is constructed to provide enough favorable active sites for catalysis and improve atom utilization.Additionally, the synergistic effect between Rh and Pt can optimize the electronic structure of Rh for improving the intrinsic activity. Therefore, the required overpotential of Pt-Rhene is only 37 mV to reach a current density of-10 mA cm^(-2) in the hydrogen evolution reaction(HER), and the Pt-Rhene exhibits a required overpotential of only 11 mV to reach a current density of 10 mA cm^(-2) in the hydrazine oxidation reaction(HzOR). With the constructed HER-HzOR two-electrode system, the Pt-Rhene electrodes exhibit an extremely low voltage(0.06/0.19/0.28 V) to achieve current densities of 10/50/100 mA cm^(-2) for energy-saving H_(2) production, which greatly reduces the electrolysis energy consumption. Moreover,DFT calculations further demonstrate that the introduction of Pt modulates the electronic structure of Rh and optimizes the d-band center, thus enhancing the adsorption and desorption of reactant/intermediates in the electrocatalytic reaction.
基金supported by a General Financial Grant from the China Postdoctoral Science Foundation(2017M622787)National Natural Science Foundation of China(51673117,51702016,51631001,51602143)+4 种基金Guangdong Natural Science Fund for Distinguished Young Scholars(2016A030306020)Guangdong Youth Talent Plan(2015TQ01C536)Shenzhen Peacock Plan(KQCX20140521161756228)Shenzhen Special Fund for the Development of Emerging Industries(JCYJ20140417115840233)the Science and Technology Innovation Commission of Shenzhen(JCYJ20150529164656097,JSGG20160226201833790,JCYJ20170818093832350).
文摘Cu nanocrystals(NCs)are considered an important kind of material for practical application,however their enhancement of photo-electronic catalysis is less reported owing to their lower activity and large overpotential.Herein,a C_(3)N_(4)/Cu hetero-structure was prepared for studying the photo-electronic catalysis of hydrazine oxidation and redox reactions of methyl orange and ammonium formate.Cu NC enhancement of absorption and photo-electronic catalysis was proved,which provides the possibility of wider applications of Cu NCs.
基金National Natural Science Foundation of China(21575137)。
文摘Energy-efficient electrolytic hydrogen generation is highly desired but still remains challenging.In this work,we demonstrate that a Cu_(3)P nanoarray on copper foam(Cu_(3)P/CF)behaves as a high-performance electrocatalyst for hydrazine oxidation reaction(HzOR)in alkaline electrolytes.A full electrolytic system employing Cu_(3)P/CF as both an anode for HzOR and a cathode for hydrogen evolution reaction drives 100 mA cm^(-2)at a voltage of 0.72 V in 1.0 M KOH aqueous solution with 0.5 M hydrazine.It also demonstrates high long-term stability.
基金supported by the National Natural Science Foundation of China(no.11974229)the Applied and Basic Research Program of Shanxi Province(no.20210302123327)the Innovation Project of Graduate Education in Shanxi Province(no.2023XBY005).
文摘Co-based spinel oxides with unique crystal structures have been identified as a class of promising candidates for alkaline water oxidation catalysis in oxide structural families.Unfortunately,their relatively poor conductivity exerts significant negative impacts on efficient charge transfer,thereby inhibiting the enhancement of their intrinsic activity for electrochemical water splitting.Optimizing the electronic structure of the catalytically active sites of Co-based spinel oxide electrocatalysts is of great significance for improving the electrocatalytic performance.Herein,a facile heterometal doping strategy is reported to synthesize an oxygen-vacancy-rich Ru-doped Co_(3)O_(4) nanosheet array on a cobalt foam substrate(denoted as Ru-Co_(3)O_(4)|VO/CF)as a trifunctional catalyst for significantly boosting the hydrogen evolution reaction(HER),oxygen evolution reaction(OER)and hydrazine oxidation reaction(HzOR)electrocatalytic activities,which involves the electrodeposition process,cation exchange approach,and subsequent thermal oxidation treatment.Benefiting from the 3D hierarchical structural merits and more exposed active sites caused by local Jahn-Teller distortions,the optimized catalyst exhibits excellent catalytic performance towards the HER and OER,affording a current density of 100 mA cm^(-2) at low overpotentials of 48.6 and 270 mV in 1 M KOH,respectively,along with remarkable stability and durability.Interestingly,the integrated Ru-Co_(3)O_(4)|VO/CF water electrolyzer only requires a low cell voltage of 1.47 V to reach 10 mA cm^(-2),outperforming the benchmark couple of the Pt/C(−)||RuO2(+)electrode and most reported counterparts.More impressively,a hydrazine-assisted water electrolysis electrolyzer is subsequently assembled by using Ru-Co_(3)O_(4)|VO/CF electrodes,delivering a current density of 100 mA cm^(-2) with an ultralow operating voltage of 0.70 V,which is 1.1 V lower than that of its hydrazine free counterpart.Density functional theory results reveal that the synergistic effect of Ru doping and oxygen vacancies could effectively modify the spin configuration(eg orbital occupancy),tune the d-band center of Co ions and optimize the Gibbs free energy of hydrogen adsorption and the adsorption energy of OER intermediates,consequently resulting in the enhancement of the intrinsic catalytic activity of Co_(3)O_(4).This work provides important referential value for fabricating highly efficient and stable catalysts towards sustainable energy conversion and storage.
基金funded by the National Natural Science Foundation of China(51702213)support from the Shanghai Chenguang Program(17CG48),the Shanghai Pujiang Program(17PJ1406900)+2 种基金the Shanghai Science and Technology Commission(18060502300)supports from the Australian Research Council under the Future Fellowships scheme(FT160100107)Discovery Programme(DP180102210).
文摘Molybdenum phosphides(MoP)are emerging as an attractive catalyst for water splitting due to their excellent activity and stability.However,most of the MoP synthesized so far are crystalline MoP with relatively fewer exposed active sites and low electrical conductivity.Here,we use a metallo-organic Mo precursor(MoO_(2)(acac)_(2))to create defect-rich crystalline MoP nanoparticles and uniformly anchor them on reduced graphene oxide(denoted as D-MoP/rGO).High-temperature thermal decomposition of the precursor generates gases,which induce a variety of defects in D-MoP/rGO along with a P-rich surface composition.The electrochemically active surface area of D-MoP/rGO is 8 times that of bulk MoP.D-MoP/rGO requires a small overpotential of 122 mV for the hydrogen evolution reaction(HER)to reach a current density of 10 mA cm^(-2).Furthermore,density functional theory(DFT)calculation results reveal that surface P sites are the key active sites,which favor the adsorption of H atoms and also act as an H deliverer to promote the HER.Importantly,D-MoP/rGO is also a highly active catalyst for the hydrazine oxidation reaction(HzOR)and requires a low overpotential of 84 mV to reach a current density of 10 mA cm^(-2).Thus,efficient HER||HzOR hybrid water-splitting can be realized using D-MoP/rGO,which can deliver a current density of 100 mA cm^(-2)at a small cell voltage of 0.74 V and undergo a stable 12 h operation.In summary,a simple method has been demonstrated to generate high-performance metal phosphide electrocatalysts for total water splitting.Furthermore,the material design concept of creating defective crystalline nanoparticles using gas generating metal precursors can serve as a general approach to create various catalytic active defective crystalline materials.
