Promising aqueous zinc metal batteries(AZMBs)continue to face significant challenges regarding zinc anode reversibility due to detrimental reactions including hydrogen evolution and corrosion.Herein,the d-band center ...Promising aqueous zinc metal batteries(AZMBs)continue to face significant challenges regarding zinc anode reversibility due to detrimental reactions including hydrogen evolution and corrosion.Herein,the d-band center is used as an“intuitive descriptor”to compare the hydrogen evolution activity of zinc-based transition bimetallic oxides(ZTBOs)of fourth-period transition metal elements,and the advantages of ZnTi_(3)O_(7)(ZTO)functional protective layer in inhibiting hydrogen evolution and extending the lifespan of the zinc anode are selectively identified.展开更多
Seawater electrolysis holds significant importance for advancing clean energy conversion.NiFe-based catalysts exhibit outstanding performance in the oxygen evolution reaction(OER)under alkaline conditions.However,the ...Seawater electrolysis holds significant importance for advancing clean energy conversion.NiFe-based catalysts exhibit outstanding performance in the oxygen evolution reaction(OER)under alkaline conditions.However,the instability of the Fe active center leads to leakage issues,hindering further development in the field of seawater electrolysis.Here,we adopt an element doping engineering strategy to enhance the OER activity of Ni-Fe oxyhydroxides and greatly stabilize the Fe sites by meticulously optimizing the d-band centers.Among the selected metals(Al,Ce,Co,Cr,Cu,Mn,Sn,Zn and Zr),Mn doping is the most effective as confirmed by both theoretical calculations and experimental verifications.The NiFeMn-OOH/NF formed in situ from the corresponding metal-organic framework requires only 217 mV to achieve a current density of 10 mA·cm^(–2) in alkaline seawater,and exhibits exceptional stability.Theoretical calculations uncover that the Fe sites exhibit better balance of adsorption-desorption kinetics for OER intermediates than Ni sites and Ni-Fe dual-sites,while Mn sites with the polyvalent nature modulate the d-band center closer to Fermi level,facilitate the transfer of electrons across the catalyst surface,thus accelerating the reaction kinetics.This work is of considerable significance for achieving efficient and sustainable seawater electrolysis.展开更多
Green hydrogen is crucial for advancing renewable energy technologies and protecting the environment.This study introduces a controllable method for bimetallic nickel-cobalt phosphide on reduced graphene oxide on nick...Green hydrogen is crucial for advancing renewable energy technologies and protecting the environment.This study introduces a controllable method for bimetallic nickel-cobalt phosphide on reduced graphene oxide on nickel foam(NiCo_(3)P.C/NF).The material demonstrated low overpotentials of 58 and 180 mV at10 mA cm^(-2)for hydrogen evolution reaction(HER)and oxygen evolution reaction(OER)in 1.0 M KOH.It achieved excellent electrochemical water-splitting performance with operating voltages of 1.54 and 2.6 V at 10 and 500 mA cm^(-2),respectively.The overall water-splitting performance of NiCo_(3).C/NF was extremely stable after 75 h of operation at 53 mA cm^(-2),retaining 98%efficiency,better than the sample Pt-C+RuO_(2),and outperforming previous reports.Density functional theory(DFT)results revealed a synergistic NiCo_(3)P.C interaction that yields nearly zero Gibbs free energy change(-0.100 eV)and upshift d-band center,the real active site at the Ni in HER,and the lowest overpotentials 0.26 V at the P active sites for OER.Furthermore,electronic charge distribution shows the maximum charge distribution between the NiCo_(3)P phase and graphene sheet heterojunction,enhancing the electrocatalyst conductivity.This combined approach offers an innovative strategy to design sustainable electrocatalysts for water s plitting.展开更多
The polysulfide shuttle effect critically hinders lithium-sulfur(Li-S)battery development,therefore,the design of heterogeneous interface engineering with“adsorption-catalysis”functions for polysulfide conversion ha...The polysulfide shuttle effect critically hinders lithium-sulfur(Li-S)battery development,therefore,the design of heterogeneous interface engineering with“adsorption-catalysis”functions for polysulfide conversion has garnered considerable attention.However,the exploration of the intricate relationship between key electronic properties and catalytic activity at such interfaces remains a challenge.Additionally,a comprehensive understanding of the thermodynamic growth mechanisms for heterostructure materials is lacking.Herein,a Ni-based homologous structure was precisely constructed via thermodynamic control,with a specific focus on optimizing the interface design.The theoretical results show that the heterostructures with adjustable composition realize the appropriate upward shift to the D-band,improving the affinity towards polysulfide,and further reducing the reaction energy barrier.On this basis,the relationship between interface design and the D-band center,as well as catalytic performance,was established.Specifically,M-Ni_(3)Fe/Ni_(3)ZnC_(0.7)accomplishes the electron enrichment at the interface,supporting the further diffusion of polysulfides,and lowering the Li-S bond energy,performing the bidirectional catalytic transformation of polysulfides.As a result,the Li-S batteries with the cathode of M-Ni_(3)Fe/Ni_(3)ZnC_(0.7)/S deliver rate performances of discharge capacity of 514 mA h g^(−1)at 5.0 C.This understanding of the D-band and interfacial design provides a framework for Li-S catalyst optimization.展开更多
The slow conversion of polyphase in lithium-sulfur(Li-S)batteries not only intensifies the shuttle effect of lithium polysulfides(LiPSs),but also causes the continuous accumulation of inactive sulfur species,resulting...The slow conversion of polyphase in lithium-sulfur(Li-S)batteries not only intensifies the shuttle effect of lithium polysulfides(LiPSs),but also causes the continuous accumulation of inactive sulfur species,resulting in rapid capacity attenuation and sluggish dynamic performance.Herein,the promoting effect of atomic interface stress on sulfur reaction was investigated via CoFe-CoFe_(2)O_(4)heterogeneous nanosheets with a cavity structure.The strain force induced by the in-situ precipitation of Co Fe bimetallic alloy in oxide matrix increased the d-band center,which was conducive to the interaction between catalyst and Li PSs.The sulfur cathode based on this two-dimensional(2D)nanosheet design showed an extremely high capacity of 751 mAh g^(-1)at 4 C.Even with a sulfur loading of 5.55 mg cm^(-2),its area capacity was still as high as 7.15 mAh cm^(-2).Meanwhile,the enhanced stability greatly improved the practical potential of Li-S batteries.展开更多
Constructing heterostructures to regulate the electronic structure is an effective strategy for enhancing the oxygen evolution reaction(OER)electrocatalytic activity.Herein,we prepared heterostructured Co_(4)S_(3)/CoP...Constructing heterostructures to regulate the electronic structure is an effective strategy for enhancing the oxygen evolution reaction(OER)electrocatalytic activity.Herein,we prepared heterostructured Co_(4)S_(3)/CoP3(CoPS/NFF)electrocatalysts through a one-step phosphorization and sulfuration process.The synthesized electrode drives an overpotential of 190,272 and 331 mV at 20,50 and 100 mA cm^(−2) for OER in 1 M KOH alkaline media,respectively.These values outperformed those of monophase Co_(4)S_(3) and CoP3 as well as the majority of transition metal-based catalysts previously reported.Furthermore,the Density Functional Theory(DFT)calculation results show that charge redistribution occurs at CoPS/NFF heterogeneous interfaces,which facilitates charge transfer and improves catalytic activity.The CoPS/NFF with heterostructure optimizes the adsorption strength of oxygen-containing intermediates(*O,*OH and*OOH)by appropriately adjusting the d-band center energy level,thereby reducing the energy barrier of OER.This work provides a new perspective on rational design strategies for efficient transition metal-based electrocatalysts by inducing d-band center regulation through the construction of heterostructures.展开更多
Serpentine structured Co_(3)Si_(2)O_(5)(OH)_(4) is inexpensive,chemically stable,and electrochemically active in oxygen evolution reactions(OER).However,the OER activity of Co_(3)Si_(2)O_(5)(OH)_(4) materials is still...Serpentine structured Co_(3)Si_(2)O_(5)(OH)_(4) is inexpensive,chemically stable,and electrochemically active in oxygen evolution reactions(OER).However,the OER activity of Co_(3)Si_(2)O_(5)(OH)_(4) materials is still unfavorable due to the low active sites.Here,Mn^(2+)-doped Co_(3)Si_(2)O_(5)(OH)_(4) serpentine nanosheets with tuned d-band centers are achieved for efficient oxygen evolution in alkaline and neutral electrolytes.The Co_(x)Mn_(3−x)Si_(2)O_(5)(OH)_(4) serpentine nanosheets are synthesized by a simple hydrothermal method.The optimized Co_(2.4)Mn_(0.6)Si_(2)O_(5)(OH)_(4) serpentine nanosheets showed favorable OER overpotentials as well as stable durability in KOH solution and phosphate buffer solution,which were superior to most of the Co-based and Mn-based OER electrocatalysts.The in situ Raman spectroscopy shows that the materials are kept well in the electrochemical OER environments.Further density functional theory shows that the d-band center of Co_(x)Mn_(3−x)Si_(2)O_(5)(OH)_(4) serpentine nanosheets is shifted more upward in comparison with pristine Co_(3)Si_(2)O_(5)(OH)_(4).The changes in the d-band center increase the adsorption of intermediates,optimize the reaction steps,and lower the energy barriers of the OER.That is the main reason for the OER enhancement Mn^(2+)-doped Co_(3)Si_(2)O_(5)(OH)_(4).This work gives an efficient strategy to design cheap and stable electrocatalytic materials for OER in a broad pH environment.展开更多
The strong hydrogen binding affinity on Ru surfaces and their intrinsic aggregation tendency pose significant challenges to the hydrogen evolution reaction(HER)activity of Ru-based electrocatalysts.The construction of...The strong hydrogen binding affinity on Ru surfaces and their intrinsic aggregation tendency pose significant challenges to the hydrogen evolution reaction(HER)activity of Ru-based electrocatalysts.The construction of active electrocatalysts composed of partially dispersed nanoparticles(NPs)and individual single atomic site with robust thermodynamic stability,has emerged as a viable alternative to benchmark commercial HER electrocatalyst.Herein,a multi-step strategy was designed to synthesize Ru_(NP)@Fe_(SA)-NC electrocatalyst,and a robust interaction between uniformly dispersed Ru NPs and embedded single-atom Fe sites was uncovered,which not only regulates the particle size of Ru NPs but also controls the spin state and electronic configuration of Fe single atom.Moreover,magnetic characterization reveals that the synergetic effect induces a high spin state of the Fe atom with unpaired electrons in the 3d orbitals,which enhances the adsorption of intermediates and accelerates the reaction kinetics.The as obtained electrocatalyst demonstrates a low overpotential of 13 mV at 10 mA cm^(-2)in alkaline condition.Remarkably,theoretical calculation indicates that the outstanding performance of Ru_(NP)@Fe_(SA)-NC stems from the Fe optimized electronic structure of the Ru site,which downshifts the d-band center,reduces the energy barriers for water dissociation and optimizes H^(*)desorption,thereby promoting HER.This study presents an innovative approach to utilize Fe_(SA)-NC to stabilize Ru NPs and reduce the energy barrier,contributing to an ideal HER performance.展开更多
MnO_(2)has emerged as one of the favored cathode materials for aqueous zinc ion batteries(AZIBs)due to its high theoretical capacity and abundant crystalline structures.However,MnO_(2)cathode generally suffers from po...MnO_(2)has emerged as one of the favored cathode materials for aqueous zinc ion batteries(AZIBs)due to its high theoretical capacity and abundant crystalline structures.However,MnO_(2)cathode generally suffers from poor electrical conductivity and rapid capacity degradation due to unavoidable manganese dissolution during cycling,limiting their further utilization.In this study,we modify the d-band center of Mn by introducing non-precious metal Bi atoms into the MnO_(2)system,thereby strengthening the Mn-O bonding to inhibit manganese dissolution.Theoretical calculations reveal that the d-band center of Mn in Bi-MnO_(2)shifts upward,promoting electron transfer from O 2p orbitals to Mn-O bonding orbitals.This enhances the Mn-O bond strength,stabilizing Mn atoms in the crystal lattice and reducing manganese solvation loss.As a result,the conductivity and cyclic stability of Bi-MnO_(2)are significantly improved.The results demonstrate that Bi-MnO_(2)exhibits outstanding electrochemical properties,with a capacity of 392.3 mAh g^(-1)after 100 cycles at 0.2 A g^(-1)and a capacity retention of 83.25%after 5000 cycles at 1.0 A g^(-1).This study presents a new approach to address the manganese dissolution issue,which could further advance the application of d-band center theory in MnO_(2)materials.展开更多
The modulating effects of Cu modification and oxalate or borohydride ligands functionalization on the structure,catalyst d-band center(εd),upper d-band edge(εu),and acetylene partial hydrogenation of expediently syn...The modulating effects of Cu modification and oxalate or borohydride ligands functionalization on the structure,catalyst d-band center(εd),upper d-band edge(εu),and acetylene partial hydrogenation of expediently synthesized Ce alloyed Pt supported catalysts were investigated.Firstly,a 5 wt%Pt alloyed Ce was synthesized via flame spray pyrolysis.The PtCe sample was further supported on zeolite Y,ZY,(PtCe/ZY)and copper modified ZY(PtCe/Cu-ZY).Furthermore,the PtCe was supported on two other oxalate and borohydride ligands functionalized copper modified ZY(PtCe/CuX-ZY and PtCe/CuB-ZY,respectively).The high-angle annular darkfield scanning transmission electron microscopy(HAADF/STEM)data showed a reduction in the PtO average particle size from 2.65 nm in PtCeO_(2) to average 1.73,0.64,and 0.30 nm in PtCe/Cu-ZY,PtCe/CuX-ZY,and PtCe/CuB-ZY,which was corroborated by the electron energy-loss spectroscopy(EELS)results wherein nonhomogeneous mixing of elements was seen with segregated Pt clusters in the non-functionalized samples.Conversely,both PtCe/CuX-ZY and PtCe/CuBZY samples showed near-perfect homogeneity with no distinct Pt signals.The measuredεu values for PtCe,PtCe/Cu-ZY,PtCe/CuX-ZY,and PtCe/CuB-ZY are+1.85,+0.40,-0.15,and-0.19 eV,respectively.The positive values indicated strong metal-adsorbate bonding typical of large Pt sizes while the negative values indicated weak metal-adsorbate bonding due to highly downsized Pt sizes.The ethylene yield(YC2H4)over the PtCe sample showed depletion as the reaction temperature increased,while it reflected maxima at 120℃ with 55.3%YC2H4 over PtCe/ZY.The maxima shifted to 180℃ with enhanced YC2H4 of 71.4%in PtCe/Cu-ZY.On the contrary,both PtCe/CuX-ZY and PtCe/CuB-ZY exhibited a monotonous increase in YC2H4 up to the maximum C_(2)H_(2)conversion with YC2H4 of 81.9%and 92.1%at 180 and 160℃,respectively.These results showed that both the Cu modification and ligands functionalization were highly invaluable to enhance the properties and activities of the semihydrogenation of acetylene(SHA)catalysts.展开更多
Attaining a highly efficient and inexpensive electrocatalyst is significant for the hydrogen evolution reaction(HER)but still challenging nowadays.The transition-metal phosphides(TMPs)catalysts with platinum-like elec...Attaining a highly efficient and inexpensive electrocatalyst is significant for the hydrogen evolution reaction(HER)but still challenging nowadays.The transition-metal phosphides(TMPs)catalysts with platinum-like electronic structures are a potential candidate for the HER,but those are prone to be strongly bound with hydrogen intermediates(H∗),resulting in sluggish HER kinetics.Herein we report a unique hybrid structure of CoP anchored on graphene nanoscrolls@carbon nano tubes(CNTs)scaffold(Ni M@C-CoP)encapsulating various Ni M(M=Zn,Mo,Ni,Co)bimetal nanoalloy via chemical vapor deposi-tion(CVD)growth of CNT on graphene nanoscrolls followed by the impregnation of cobalt precursors and phosphorization for efficiently electrocatalytic hydrogen evolution.CoP nanoparticles mainly scattered at the tip of CNT branches which exhibited the analogical“Three-layer core-shell”structures.Experiments and density functional theory(DFT)calculations consistently disclose that the encapsulated various NiMs can offer different numbers of electrons to weaken the interactions of outmost CoP with H∗and push the downshift of the d-band center to different degrees as well as stabilize the outmost CoP nanopar-ticles to gain catalytic stability via the electron traversing effect.The electrocatalytic HER activity can be maximumly enhanced with low overpotentials of 78 mV(alkaline)and 89 mV(acidic)at a current density of 10 mA/cm^(2) and sustained at least 24 h especially for NiZn@C-CoP catalyst.This novel system is distinct from conventional three-layer heterostructure,providing a specially thought of d-band center control engineering strategy for the design of heterogeneous catalysts and expanding to other electrocat-alysts,energy storage,sensing,and other applications.展开更多
The d-band state of materials is an important descriptor for activity of oxygen evolution reaction(OER).For NiO materials,there is rarely concern about tuning their d-band states to tailor the OER behaviors.Herein,NiO...The d-band state of materials is an important descriptor for activity of oxygen evolution reaction(OER).For NiO materials,there is rarely concern about tuning their d-band states to tailor the OER behaviors.Herein,NiO nanocrystals with doping small amount of La^(3+)were used to regulate d-band states for promoting OER activity.Density of states calculations based on density functional theory revealed that La^(3+)doping produced upper shift of d-band center,which would induce stronger electronic interaction between surface Ni atoms and species of oxygen evolution reaction intermediates.Further density functional theory calculation illustrated that La^(3+)doped NiO possessed reduced Gibbs free energy in adsorbing species of OER intermediate.Predicted by theoretical calculations,trace La^(3+)was introduced into crystal lattice of NiO nanoparticles.The La^(3+)doped NiO nanocrystal showed much promoted OER activity than corresponding pristine NiO product.Further electrochemical analysis revealed that La^(3+)doping into NiO increased the intrinsic activity such as improved active sites and reduced charge transfer resistance.The in-situ Raman spectra suggested that NiO phase in La^(3+)doped NiO could be better maintained than pristine NiO during the OER.This work provides an effective strategy to tune the d-band center of NiO for efficient electrocatalytic OER.展开更多
Photoreduction of CO_(2) to solar fuels has caused great interest,but suffers from low catalytic efficiency and poor selectivity.Herein,we designed a S-scheme heterojunction(Cu-TiO_(2)/WO_(3))with Cu single atom to si...Photoreduction of CO_(2) to solar fuels has caused great interest,but suffers from low catalytic efficiency and poor selectivity.Herein,we designed a S-scheme heterojunction(Cu-TiO_(2)/WO_(3))with Cu single atom to significantly boost the photoreduction of CO_(2).Notably,the developed Cu-TiO_(2)/WO_(3) achieved the solardriven conversion of CO_(2) to CH_(4) with an evolution rate of 98.69μmol g^(−1) h^(−1),and the electron selectivity of CH_(4) reached 88.5%.The yield was much higher than those of pristine WO_(3),TiO_(2)/WO_(3) and Cu-TiO_(2) samples.Experimental and theoretical analysis suggested that the S-scheme heterojunction accelerated charge migration and inhibited the recombination of electron-hole pairs.Importantly,the charge separation effect of the heterojunction meliorated the position of the d-band.The uplifted d-band centers of Cu and Ti on Cu-TiO_(2)/WO_(3) not only improved the electron interaction between Cu single atoms and substrate-TiO_(2),accelerated the adsorption and activation of CO_(2) on the active sites of Cu single atom,but also optimized the Gibbs free energies of CH 4 formation pathway,leading to excellent selectivity toward CH_(4).This work provides new insights into the design of photocatalyst systems with high photocatalytic performance.展开更多
The d-band centers of catalysts have exhibited excellent performance in various reactions.Among them,the enhanced catalytic reaction is considered a crucial way to power dynamics and reduce the“shuttle”effect in pol...The d-band centers of catalysts have exhibited excellent performance in various reactions.Among them,the enhanced catalytic reaction is considered a crucial way to power dynamics and reduce the“shuttle”effect in polysulfide conversions of lithium-sulfur batteries.Here,we report two-dimensional-shaped tungsten borides(WB)nanosheets with d-band centers,where the d orbits of W atoms on the(001)facets show greatly promoting the electrocatalytic sulfur reduction reaction.As-prepared WB-based Li-S cells exhibit excellent electrochemical performance for Li-ion storage.Especially,it delivers superior capacities of 7.7 mAh/cm^(2) under the 8.0 mg/cm^(2) sulfur loading,which is far superior to most other electrode catalysts.This study provides insights into the d-band centers as a promising catalyst of twodimensional boride materials.展开更多
Tuning the coordination atoms of central metal is an effective means to improve the electrocatalytic activity of atomic catalysts.Herein,iridium(Ir) is proposed to be asymmetrically anchored by sp-N and pyridinic N of...Tuning the coordination atoms of central metal is an effective means to improve the electrocatalytic activity of atomic catalysts.Herein,iridium(Ir) is proposed to be asymmetrically anchored by sp-N and pyridinic N of hydrogen-substituted graphdiyne(HsGDY),and coordinated with OH as an Ir atomic catalyst(Ir_(1)-N-HsGDY).The electron structures,especially the d-band center of Ir atom,are optimized by these specific coordination atoms.Thus,the as-synthesized Ir_(1)-N-HsGDY exhibits excellent electrocatalytic performances for oxygen reduction and hydrogen evolution reactions in both acidic and alkaline media.Benefiting from the unique structure of HsGDY,IrN_(2)(OH)_(3) has been developed and demonstrated to act as the active site in these electrochemical reactions.All those indicate the fresh role of the sp-N in graphdiyne in producing a new anchor way and contributing to promote the electrocatalytic activity,showing a new strategy to design novel electrochemical catalysts.展开更多
Since the D-band center theory was proposed,it has been widely used in the fields of surface chemistry by almost all researchers,due to its easy understanding,convenient operation and relative accuracy.However,with th...Since the D-band center theory was proposed,it has been widely used in the fields of surface chemistry by almost all researchers,due to its easy understanding,convenient operation and relative accuracy.However,with the continuous development of material systems and modification strategies,researchers have gradually found that D-band center theory is usually effective for large metal particle systems,but for small metal particle systems or semiconductors,such as single atom systems,the opposite conclusion to the D-band center theory is often obtained.To solve the issue above,here we propose a bonding and anti-bonding orbitals stable electron intensity difference(BASED)theory for surface chemistry.The newly-proposed BASED theory can not only successfully explain the abnormal phenomena of D-band center theory,but also exhibits a higher accuracy for prediction of adsorption energy and bond length of intermediates on active sites.Importantly,a new phenomenon of the spin transition state in the adsorption process is observed based on the BASED theory,where the active center atom usually yields an unstable high spin transition state to enhance its adsorption capability in the adsorption process of intermediates when their distance is about 2.5Å.In short,the BASED theory can be considered as a general principle to understand catalytic mechanism of intermediates on surfaces.展开更多
Aqueous zinc-ion batteries(AZIBs)are promising for energy storage.However,Zn anode instability—caused by dendrite growth,hydrogen evolution reaction(HER),and by-product formation—limits their practical viability.HER...Aqueous zinc-ion batteries(AZIBs)are promising for energy storage.However,Zn anode instability—caused by dendrite growth,hydrogen evolution reaction(HER),and by-product formation—limits their practical viability.HER,in particular,accelerates Zn consumption,disrupts electrode integrity,and induces local alkalization,exacerbating passivation.Conventional strategies emphasize electrolyte formulation and surface passivation,yet few address the underlying electronic origin of HER on Zn.Here we report a catalysis-inspired strategy that electronically modulates Zn reactivity via d-band center engineering to intrinsically suppress HER.By introducing oxalic acid(OA)as a molecular additive,we achieve a significant downward shift in the Zn d-band center(from–6.896 to–7.062 eV),weakening hydrogen adsorption and fundamentally reducing HER activity.In parallel,OA disrupts the Zn^(2+)solvation structure by displacing coordinated SO_(4)^(2-)anions,suppressing interfacial by-product formation.These dual effects yield unprecedented performance:Zn||Zn symmetric cells operate stably for over 3500 h;Zn||Cu cells exhibit 99.41%Coulombic efficiency over 1500 cycles;and Zn||I2 cell retain 92.8%capacity after 10,000 cycles;the 1.3 Ah Zn||I2 pouch cell presents good cyclability.This work pioneers a surface electronic tuning paradigm in battery design,extending catalytic d-band theory to electrochemical interfaces for HER suppression and interfacial stabilization in aqueous metal batteries.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
We experimentally demonstrate the transmission of discrete multi-tone(DMT)millimeter-wave(mm-wave)signals over a 1.2-km distance at the D-band(110–170 GHz)in a cost-effective intensity-modulation and direct-detection...We experimentally demonstrate the transmission of discrete multi-tone(DMT)millimeter-wave(mm-wave)signals over a 1.2-km distance at the D-band(110–170 GHz)in a cost-effective intensity-modulation and direct-detection(IM/DD)communication system.In the experiment,we successfully achieve the transmission of DMT-QPSK and DMT-16QAM mm-wave signals over multiple-input multiple-output(MIMO)links.After the 1.2-km free-space transmission,the bit error rate(BER)of the DMT-16QAM is below the 25%soft decision forward error correction(25%SD-FEC)threshold of 4×10^(-2),with a maximum net bit rate of 24.62 Gbit/s achieved in this system.展开更多
The electrochemical upcycling of polyethylene terephthalate(PET)into high-value products,alongside hydrogen production under ambient conditions,represents a promising approach to sustainable waste management.However,t...The electrochemical upcycling of polyethylene terephthalate(PET)into high-value products,alongside hydrogen production under ambient conditions,represents a promising approach to sustainable waste management.However,the mechanism underlying efficient PET-derived ethylene glycol oxidation reactions(EGOR),driven by the enhanced adsorption of key intermediates,remains unclear.In this work,built-in electric fields(BIEF)were deliberately engineered within the heterojunction Ni(OH)_(2)-Ni_(3)S_(2)/NF catalyst,effectively elevating the d-band center and thereby enhancing the adsorption of EG and hydroxyl(*OH)species.This modification significantly accelerates reaction kinetics compared to Ni3S2/NF.Remarkably,the Ni(OH)_(2)-Ni_(3)S_(2)/NF catalyst achieves an industrial current density of 616.0 mA·cm^(-2) at 1.50 V vs.reversible hydrogen electrode(RHE),exhibiting a Faradaic efficiency(FE)of 89%for formate(FA)at 1.45 V vs.RHE.In situ electrochemical infrared absorption spectroscopy(IRAS)and theoretical calculations reveal that FA was primarily generated through C-C bond cleavage in glycolic acid.This study also elucidates the critical relationship between BIEF and d-band center,offering a viable strategy to enhance intermediate adsorption during the EGOR process.展开更多
基金support from National Natural Science Foundation of China(52272198 and 22109163)。
文摘Promising aqueous zinc metal batteries(AZMBs)continue to face significant challenges regarding zinc anode reversibility due to detrimental reactions including hydrogen evolution and corrosion.Herein,the d-band center is used as an“intuitive descriptor”to compare the hydrogen evolution activity of zinc-based transition bimetallic oxides(ZTBOs)of fourth-period transition metal elements,and the advantages of ZnTi_(3)O_(7)(ZTO)functional protective layer in inhibiting hydrogen evolution and extending the lifespan of the zinc anode are selectively identified.
文摘Seawater electrolysis holds significant importance for advancing clean energy conversion.NiFe-based catalysts exhibit outstanding performance in the oxygen evolution reaction(OER)under alkaline conditions.However,the instability of the Fe active center leads to leakage issues,hindering further development in the field of seawater electrolysis.Here,we adopt an element doping engineering strategy to enhance the OER activity of Ni-Fe oxyhydroxides and greatly stabilize the Fe sites by meticulously optimizing the d-band centers.Among the selected metals(Al,Ce,Co,Cr,Cu,Mn,Sn,Zn and Zr),Mn doping is the most effective as confirmed by both theoretical calculations and experimental verifications.The NiFeMn-OOH/NF formed in situ from the corresponding metal-organic framework requires only 217 mV to achieve a current density of 10 mA·cm^(–2) in alkaline seawater,and exhibits exceptional stability.Theoretical calculations uncover that the Fe sites exhibit better balance of adsorption-desorption kinetics for OER intermediates than Ni sites and Ni-Fe dual-sites,while Mn sites with the polyvalent nature modulate the d-band center closer to Fermi level,facilitate the transfer of electrons across the catalyst surface,thus accelerating the reaction kinetics.This work is of considerable significance for achieving efficient and sustainable seawater electrolysis.
基金supported by the Regional Leading Research Center Program(2019R1A5A8080326)funding from the Basic Science Research Program(2021R1F1A1048758,2022R1I1A1A01053248)+1 种基金the Regional Innovation Strategy(RIS)(2023RIS-008)through the National Research Foundation of Korea(NRF),funded by the Ministry of Educationsupported by the National Supercomputing Center,which provided supercomputing resources and technical support(TS-2024-RE-0039)。
文摘Green hydrogen is crucial for advancing renewable energy technologies and protecting the environment.This study introduces a controllable method for bimetallic nickel-cobalt phosphide on reduced graphene oxide on nickel foam(NiCo_(3)P.C/NF).The material demonstrated low overpotentials of 58 and 180 mV at10 mA cm^(-2)for hydrogen evolution reaction(HER)and oxygen evolution reaction(OER)in 1.0 M KOH.It achieved excellent electrochemical water-splitting performance with operating voltages of 1.54 and 2.6 V at 10 and 500 mA cm^(-2),respectively.The overall water-splitting performance of NiCo_(3).C/NF was extremely stable after 75 h of operation at 53 mA cm^(-2),retaining 98%efficiency,better than the sample Pt-C+RuO_(2),and outperforming previous reports.Density functional theory(DFT)results revealed a synergistic NiCo_(3)P.C interaction that yields nearly zero Gibbs free energy change(-0.100 eV)and upshift d-band center,the real active site at the Ni in HER,and the lowest overpotentials 0.26 V at the P active sites for OER.Furthermore,electronic charge distribution shows the maximum charge distribution between the NiCo_(3)P phase and graphene sheet heterojunction,enhancing the electrocatalyst conductivity.This combined approach offers an innovative strategy to design sustainable electrocatalysts for water s plitting.
基金supported financially by the National Natural Science Foundation of China(52172242,22109135,52371237)the Science&Technology Talents Lifting Project of Hunan Province(2023TJ-Z32)+2 种基金the Hunan Provincial Education Office Foundation of China(20B570,23B0126)the Natural Science Foundation of Hunan Province(2021JJ30659,2022JJ40423)the Postgraduate Scientific Research Innovation Project of Hunan Province(QL20230146).
文摘The polysulfide shuttle effect critically hinders lithium-sulfur(Li-S)battery development,therefore,the design of heterogeneous interface engineering with“adsorption-catalysis”functions for polysulfide conversion has garnered considerable attention.However,the exploration of the intricate relationship between key electronic properties and catalytic activity at such interfaces remains a challenge.Additionally,a comprehensive understanding of the thermodynamic growth mechanisms for heterostructure materials is lacking.Herein,a Ni-based homologous structure was precisely constructed via thermodynamic control,with a specific focus on optimizing the interface design.The theoretical results show that the heterostructures with adjustable composition realize the appropriate upward shift to the D-band,improving the affinity towards polysulfide,and further reducing the reaction energy barrier.On this basis,the relationship between interface design and the D-band center,as well as catalytic performance,was established.Specifically,M-Ni_(3)Fe/Ni_(3)ZnC_(0.7)accomplishes the electron enrichment at the interface,supporting the further diffusion of polysulfides,and lowering the Li-S bond energy,performing the bidirectional catalytic transformation of polysulfides.As a result,the Li-S batteries with the cathode of M-Ni_(3)Fe/Ni_(3)ZnC_(0.7)/S deliver rate performances of discharge capacity of 514 mA h g^(−1)at 5.0 C.This understanding of the D-band and interfacial design provides a framework for Li-S catalyst optimization.
基金the National Natural Science Foundation of China(No.52207227)the Fundamental Research Funds for the Central Universities(No.0213-14380196)+1 种基金the Science and Technology Project of Nanchang(No.2017-SJSYS-008)the Anhui Absorption Spectroscopy Analysis Instrument Co,Ltd.for XAFS measurements and analysis。
文摘The slow conversion of polyphase in lithium-sulfur(Li-S)batteries not only intensifies the shuttle effect of lithium polysulfides(LiPSs),but also causes the continuous accumulation of inactive sulfur species,resulting in rapid capacity attenuation and sluggish dynamic performance.Herein,the promoting effect of atomic interface stress on sulfur reaction was investigated via CoFe-CoFe_(2)O_(4)heterogeneous nanosheets with a cavity structure.The strain force induced by the in-situ precipitation of Co Fe bimetallic alloy in oxide matrix increased the d-band center,which was conducive to the interaction between catalyst and Li PSs.The sulfur cathode based on this two-dimensional(2D)nanosheet design showed an extremely high capacity of 751 mAh g^(-1)at 4 C.Even with a sulfur loading of 5.55 mg cm^(-2),its area capacity was still as high as 7.15 mAh cm^(-2).Meanwhile,the enhanced stability greatly improved the practical potential of Li-S batteries.
基金supported by the Natural Science Foundation Project of Jilin Province(Nos.YDZJ202401471ZYTS,YDZJ202301ZYTS255,YDZJ202102CXJD049,and 20220201125GX)the Project of Jilin Province Development and Reform Commission(No.2023C032-2).
文摘Constructing heterostructures to regulate the electronic structure is an effective strategy for enhancing the oxygen evolution reaction(OER)electrocatalytic activity.Herein,we prepared heterostructured Co_(4)S_(3)/CoP3(CoPS/NFF)electrocatalysts through a one-step phosphorization and sulfuration process.The synthesized electrode drives an overpotential of 190,272 and 331 mV at 20,50 and 100 mA cm^(−2) for OER in 1 M KOH alkaline media,respectively.These values outperformed those of monophase Co_(4)S_(3) and CoP3 as well as the majority of transition metal-based catalysts previously reported.Furthermore,the Density Functional Theory(DFT)calculation results show that charge redistribution occurs at CoPS/NFF heterogeneous interfaces,which facilitates charge transfer and improves catalytic activity.The CoPS/NFF with heterostructure optimizes the adsorption strength of oxygen-containing intermediates(*O,*OH and*OOH)by appropriately adjusting the d-band center energy level,thereby reducing the energy barrier of OER.This work provides a new perspective on rational design strategies for efficient transition metal-based electrocatalysts by inducing d-band center regulation through the construction of heterostructures.
基金supported by the National Natural Science Foundation of China(No.22072183)the Natural Science Foundation of Hunan Province,China(No.2022JJ30690)the High Performance Computing Center of Central South University.
文摘Serpentine structured Co_(3)Si_(2)O_(5)(OH)_(4) is inexpensive,chemically stable,and electrochemically active in oxygen evolution reactions(OER).However,the OER activity of Co_(3)Si_(2)O_(5)(OH)_(4) materials is still unfavorable due to the low active sites.Here,Mn^(2+)-doped Co_(3)Si_(2)O_(5)(OH)_(4) serpentine nanosheets with tuned d-band centers are achieved for efficient oxygen evolution in alkaline and neutral electrolytes.The Co_(x)Mn_(3−x)Si_(2)O_(5)(OH)_(4) serpentine nanosheets are synthesized by a simple hydrothermal method.The optimized Co_(2.4)Mn_(0.6)Si_(2)O_(5)(OH)_(4) serpentine nanosheets showed favorable OER overpotentials as well as stable durability in KOH solution and phosphate buffer solution,which were superior to most of the Co-based and Mn-based OER electrocatalysts.The in situ Raman spectroscopy shows that the materials are kept well in the electrochemical OER environments.Further density functional theory shows that the d-band center of Co_(x)Mn_(3−x)Si_(2)O_(5)(OH)_(4) serpentine nanosheets is shifted more upward in comparison with pristine Co_(3)Si_(2)O_(5)(OH)_(4).The changes in the d-band center increase the adsorption of intermediates,optimize the reaction steps,and lower the energy barriers of the OER.That is the main reason for the OER enhancement Mn^(2+)-doped Co_(3)Si_(2)O_(5)(OH)_(4).This work gives an efficient strategy to design cheap and stable electrocatalytic materials for OER in a broad pH environment.
基金supported by the National Key Research and Development Program of China(No.2021YFC2901100)the National Natural Science Foundation of China(No.22478425 and 52274307)the Science Foundation of China University of Petroleum,Beijing(2462025QZDX001)。
文摘The strong hydrogen binding affinity on Ru surfaces and their intrinsic aggregation tendency pose significant challenges to the hydrogen evolution reaction(HER)activity of Ru-based electrocatalysts.The construction of active electrocatalysts composed of partially dispersed nanoparticles(NPs)and individual single atomic site with robust thermodynamic stability,has emerged as a viable alternative to benchmark commercial HER electrocatalyst.Herein,a multi-step strategy was designed to synthesize Ru_(NP)@Fe_(SA)-NC electrocatalyst,and a robust interaction between uniformly dispersed Ru NPs and embedded single-atom Fe sites was uncovered,which not only regulates the particle size of Ru NPs but also controls the spin state and electronic configuration of Fe single atom.Moreover,magnetic characterization reveals that the synergetic effect induces a high spin state of the Fe atom with unpaired electrons in the 3d orbitals,which enhances the adsorption of intermediates and accelerates the reaction kinetics.The as obtained electrocatalyst demonstrates a low overpotential of 13 mV at 10 mA cm^(-2)in alkaline condition.Remarkably,theoretical calculation indicates that the outstanding performance of Ru_(NP)@Fe_(SA)-NC stems from the Fe optimized electronic structure of the Ru site,which downshifts the d-band center,reduces the energy barriers for water dissociation and optimizes H^(*)desorption,thereby promoting HER.This study presents an innovative approach to utilize Fe_(SA)-NC to stabilize Ru NPs and reduce the energy barrier,contributing to an ideal HER performance.
基金supported by the Beijing Natural Science Foundation(No.2202050).
文摘MnO_(2)has emerged as one of the favored cathode materials for aqueous zinc ion batteries(AZIBs)due to its high theoretical capacity and abundant crystalline structures.However,MnO_(2)cathode generally suffers from poor electrical conductivity and rapid capacity degradation due to unavoidable manganese dissolution during cycling,limiting their further utilization.In this study,we modify the d-band center of Mn by introducing non-precious metal Bi atoms into the MnO_(2)system,thereby strengthening the Mn-O bonding to inhibit manganese dissolution.Theoretical calculations reveal that the d-band center of Mn in Bi-MnO_(2)shifts upward,promoting electron transfer from O 2p orbitals to Mn-O bonding orbitals.This enhances the Mn-O bond strength,stabilizing Mn atoms in the crystal lattice and reducing manganese solvation loss.As a result,the conductivity and cyclic stability of Bi-MnO_(2)are significantly improved.The results demonstrate that Bi-MnO_(2)exhibits outstanding electrochemical properties,with a capacity of 392.3 mAh g^(-1)after 100 cycles at 0.2 A g^(-1)and a capacity retention of 83.25%after 5000 cycles at 1.0 A g^(-1).This study presents a new approach to address the manganese dissolution issue,which could further advance the application of d-band center theory in MnO_(2)materials.
文摘The modulating effects of Cu modification and oxalate or borohydride ligands functionalization on the structure,catalyst d-band center(εd),upper d-band edge(εu),and acetylene partial hydrogenation of expediently synthesized Ce alloyed Pt supported catalysts were investigated.Firstly,a 5 wt%Pt alloyed Ce was synthesized via flame spray pyrolysis.The PtCe sample was further supported on zeolite Y,ZY,(PtCe/ZY)and copper modified ZY(PtCe/Cu-ZY).Furthermore,the PtCe was supported on two other oxalate and borohydride ligands functionalized copper modified ZY(PtCe/CuX-ZY and PtCe/CuB-ZY,respectively).The high-angle annular darkfield scanning transmission electron microscopy(HAADF/STEM)data showed a reduction in the PtO average particle size from 2.65 nm in PtCeO_(2) to average 1.73,0.64,and 0.30 nm in PtCe/Cu-ZY,PtCe/CuX-ZY,and PtCe/CuB-ZY,which was corroborated by the electron energy-loss spectroscopy(EELS)results wherein nonhomogeneous mixing of elements was seen with segregated Pt clusters in the non-functionalized samples.Conversely,both PtCe/CuX-ZY and PtCe/CuBZY samples showed near-perfect homogeneity with no distinct Pt signals.The measuredεu values for PtCe,PtCe/Cu-ZY,PtCe/CuX-ZY,and PtCe/CuB-ZY are+1.85,+0.40,-0.15,and-0.19 eV,respectively.The positive values indicated strong metal-adsorbate bonding typical of large Pt sizes while the negative values indicated weak metal-adsorbate bonding due to highly downsized Pt sizes.The ethylene yield(YC2H4)over the PtCe sample showed depletion as the reaction temperature increased,while it reflected maxima at 120℃ with 55.3%YC2H4 over PtCe/ZY.The maxima shifted to 180℃ with enhanced YC2H4 of 71.4%in PtCe/Cu-ZY.On the contrary,both PtCe/CuX-ZY and PtCe/CuB-ZY exhibited a monotonous increase in YC2H4 up to the maximum C_(2)H_(2)conversion with YC2H4 of 81.9%and 92.1%at 180 and 160℃,respectively.These results showed that both the Cu modification and ligands functionalization were highly invaluable to enhance the properties and activities of the semihydrogenation of acetylene(SHA)catalysts.
基金This work was supported by the Science and Technology Pro-gram of Shaanxi Province(No.2019GY-200).Shengwu Guo and Wei Wang contributed to the material TEM and SEM characterizations in this work.
文摘Attaining a highly efficient and inexpensive electrocatalyst is significant for the hydrogen evolution reaction(HER)but still challenging nowadays.The transition-metal phosphides(TMPs)catalysts with platinum-like electronic structures are a potential candidate for the HER,but those are prone to be strongly bound with hydrogen intermediates(H∗),resulting in sluggish HER kinetics.Herein we report a unique hybrid structure of CoP anchored on graphene nanoscrolls@carbon nano tubes(CNTs)scaffold(Ni M@C-CoP)encapsulating various Ni M(M=Zn,Mo,Ni,Co)bimetal nanoalloy via chemical vapor deposi-tion(CVD)growth of CNT on graphene nanoscrolls followed by the impregnation of cobalt precursors and phosphorization for efficiently electrocatalytic hydrogen evolution.CoP nanoparticles mainly scattered at the tip of CNT branches which exhibited the analogical“Three-layer core-shell”structures.Experiments and density functional theory(DFT)calculations consistently disclose that the encapsulated various NiMs can offer different numbers of electrons to weaken the interactions of outmost CoP with H∗and push the downshift of the d-band center to different degrees as well as stabilize the outmost CoP nanopar-ticles to gain catalytic stability via the electron traversing effect.The electrocatalytic HER activity can be maximumly enhanced with low overpotentials of 78 mV(alkaline)and 89 mV(acidic)at a current density of 10 mA/cm^(2) and sustained at least 24 h especially for NiZn@C-CoP catalyst.This novel system is distinct from conventional three-layer heterostructure,providing a specially thought of d-band center control engineering strategy for the design of heterogeneous catalysts and expanding to other electrocat-alysts,energy storage,sensing,and other applications.
基金financial support from the National Natural Science Foundation of China(No.22072183)the Natural Science Foundation of Hunan Province,China(No.2022JJ30690)。
文摘The d-band state of materials is an important descriptor for activity of oxygen evolution reaction(OER).For NiO materials,there is rarely concern about tuning their d-band states to tailor the OER behaviors.Herein,NiO nanocrystals with doping small amount of La^(3+)were used to regulate d-band states for promoting OER activity.Density of states calculations based on density functional theory revealed that La^(3+)doping produced upper shift of d-band center,which would induce stronger electronic interaction between surface Ni atoms and species of oxygen evolution reaction intermediates.Further density functional theory calculation illustrated that La^(3+)doped NiO possessed reduced Gibbs free energy in adsorbing species of OER intermediate.Predicted by theoretical calculations,trace La^(3+)was introduced into crystal lattice of NiO nanoparticles.The La^(3+)doped NiO nanocrystal showed much promoted OER activity than corresponding pristine NiO product.Further electrochemical analysis revealed that La^(3+)doping into NiO increased the intrinsic activity such as improved active sites and reduced charge transfer resistance.The in-situ Raman spectra suggested that NiO phase in La^(3+)doped NiO could be better maintained than pristine NiO during the OER.This work provides an effective strategy to tune the d-band center of NiO for efficient electrocatalytic OER.
基金supported by the grants from the National Natural Science Foundation of China(Nos.21872102 and 22172080)the Tianjin“Project+Team”innovation team,2020.
文摘Photoreduction of CO_(2) to solar fuels has caused great interest,but suffers from low catalytic efficiency and poor selectivity.Herein,we designed a S-scheme heterojunction(Cu-TiO_(2)/WO_(3))with Cu single atom to significantly boost the photoreduction of CO_(2).Notably,the developed Cu-TiO_(2)/WO_(3) achieved the solardriven conversion of CO_(2) to CH_(4) with an evolution rate of 98.69μmol g^(−1) h^(−1),and the electron selectivity of CH_(4) reached 88.5%.The yield was much higher than those of pristine WO_(3),TiO_(2)/WO_(3) and Cu-TiO_(2) samples.Experimental and theoretical analysis suggested that the S-scheme heterojunction accelerated charge migration and inhibited the recombination of electron-hole pairs.Importantly,the charge separation effect of the heterojunction meliorated the position of the d-band.The uplifted d-band centers of Cu and Ti on Cu-TiO_(2)/WO_(3) not only improved the electron interaction between Cu single atoms and substrate-TiO_(2),accelerated the adsorption and activation of CO_(2) on the active sites of Cu single atom,but also optimized the Gibbs free energies of CH 4 formation pathway,leading to excellent selectivity toward CH_(4).This work provides new insights into the design of photocatalyst systems with high photocatalytic performance.
基金supported by the National Natural Science Foundation of China(Nos.61904080,22205101)the Natural Science Foundation of Jiangsu Province(No.BK20190670)+5 种基金the Natural Science Foundation of Colleges and Universities in Jiangsu Province(No.19KJB530008)the Macao Young Scholars Program(No.AM2020005)the High-Performance Computing Cluster(HPCC)of Information and Communication Technology Office(ICTO)at University of Macao,Science and Technology Development Fund,Macao SAR(Nos.0191/2017/A3,0041/2019/A1,0046/2019/AFJ,0021/2019/AIR)University of Macao(Nos.MYRG2017-00216-FST and MYRG2018-00192-IAPME),FDCT Funding Scheme for Postdoctoral Researchers(No.0026/APD/2021)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)the UEA funding,and Guangdong Basic and Applied Basic Research Foundation(No.2022A1515110994).
文摘The d-band centers of catalysts have exhibited excellent performance in various reactions.Among them,the enhanced catalytic reaction is considered a crucial way to power dynamics and reduce the“shuttle”effect in polysulfide conversions of lithium-sulfur batteries.Here,we report two-dimensional-shaped tungsten borides(WB)nanosheets with d-band centers,where the d orbits of W atoms on the(001)facets show greatly promoting the electrocatalytic sulfur reduction reaction.As-prepared WB-based Li-S cells exhibit excellent electrochemical performance for Li-ion storage.Especially,it delivers superior capacities of 7.7 mAh/cm^(2) under the 8.0 mg/cm^(2) sulfur loading,which is far superior to most other electrode catalysts.This study provides insights into the d-band centers as a promising catalyst of twodimensional boride materials.
基金supported by the National Natural Science Foundation of China(22172090,21790051)the National Key Research and Development Project of China(2022YFA1204500,2022YFA1204501)+2 种基金the Natural Science Foundation of Shan-dong Province(ZR2021MB015)the Open Funds of the State Key Laboratory of Electroanalytical Chemistry(SKLEAC202202)the Young Scholars Program of Shandong University。
文摘Tuning the coordination atoms of central metal is an effective means to improve the electrocatalytic activity of atomic catalysts.Herein,iridium(Ir) is proposed to be asymmetrically anchored by sp-N and pyridinic N of hydrogen-substituted graphdiyne(HsGDY),and coordinated with OH as an Ir atomic catalyst(Ir_(1)-N-HsGDY).The electron structures,especially the d-band center of Ir atom,are optimized by these specific coordination atoms.Thus,the as-synthesized Ir_(1)-N-HsGDY exhibits excellent electrocatalytic performances for oxygen reduction and hydrogen evolution reactions in both acidic and alkaline media.Benefiting from the unique structure of HsGDY,IrN_(2)(OH)_(3) has been developed and demonstrated to act as the active site in these electrochemical reactions.All those indicate the fresh role of the sp-N in graphdiyne in producing a new anchor way and contributing to promote the electrocatalytic activity,showing a new strategy to design novel electrochemical catalysts.
文摘Since the D-band center theory was proposed,it has been widely used in the fields of surface chemistry by almost all researchers,due to its easy understanding,convenient operation and relative accuracy.However,with the continuous development of material systems and modification strategies,researchers have gradually found that D-band center theory is usually effective for large metal particle systems,but for small metal particle systems or semiconductors,such as single atom systems,the opposite conclusion to the D-band center theory is often obtained.To solve the issue above,here we propose a bonding and anti-bonding orbitals stable electron intensity difference(BASED)theory for surface chemistry.The newly-proposed BASED theory can not only successfully explain the abnormal phenomena of D-band center theory,but also exhibits a higher accuracy for prediction of adsorption energy and bond length of intermediates on active sites.Importantly,a new phenomenon of the spin transition state in the adsorption process is observed based on the BASED theory,where the active center atom usually yields an unstable high spin transition state to enhance its adsorption capability in the adsorption process of intermediates when their distance is about 2.5Å.In short,the BASED theory can be considered as a general principle to understand catalytic mechanism of intermediates on surfaces.
基金supported by the National Natural Science Foundation of China(52204324 and 22409119)the National Key Research and Development Program of China(2024YFE0116300)+2 种基金the Key Research and Development Program of Hunan(2023SK2053)the China Postdoctoral Science Foundation(2024M751651)Shenzhen Science and Technology Innovation Commission(20231610276)for funding support.
文摘Aqueous zinc-ion batteries(AZIBs)are promising for energy storage.However,Zn anode instability—caused by dendrite growth,hydrogen evolution reaction(HER),and by-product formation—limits their practical viability.HER,in particular,accelerates Zn consumption,disrupts electrode integrity,and induces local alkalization,exacerbating passivation.Conventional strategies emphasize electrolyte formulation and surface passivation,yet few address the underlying electronic origin of HER on Zn.Here we report a catalysis-inspired strategy that electronically modulates Zn reactivity via d-band center engineering to intrinsically suppress HER.By introducing oxalic acid(OA)as a molecular additive,we achieve a significant downward shift in the Zn d-band center(from–6.896 to–7.062 eV),weakening hydrogen adsorption and fundamentally reducing HER activity.In parallel,OA disrupts the Zn^(2+)solvation structure by displacing coordinated SO_(4)^(2-)anions,suppressing interfacial by-product formation.These dual effects yield unprecedented performance:Zn||Zn symmetric cells operate stably for over 3500 h;Zn||Cu cells exhibit 99.41%Coulombic efficiency over 1500 cycles;and Zn||I2 cell retain 92.8%capacity after 10,000 cycles;the 1.3 Ah Zn||I2 pouch cell presents good cyclability.This work pioneers a surface electronic tuning paradigm in battery design,extending catalytic d-band theory to electrochemical interfaces for HER suppression and interfacial stabilization in aqueous metal batteries.
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 the National Key R&D Program of China(No.2023YFB2905600)the National Natural Science Foundation of China(Nos.61935005,62127802,62331004,62305067)the Key Project of Jiangsu Province of China(No.BE2023001-4)。
文摘We experimentally demonstrate the transmission of discrete multi-tone(DMT)millimeter-wave(mm-wave)signals over a 1.2-km distance at the D-band(110–170 GHz)in a cost-effective intensity-modulation and direct-detection(IM/DD)communication system.In the experiment,we successfully achieve the transmission of DMT-QPSK and DMT-16QAM mm-wave signals over multiple-input multiple-output(MIMO)links.After the 1.2-km free-space transmission,the bit error rate(BER)of the DMT-16QAM is below the 25%soft decision forward error correction(25%SD-FEC)threshold of 4×10^(-2),with a maximum net bit rate of 24.62 Gbit/s achieved in this system.
基金financially supported by the National Natural Science Foundation of China(Nos.22279124 and 52261145700)the Natural Science Foundation of Shandong Province(No.ZR2020ZD10)the Fundamental Research Funds for the Central Universities(No.202262010).
文摘The electrochemical upcycling of polyethylene terephthalate(PET)into high-value products,alongside hydrogen production under ambient conditions,represents a promising approach to sustainable waste management.However,the mechanism underlying efficient PET-derived ethylene glycol oxidation reactions(EGOR),driven by the enhanced adsorption of key intermediates,remains unclear.In this work,built-in electric fields(BIEF)were deliberately engineered within the heterojunction Ni(OH)_(2)-Ni_(3)S_(2)/NF catalyst,effectively elevating the d-band center and thereby enhancing the adsorption of EG and hydroxyl(*OH)species.This modification significantly accelerates reaction kinetics compared to Ni3S2/NF.Remarkably,the Ni(OH)_(2)-Ni_(3)S_(2)/NF catalyst achieves an industrial current density of 616.0 mA·cm^(-2) at 1.50 V vs.reversible hydrogen electrode(RHE),exhibiting a Faradaic efficiency(FE)of 89%for formate(FA)at 1.45 V vs.RHE.In situ electrochemical infrared absorption spectroscopy(IRAS)and theoretical calculations reveal that FA was primarily generated through C-C bond cleavage in glycolic acid.This study also elucidates the critical relationship between BIEF and d-band center,offering a viable strategy to enhance intermediate adsorption during the EGOR process.
