Electrocatalytic CO_(2)reduction(ECR)to produce value-added fuels and chemicals using renewable electricity is an emerging strategy to mitigate global warming and decrease reliance on fossil fuels.Among various ECR pr...Electrocatalytic CO_(2)reduction(ECR)to produce value-added fuels and chemicals using renewable electricity is an emerging strategy to mitigate global warming and decrease reliance on fossil fuels.Among various ECR products,liquid oxygenates(Oxys)are especially attractive due to their high energy density,high safety and transportability that could be adapted to the existing infrastructure and transportation system.However,efficiently generating these highly reduced oxygen-containing products by ECR remains challenging due to the complexity of coupled proton and electron transfer processes.In recent years,in-depth studies of reaction mechanisms have advanced the design of catalysts and the regulation of reaction systems for ECR to produce Oxys,Here,by focusing on the production of typical Oxys,such as methanol,acetic acid,ethanol,acetone,n-propanol,and isopropanol,we outline various reaction paths and key intermediates for the electrochemical conversion of CO_(2)into these target products.We also summarize the current research status and recent advances in catalysts based on their elemental composition,and consider recent studies on the change of catalyst geometry and electronic structure,as well as the optimization of reaction systems to increase ECR performance.Finally,we analyze the challenges in the field of ECR to Oxys and provide an outlook on future directions for high-efficiency catalyst prediction and design,as well as the development of advanced reaction systems.展开更多
The adsorption of CO on different lattice oxygen sites in Cu doped CeO_(2)(111)was studied by DFT method,and the geometrical structure and electronic properties of adsorption systems were analyzed.The results showed t...The adsorption of CO on different lattice oxygen sites in Cu doped CeO_(2)(111)was studied by DFT method,and the geometrical structure and electronic properties of adsorption systems were analyzed.The results showed that CO interacted with lattice oxygen on the first layer formed CO_(2).However,when adsorbed on the second layer lattice oxygen,carbonate species were formed with the participation of first layer lattice oxygens,i.e.,CO co-adsorbed on first and second layer lattice oxygens.For the second layer adsorption,the absolute CO adsorption energy was big on the Oss nearby Cu.This kind of carbonates was thermodynamically stable,and it was attributed to the facilitation of Cu on CO adsorption,manifested by an electron migration behavior from the C 2p orbitals to the Cu 3d orbitals.However,the absolute CO adsorption energy on the Oss away from Cu was small.Compared to the formation of carbonates,the formation CO_(2)had very small absolute adsorption energy,suggesting the formed carbonates on second layer was stable.Further,when CO adsorbed on the systems with a carbonate,the absolute CO adsorption energy was significantly smaller than that of the non-carbonated system,indicating that the formation of carbonates inhibited CO oxidation on Cu/CeO_(2)(111).Therefore,the formation of carbonates was unfavorable for CO oxidation reaction on Cu/CeO_(2)(111).The results of this study provide theoretical support for the negative effect of CO_(2)on ceria-based catalysts.展开更多
On the surfaces of celestial bodies with no or thin atmospheres,such as the Moon and Mars,the solar wind irradiation process leads to the formation of hydrogen and helium enriched regions in the extraterrestrial soil ...On the surfaces of celestial bodies with no or thin atmospheres,such as the Moon and Mars,the solar wind irradiation process leads to the formation of hydrogen and helium enriched regions in the extraterrestrial soil particles.However,soil particles on the Earth with the similar composition lack such structures and properties.This discrepancy raises a key question whether there is a direct relationship between solar wind irradiation and the alterations in the structure and chemical performance of extraterrestrial materials.To address this question,this work investigates the effects of proton irradiation,simulating solar wind radiation,on the structure and photothermal catalytic properties of the classic catalyst In_(2)O_(3).It reveals that proton irradiation induces structural features in In_(2)O_(3) analogous to those characteristics of solar wind weathering observed in extraterrestrial materials.Furthermore,after proton beam irradiation with an energy of 30 keV and a dose of 3×10^(17) protons·cm^(-2),the methanol production yield of the In_(2)O_(3) catalyst increased to 2.6 times of its preirradiation level,and the methanol selectivity improved to 2.1 times of the original value.This work provides both theoretical and experimental support for the development of high-efficiency,radiation-resistant photothermal catalysts.展开更多
Amorphous Ga_(2)O_(3)(a-Ga_(2)O_(3))thin films were prepared on flexible polyimide,rigid quartz glass,and Si substrates via radio frequency magnetron sputtering at room temperature.The effect of oxygen/Ar flow rate ra...Amorphous Ga_(2)O_(3)(a-Ga_(2)O_(3))thin films were prepared on flexible polyimide,rigid quartz glass,and Si substrates via radio frequency magnetron sputtering at room temperature.The effect of oxygen/Ar flow rate ratio on the structure,optical property,surface morphology,and chemical bonding properties of the a-Ga_(2)O_(3) films was investigated.Results show that the average optical transmittance of the a-Ga_(2)O_(3) films is over 80%within the wavelength range of 300-2000 nm.The extracted optical band gap of the a-Ga_(2)O_(3) films is increased from 4.97 eV to 5.13 eV with the increase in O_(2)/Ar flow rate ratio from 0 to 0.25,due to the decrease in concentration of oxygen vacancy defects in the film.Furthermore,the optical refractive index and surface roughness of the a-Ga_(2)O_(3) films are optimized when the O_(2)/Ar flow rate ratio reaches 0.25.X-ray photoelectron spectroscopy analysis also shows that the proportion of oxygen vacancies(VO)and Ga-O chemical bonds in the O 1s peak is gradually decreased with the increase in O_(2)/Ar flow rate ratio from 0 to 0.25,proving that increasing the O_(2)/Ar flow rate ratio during film growth can reduce the concentration of oxygen vacancy defects in a-Ga_(2)O_(3) films.In this case,a-Ga_(2)O_(3) with optimal properties can be obtained.This work provides a research basis for high-performance flexible and rigid deep ultraviolet solar-blind detection devices based on a-Ga_(2)O_(3) films.展开更多
The oxygen evolution reaction(OER)serves as a fundamental half–reaction in the electrolysis of water for hydrogen production,which is restricted by the sluggish OER reaction kinetics and unable to be practically appl...The oxygen evolution reaction(OER)serves as a fundamental half–reaction in the electrolysis of water for hydrogen production,which is restricted by the sluggish OER reaction kinetics and unable to be practically applied.The traditional lattice oxygen oxidation mechanism(LOM)offers an advantageous route by circumventing the formation of M-OOH^(*)in the adsorption evolution mechanism(AEM),thus enhancing the reaction kinetics of the OER but resulting in possible structural destabilization due to the decreased M–O bond order.Fortunately,the asymmetry of tetrahedral and octahedral sites in transition metal spinel oxides permits the existence of non-bonding oxygen,which could be activated by rational band structure design for direct O-O coupling,where the M–O bond maintains its initial bond order.Here,non-bonding oxygen was introduced into NiFe_(2)O_(4)via annealing in an oxygen-deficient atmosphere.Then,in-situ grown sulfate species on octahedral nickel sites significantly improved the reactivity of the non-bonding oxygen electrons,thereby facilitating the transformation of the redox center from metal to oxygen.LOM based on non-bonding oxygen(LOMNB)was successfully activated within NiFe_(2)O_(4),exhibiting a low overpotential of 206 mV to achieve a current density of 10 mA cm^(-2)and excellent durability of stable operation for over 150 h.Additionally,catalysts featuring varying band structures were synthesized for comparative analysis,and it was found that the reversible redox processes of non-bonding oxygen and the accumulation of non-bonding oxygen species containing 2p holes are critical prerequisites for triggering and sustaining the LOMNB pathway in transition metal spinel oxides.These findings may provide valuable insights for the future development of spinel-oxide-based LOM catalysts.展开更多
Four-electron oxygen evolving reaction is limited by proton adsorption and desorption,making its reaction kinetics sluggish,which poses a major challenge for catalyst design.Here,we present an unsaturated coordination...Four-electron oxygen evolving reaction is limited by proton adsorption and desorption,making its reaction kinetics sluggish,which poses a major challenge for catalyst design.Here,we present an unsaturated coordination interface by constructing a fast electron transfer channel between Cu_(2)V_(2)O_(7)(CVO)and BiVO4(BVO).X-ray absorption spectroscopy(XAS)and theoretical calculations results confirm that CVO and BVO between interfaces are bonded by the way of unsaturated coordination oxygen(Ouc).The Ouc optimizes the O-O coupled energy barrier at the V active site and promotes the disconnection of O-H bond,which increases the photocurrent intensity of CVO by 6 times.In addition,due to the high electronegativity of the Ouc,the bonding energies of Bi-O and Cu-O at the interface are enhanced,resulting in the long-term stability of the photoanode during the water splitting.Finally,by integrating the working electrode with a polysilicon solar cell,we assembled a device that demonstrated exceptional catalytic performance,achieving a hydrogen production rate of 100.6μmol·cm^(-2),and maintaining a hydrogen-to-oxygen volume ratio of 2:1 after continuous operation for 4 h.This discovery aids in a deeper understanding of photoanode design and offers further insights for industrial applications.展开更多
Single carbon products(C1 compounds) are simple but important chemicals in the road towards energy transition.Catalytic conversion of CO_(2) with H_(2)(desirably renewable) can be performed over reducible oxides suppo...Single carbon products(C1 compounds) are simple but important chemicals in the road towards energy transition.Catalytic conversion of CO_(2) with H_(2)(desirably renewable) can be performed over reducible oxides supporting transition metals to obtain products such as CH_(4),CO and MeOH.Oxygen vacancies(O-vacancies),which are inherent defects of reducible metal oxides,play an enormous role in driving the catalytic performance(activity,selectivity,stability) for the desired reactions.Yet,the assessment of O-defects at realistic conditions is often complex.Only few techniques can provide direct evidence for their existence and influence in CO_(2) activation.Among them,electron paramagnetic spectroscopy(EPR),Raman spectroscopy,scanning probe microscopies(SPM) and environmental transmission electron microscopy(ETEM) are nowadays the most informative.In most cases,however,the measurements require reaction conditions far away from CO_(2) valorization applications.Although great efforts have been fruitful in explaining and demonstrating the huge importance of O-vacancies in CO_(2) catalysis,still ambiguous or erroneous interpretations about structure-function correlations involving O-vacancies are found in literature,especially,when information is not properly gathered,e.g.,by O 1s ex-situ X-ray photon spectroscopy(XPS).Moreover,despite the recognized importance of O-vacancies for CO_(2) valorization,critical literature compilations about their effects in thermal processes are scarce.Herein,we attempt to contribute in closing this gap by integrally encompassing representative investigations on the thermo-catalytic production of CH_(4),CO and MeOH.Particularly,we emphasize on the proper selection of assessment tools(direct/indirect) to unambiguously establish structure-function relationships to design optimized O-defective catalysts for the targeted compounds.展开更多
Despite its high capacity behavior as the anode for lithium-ion batteries (LIBs), SnO_(2) suffers the poorelectronic conductivity and high volume expansion, which lead to poor cycling stability and rate capability. In...Despite its high capacity behavior as the anode for lithium-ion batteries (LIBs), SnO_(2) suffers the poorelectronic conductivity and high volume expansion, which lead to poor cycling stability and rate capability. In this study, we employ defect engineering to design SnO_(2−x)(x = 0, 0.12, 0.2, and 0.3) nanoparticleswith varied oxygen vacancies. Notably, the SnO1.80 electrode with 20 % oxygen vacancies exhibits excellent electrochemical performance. Advanced physical characterizations combined with density functionaltheory (DFT) simulations demonstrate that the improved electrochemical performance can be attributedto the formation of a stable, uniform, and LiF-rich solid-electrolyte interface (SEI) layer through the optimization of oxygen vacancies. This study shows novel insights into the application of defect engineeringwithin oxides for the rational design of the uniform surface layer toward high-energy-density LIBs.展开更多
A hydrogen spillover-bridged water dissociation/hydrogen formation could concurrently promote Volmer/Tafel process and improve the efficiency of hydrogen evolution reaction(HER)under alkaline conditions.However,it is ...A hydrogen spillover-bridged water dissociation/hydrogen formation could concurrently promote Volmer/Tafel process and improve the efficiency of hydrogen evolution reaction(HER)under alkaline conditions.However,it is still challenging to promote occurrence of hydrogen spillover for the large interfacial transport barriers of H_(2)O and hydrogen on active sites.Herein,the strategy of energy barrier gradient to induce hydrogen spillover was proposed by constructing Ru nanoclusters coupled with single atom onto oxygen vacancy cerium dioxide(Ru/CeO_(2)-Ov-2).Density functional theory(DFT)calculations uncover that the adsorption/desorption of H2O occurs at the Ru clusters sites and then the dissociated H*spontaneously overflows from Ru clusters with high binding energy into the adjacent Ru single atom sites with low binding energy,which facilitate the hydrogen formation.Consequently,the synthesized Ru/CeO_(2)-Ov-2 exhibits a small overpotential of 41 mV at 10 mA cm^(-2)and good stability at 500 mA cm^(-2)for 100 h in alkaline seawater,which could be ascribed to the rapid hydrogen spillover and strong coupling interaction between Ru and CeO_(2)-O_(v).This work provides a novel insight that synthesizing cooperative sites with energy barrier gradient helps to promote hydrogen spillover and accelerate the Volmer/Tafel process of HER.展开更多
Although defect engineering has been widely used to boost catalytic CO_(2) photoreduction,the piezoelectric polarized properties induced by structure changes through introducing defects are always ignored.Here we repo...Although defect engineering has been widely used to boost catalytic CO_(2) photoreduction,the piezoelectric polarized properties induced by structure changes through introducing defects are always ignored.Here we report a new kind of bismuth oxybromide(BiOBr,BOB)with piezoelectric property regulated by oxygen vacancies(OVs).Compared with pure BOB,BOB with OVs(BOB-OV)could enhance photocatalytic CO_(2) reduction efficiency under the ultrasonic force,achieving durable CO_(2) reduction process to superior production rates of CO(54.4μmol g^(-1) h^(-1))with a high selectivity(92%).Moderate OVs concentration changed the degree of Bi-Br stretching in the BOB-OV to produce strong dipole moments,which endowed BOB-OV with strong spontaneous piezoelectric polarization ability under external force.Ultrasonic piezoelectric effects were innovatively integrated into the photocatalytic reaction,which not only provided an alternating force field to modulate the spontaneous polarization of BOB-OV,thereby maintaining efficient photogenerated charge separation,but also lowered the reaction energy barrier of CO_(2) by high stress,ultimately improving CO product selectivity.This study is the first to leverage OVs-induced piezoelectric polarization effects to enhance the performance and product selectivity of photocatalytic CO_(2) reduction,providing new directions and insights for defect engineering to contribute to photocatalysis.展开更多
Artificial carbon fixation is a promising pathway for achieving the carbon cycle and environment remediation.However,the sluggish kinetics of oxygen evolution reaction(OER)and poor selectivity of CO_(2) reduction seri...Artificial carbon fixation is a promising pathway for achieving the carbon cycle and environment remediation.However,the sluggish kinetics of oxygen evolution reaction(OER)and poor selectivity of CO_(2) reduction seriously limited the overall conversion efficiencies of solar energy to chemical fuels.Herein,we demonstrated a facile and feasible strategy to rationally regulate the coordination environment and electronic structure of surface-active sites on both photoanode and cathode.More specifically,the defect engineering has been employed to reduce the coordination number of ultrathin FeNi catalysts decorated on BiVO4 photoanodes,resulting in one of the highest OER activities of 6.51 mA cm^(−2)(1.23 VRHE,AM 1.5G).Additionally,single-atom cobalt(II)phthalocyanine anchoring on the N-rich carbon substrates to increase Co–N coordination number remarkably promotes CO_(2) adsorption and activation for high selective CO production.Their integration achieved a record activity of 109.4μmol cm^(−2) h−1 for CO production with a faradaic efficiency of>90%,and an outstanding solar conversion efficiency of 5.41%has been achieved by further integrating a photovoltaic utilizing the sunlight(>500 nm).展开更多
Advanced oxygen carrier plays a pivotal role in various chemical looping processes,such as CO_(2)splitting.However,oxygen carriers have been restricted by deactivation and inferior oxygen transferability at low temper...Advanced oxygen carrier plays a pivotal role in various chemical looping processes,such as CO_(2)splitting.However,oxygen carriers have been restricted by deactivation and inferior oxygen transferability at low temperatures.Herein,we design an Fe-Ov-Ce-triggered phase-reversible CeO_(2)−x·Fe·CaO↔CeO_(2)·Ca_(2)Fe_(2)O_(5)oxygen carrier with strong electron-donating ability,which activates CO_(2)at low temperatures and promotes oxygen transformation.Results reveal that the maximum CO_(2)conversion and CO yield obtained with 50 mol%CeO_(2)−x·Fe·CaO are,respectively,426%and 53.6 times higher than those of Fe·CaO at 700℃.This unique multiphase material also retains exceptional redox durability,with no obvious deactivation after 100 splitting cycles.The addition of Ce promotes the formation of the Fe-Ov-Ce structure,which acts as an activator,triggers CO_(2)splitting,and lowers the energy barrier of C═O dissociation.The metallic Fe plays a role in consuming O_(2)−lattice transformed from Fe-Ov-Ce,whereas CaO acts as a structure promoter that enables phase-reversible Fe0↔Fe3+looping.展开更多
The integration of selective oxidation of renewable biomass and its derivatives with hydrogen(H_(2))pro-duction holds significant potential for simultaneously yielding value-added chemicals and“green H_(2)”,contribu...The integration of selective oxidation of renewable biomass and its derivatives with hydrogen(H_(2))pro-duction holds significant potential for simultaneously yielding value-added chemicals and“green H_(2)”,contributing to addressing sustainability challenges.The S-scheme charge transfer mechanism enhances charge separation by maintaining strong redox potentials at both ends,facilitating both oxidation and reduction reactions.Herein,we synthesize a visible-light-responsive oxygen vacancy-rich In_(2)O_(3-x)/tubular carbon nitride(IO_(OV)/TCN)S-scheme heterojunction photocatalyst via electrostatic adherence for selec-tive 5-hydroxymethylfurfural(HMF)oxidation to 2,5-diformylfuran(DFF)and 2,5-furandicarboxylic acid(FDCA),alongside H_(2)production.Under anaerobic conditions and visible-light irradiation,the optimal IOOV/TCN-10 catalyst achieves an HMF conversion of 94.8%with a selectivity of 53.6%for DFF and FDCA,and a H_(2)yield of 754.05μmol g^(−1)in 3 h.The significantly improved photocatalytic activity results from enhanced visible-light absorption,reduced carrier recombination,and abundant catalytic active sites due to the synergistic effect of surface oxygen vacancies,the hollow nanotube-based architecture,and the S-scheme charge transfer mechanism.This work highlights the great potentials of S-scheme heterojunctions in biomass conversion for sustainable energy use and chemical production.展开更多
The development of efficient photocatalysts for selective organic transformations under visible light remains a major challenge in sustainable chemistry.In this study,we present a straightforward solvothermal strategy...The development of efficient photocatalysts for selective organic transformations under visible light remains a major challenge in sustainable chemistry.In this study,we present a straightforward solvothermal strategy for fabricating a defect-engineered ZrO_(2)/UiO-66-NH_(2)hybrid material with abundant oxygen vacancies,enabling the visible-light-driven oxidation of benzyl alcohol to benzaldehyde.By optimizing the solvothermal treatment duration,the composite(UiO-66-NH_(2)-2h)achieves a 74.1%conversion of benzyl alcohol with>99%selectivity toward benzaldehyde under mild conditions,substantially out-performing pristine UiO-66-NH_(2).Structural and mechanistic studies reveal that the solvothermal process induces the in situ formation of ultrasmall,uniformly dispersed ZrO_(2)nanoparticles(~2.3 nm)within the MOF matrix,while simultaneously generating abundant oxygen vacancies,as confirmed by XPS,EPR,and HRTEM analyses.The defect-mediated electronic structure of the ZrO_(2)/UiO-66-NH_(2)hybrid enhances visible-light absorption,facilitates charge carrier separation,and pro-motes efficient activation of O_(2)into superoxide radicals(·O_(2)^(−)),the primary reactive species.Transient photocurrent measure-ments and electrochemical impedance spectroscopy further verify the improved charge separation efficiency.The synergistic interplay between oxygen vacancies and the intimate ZrO_(2)/UiO-66-NH_(2)interface provides a unique defect-mediated charge transfer pathway,distinguishing this system from conventional heterojunctions.This study demonstrates a facile,one-step approach to integrate defect engineering with interfacial hybridization in MOF-based photocatalysts,off ering a scalable route for solar-driven organic synthesis.展开更多
By manipulating the distribution of surface electrons,defect engineering enables effective control over the adsorption energy between adsorbates and active sites in the CO_(2)reduction reaction(CO_(2)RR).Herein,we rep...By manipulating the distribution of surface electrons,defect engineering enables effective control over the adsorption energy between adsorbates and active sites in the CO_(2)reduction reaction(CO_(2)RR).Herein,we report a hollow indium oxide nanotube containing both oxygen vacancy and sulfur doping(V_o-Sx-In_(2)O_(3))for improved CO_(2)-to-HCOOH electroreduction and Zn-CO_(2)battery.The componential synergy significantly reduces the*OCHO formation barrier to expedite protonation process and creates a favorable electronic micro-environment for*HCOOH desorption.As a result,the CO_(2)RR performance of Vo-Sx-In_(2)O_(3)outperforms Pure-In_(2)O_(3)and V_o-In_(2)O_(3),where V_o-S53-In_(2)O_(3)exhibits a maximal HCOOH Faradaic efficiency of 92.4%at-1,2 V vs.reversible hydrogen electrode(RHE)in H-cell and above 92%over a wide window potential with high current density(119.1 mA cm^(-2)at-1.1 V vs.RHE)in flow cell.Furthermore,the rechargeable Zn-CO_(2)battery utilizing V_o-S53-In_(2)O_(3)as cathode shows a high power density of 2.29 mW cm^(-2)and a long-term stability during charge-discharge cycles.This work provides a valuable perspective to elucidate co-defective catalysts in regulating the intermediates for efficient CO_(2)RR.展开更多
Concurrent activation of lattice oxygen(O_L)and molecular oxygen(O_(2))is crucial for the efficient catalytic oxidation of biomass-derived molecules over metal oxides.Herein,we report that the introduction of ultralow...Concurrent activation of lattice oxygen(O_L)and molecular oxygen(O_(2))is crucial for the efficient catalytic oxidation of biomass-derived molecules over metal oxides.Herein,we report that the introduction of ultralow-loading of Ru single atoms(0.42 wt%)into Mn_(2)O_(3)matrix(0.4%Ru-Mn_(2)O_(3))greatly boosts its catalytic activity for the aerobic oxidation of 5-hydroxymethylfurfural(HMF)to 2,5-furandicarboxylic acid(FDCA).The FDCA productivity over the 0.4%Ru-Mn_(2)O_(3)(5.4 mmol_(FDCA)g_(cat)h^(-1))is 4.9 times higher than the Mn_(2)O_(3).Especially,this FDCAproductivity is also significantly higher than that of existing Ru and Mn-based catalysts.Experimental and theoretical investigations discovered that the Ru single atom facilitated the formation of oxygen vacancy(O_(v))in the catalyst,which synergistically weakened the Mn-O bond and promoted the activation of O_L.The co-presence of Ru single atoms and O_(v)also promote the adsorption and activation of both O_(2)and HMF.Consequently,the dehydrogenation reaction energy barrier of the rate-determining step was reduced via both the O_L and chemisorbed O_(2)dehydrogenation pathways,thus boosting the catalytic oxidation reactions.展开更多
Natural biomass-derived carbon material is one promising alternative to traditional graphene-based catalyst for oxygen electrocatalysis.However,their electrocatalytic performance were constrained by the limited modula...Natural biomass-derived carbon material is one promising alternative to traditional graphene-based catalyst for oxygen electrocatalysis.However,their electrocatalytic performance were constrained by the limited modulating strategy.Herein,using N-doped commercial coconut shell-derived activated carbon(AC)as catalyst model,the controllably enhanced sp^(2)-C domains,through an flash Joule heating process,effectively improve the edge defect density and overall graphitization degree of AC catalyst,which tunes the electronic structure of N configurations and accelerates electron transfer,leading to excellent oxygen reduction reaction performance(half-wave potential of 0.884 VRHE,equivalent to commercial 20%Pt/C,with a higher kinetic current density of 5.88 mA cm^(−2))and oxygen evolution reaction activity(overpotential of 295 mV at 10 mA cm^(2)).In a Zn-air battery,the catalyst shows outstanding cycle stability(over 1200 h)and a peak power density of 121 mW cm^(−2),surpassing commercial Pt/C and RuO_(2)catalysts.Density functional theory simulation reveals that the enhanced catalytic activity arises from the axial regulation of local sp^(2)-C domains.This work establishes a robust strategy for sp^(2)-C domain modulation,offering broad applicability in natural biomass-based carbon catalysts for electrocatalysis.展开更多
Transition metal oxides(TMOs),thanks to their elevated theoretical capacitance and pseudocapacitive properties,are of particular interest in exploring the advanced supercapacitor electrode materials.The present work r...Transition metal oxides(TMOs),thanks to their elevated theoretical capacitance and pseudocapacitive properties,are of particular interest in exploring the advanced supercapacitor electrode materials.The present work reports the rapid laser-assisted synthesis of SiC@-Fe_(2)O_(3-x)anode materials with engineered oxygen vacancies in seconds,which improve the charge transport,redox activity,and structural stability,thus facilitating a substantial enhancement in electrochemical performance.As a result,the resultant SiC@Fe_(2)O_(3-x)nanowires exhibit excellent performances with an areal capacitance of 1082.16 at 5 mA cm^(-2),and retain 86.7%capacitance over 10,000 cycles.Furthermore,the assembled asymmetric supercapacitors(ASC),employing SiC@Fe_(2)O_(3-x)as the negative electrode and Ni(OH)2as the positive electrode,delivers a 1.5 V operating voltage,an energy density of 197μWh cm^(-2),and 80.6%capacitance retention after 14,000cycles,representing their promise toward the applications in next-generation energy storage materials.展开更多
This work is devoted to the development of a low cost dimensionally stable anode with high oxygen evolution catalytic activity for practical applications.For this purpose,a Ti/SnO_(x)/MnO_(2) anode was fabricated thro...This work is devoted to the development of a low cost dimensionally stable anode with high oxygen evolution catalytic activity for practical applications.For this purpose,a Ti/SnO_(x)/MnO_(2) anode was fabricated through an innovative strategy involving Sn electrodeposition,oxidation,and MnO_(2)-layer preparation.The structure of the anode was characterized,and the oxygen evolution performance was evaluated in a H_(2)SO_(4) solution.The results show that compared with the Ti/SnO_(2)/MnO_(2) anode prepared by the conventional brushing-annealing process,the Ti/SnO_(x)/MnO_(2) anode fabricated through the innovative procedure exhibits a lower oxygen evolution potential and a nearly 40%longer accelerated lifespan.The superior oxygen evolution performance of the Ti/SnO_(x)/MnO_(2) anode is attributed to the distinctive SnO_(x) intermediate layer fabricated through Sn electrodeposition followed by oxidation,which indicates the great potential of the anode as a dimensionally stable anode for metal electrowinning and hydrogen production by electrolysis,etc.展开更多
Conversion of CO_(2)back to hydrocarbons is the most direct way of closing the“carbon cycle”,and its significance is further enlarged if this process is driven by renewable energies such as electricity.However,preci...Conversion of CO_(2)back to hydrocarbons is the most direct way of closing the“carbon cycle”,and its significance is further enlarged if this process is driven by renewable energies such as electricity.However,precisely controlling the product selectivity towards hydrocarbons against the competitive hydrogen evolution remains challenging,especially for Cu-based catalysts.Herein,we report a novel defect engineering strategy,by which Cu-doping-induced oxygen vacancies on CeO_(2)nanorods were effectively created,with adjustable vacancy/Cu ratio.The resulting optimum catalyst shows up to 79%catalytic current density to hydrocarbons(excluding CO),with 49%faradaic efficiency to CH4.Experiments and density functional theory unveil that the ratio between oxygen vacancy and Cu affects significantly the formation of*CHO and activation of H2O,which leads to the following deep hydrogenation to hydrocarbons.These findings may spur new insights for designing and developing more controllable chemical process relevant to CO_(2)utilization.展开更多
基金financial supports from the National Natural Science Foundation of China(52201237)the Talent Introduction Project of Chinese Academy of Sciences(E344011)+4 种基金the Shenzhen High Level Talent Team Project(KQTD2022110109364705)the Joint Research Project of China Merchants Group and SIAT(E2Z1521)the Cross Institute Joint Research Youth Team Project of SIAT(E25427)National Natural Science Foundation of China(52402136)the China Postdoctoral Science Foundation(E325281005)。
文摘Electrocatalytic CO_(2)reduction(ECR)to produce value-added fuels and chemicals using renewable electricity is an emerging strategy to mitigate global warming and decrease reliance on fossil fuels.Among various ECR products,liquid oxygenates(Oxys)are especially attractive due to their high energy density,high safety and transportability that could be adapted to the existing infrastructure and transportation system.However,efficiently generating these highly reduced oxygen-containing products by ECR remains challenging due to the complexity of coupled proton and electron transfer processes.In recent years,in-depth studies of reaction mechanisms have advanced the design of catalysts and the regulation of reaction systems for ECR to produce Oxys,Here,by focusing on the production of typical Oxys,such as methanol,acetic acid,ethanol,acetone,n-propanol,and isopropanol,we outline various reaction paths and key intermediates for the electrochemical conversion of CO_(2)into these target products.We also summarize the current research status and recent advances in catalysts based on their elemental composition,and consider recent studies on the change of catalyst geometry and electronic structure,as well as the optimization of reaction systems to increase ECR performance.Finally,we analyze the challenges in the field of ECR to Oxys and provide an outlook on future directions for high-efficiency catalyst prediction and design,as well as the development of advanced reaction systems.
基金supported by National Natural Science Foundation of China(22379059)Applied Basic Research Program Project of Liaoning Province(2023JH2/101300224)+4 种基金Service Local Project of the Education Department of Liaoning Province(Enlisting and Leading)(LJKFZ20220201)General Project of the Educational Department of Liaoning Province(LJKMZ20220728)supported by Talent Scientific Research Fund of Liaoning Petrochemical University(2019-XJJL-028)Collaborative Innovation Project of Beijing-Tianjin-Hebei(Tianjin)(22PTXTHZ00020)Basic scientific research project of Liaoning Provincial Department of Education(LJ212410148019)。
文摘The adsorption of CO on different lattice oxygen sites in Cu doped CeO_(2)(111)was studied by DFT method,and the geometrical structure and electronic properties of adsorption systems were analyzed.The results showed that CO interacted with lattice oxygen on the first layer formed CO_(2).However,when adsorbed on the second layer lattice oxygen,carbonate species were formed with the participation of first layer lattice oxygens,i.e.,CO co-adsorbed on first and second layer lattice oxygens.For the second layer adsorption,the absolute CO adsorption energy was big on the Oss nearby Cu.This kind of carbonates was thermodynamically stable,and it was attributed to the facilitation of Cu on CO adsorption,manifested by an electron migration behavior from the C 2p orbitals to the Cu 3d orbitals.However,the absolute CO adsorption energy on the Oss away from Cu was small.Compared to the formation of carbonates,the formation CO_(2)had very small absolute adsorption energy,suggesting the formed carbonates on second layer was stable.Further,when CO adsorbed on the systems with a carbonate,the absolute CO adsorption energy was significantly smaller than that of the non-carbonated system,indicating that the formation of carbonates inhibited CO oxidation on Cu/CeO_(2)(111).Therefore,the formation of carbonates was unfavorable for CO oxidation reaction on Cu/CeO_(2)(111).The results of this study provide theoretical support for the negative effect of CO_(2)on ceria-based catalysts.
基金National Key Research and Development Program of China(2020YFA0710302)The Major Research Plan of the National Natural Science Foundation of China(91963206)+2 种基金The National Natural Science Foundation of China(52072169,51972164,51972167,22279053)The Fundamental Research Funds for the Central Universities(14380193)The Program for Guangdong Introducing Innovative and Entrepreneurial Teams(2019ZT08L101).
文摘On the surfaces of celestial bodies with no or thin atmospheres,such as the Moon and Mars,the solar wind irradiation process leads to the formation of hydrogen and helium enriched regions in the extraterrestrial soil particles.However,soil particles on the Earth with the similar composition lack such structures and properties.This discrepancy raises a key question whether there is a direct relationship between solar wind irradiation and the alterations in the structure and chemical performance of extraterrestrial materials.To address this question,this work investigates the effects of proton irradiation,simulating solar wind radiation,on the structure and photothermal catalytic properties of the classic catalyst In_(2)O_(3).It reveals that proton irradiation induces structural features in In_(2)O_(3) analogous to those characteristics of solar wind weathering observed in extraterrestrial materials.Furthermore,after proton beam irradiation with an energy of 30 keV and a dose of 3×10^(17) protons·cm^(-2),the methanol production yield of the In_(2)O_(3) catalyst increased to 2.6 times of its preirradiation level,and the methanol selectivity improved to 2.1 times of the original value.This work provides both theoretical and experimental support for the development of high-efficiency,radiation-resistant photothermal catalysts.
基金Research Project of Shenzhen Science and Technology Innovation Committee(JCYJ20180306170801080)。
文摘Amorphous Ga_(2)O_(3)(a-Ga_(2)O_(3))thin films were prepared on flexible polyimide,rigid quartz glass,and Si substrates via radio frequency magnetron sputtering at room temperature.The effect of oxygen/Ar flow rate ratio on the structure,optical property,surface morphology,and chemical bonding properties of the a-Ga_(2)O_(3) films was investigated.Results show that the average optical transmittance of the a-Ga_(2)O_(3) films is over 80%within the wavelength range of 300-2000 nm.The extracted optical band gap of the a-Ga_(2)O_(3) films is increased from 4.97 eV to 5.13 eV with the increase in O_(2)/Ar flow rate ratio from 0 to 0.25,due to the decrease in concentration of oxygen vacancy defects in the film.Furthermore,the optical refractive index and surface roughness of the a-Ga_(2)O_(3) films are optimized when the O_(2)/Ar flow rate ratio reaches 0.25.X-ray photoelectron spectroscopy analysis also shows that the proportion of oxygen vacancies(VO)and Ga-O chemical bonds in the O 1s peak is gradually decreased with the increase in O_(2)/Ar flow rate ratio from 0 to 0.25,proving that increasing the O_(2)/Ar flow rate ratio during film growth can reduce the concentration of oxygen vacancy defects in a-Ga_(2)O_(3) films.In this case,a-Ga_(2)O_(3) with optimal properties can be obtained.This work provides a research basis for high-performance flexible and rigid deep ultraviolet solar-blind detection devices based on a-Ga_(2)O_(3) films.
文摘The oxygen evolution reaction(OER)serves as a fundamental half–reaction in the electrolysis of water for hydrogen production,which is restricted by the sluggish OER reaction kinetics and unable to be practically applied.The traditional lattice oxygen oxidation mechanism(LOM)offers an advantageous route by circumventing the formation of M-OOH^(*)in the adsorption evolution mechanism(AEM),thus enhancing the reaction kinetics of the OER but resulting in possible structural destabilization due to the decreased M–O bond order.Fortunately,the asymmetry of tetrahedral and octahedral sites in transition metal spinel oxides permits the existence of non-bonding oxygen,which could be activated by rational band structure design for direct O-O coupling,where the M–O bond maintains its initial bond order.Here,non-bonding oxygen was introduced into NiFe_(2)O_(4)via annealing in an oxygen-deficient atmosphere.Then,in-situ grown sulfate species on octahedral nickel sites significantly improved the reactivity of the non-bonding oxygen electrons,thereby facilitating the transformation of the redox center from metal to oxygen.LOM based on non-bonding oxygen(LOMNB)was successfully activated within NiFe_(2)O_(4),exhibiting a low overpotential of 206 mV to achieve a current density of 10 mA cm^(-2)and excellent durability of stable operation for over 150 h.Additionally,catalysts featuring varying band structures were synthesized for comparative analysis,and it was found that the reversible redox processes of non-bonding oxygen and the accumulation of non-bonding oxygen species containing 2p holes are critical prerequisites for triggering and sustaining the LOMNB pathway in transition metal spinel oxides.These findings may provide valuable insights for the future development of spinel-oxide-based LOM catalysts.
基金supported by the Natural Science Foundation of China(Nos.22278094 and 22379033)Guangdong Graduate Education Innovation Program(No.2023JGXM_102)+2 种基金the Basic and Applied Basic Research Program of Guangzhou(No.SL2024A03J00499)the University Innovation Team Scientific Research Project of Guangzhou(No.202235246)Hainan Province Graduate Innovation Research Project(No.Qhyb2023-143).
文摘Four-electron oxygen evolving reaction is limited by proton adsorption and desorption,making its reaction kinetics sluggish,which poses a major challenge for catalyst design.Here,we present an unsaturated coordination interface by constructing a fast electron transfer channel between Cu_(2)V_(2)O_(7)(CVO)and BiVO4(BVO).X-ray absorption spectroscopy(XAS)and theoretical calculations results confirm that CVO and BVO between interfaces are bonded by the way of unsaturated coordination oxygen(Ouc).The Ouc optimizes the O-O coupled energy barrier at the V active site and promotes the disconnection of O-H bond,which increases the photocurrent intensity of CVO by 6 times.In addition,due to the high electronegativity of the Ouc,the bonding energies of Bi-O and Cu-O at the interface are enhanced,resulting in the long-term stability of the photoanode during the water splitting.Finally,by integrating the working electrode with a polysilicon solar cell,we assembled a device that demonstrated exceptional catalytic performance,achieving a hydrogen production rate of 100.6μmol·cm^(-2),and maintaining a hydrogen-to-oxygen volume ratio of 2:1 after continuous operation for 4 h.This discovery aids in a deeper understanding of photoanode design and offers further insights for industrial applications.
基金the financial support from the European Commission through the H2020-MSCA-RISE-2020 BIOALL project(Grant Agreement: 101008058)。
文摘Single carbon products(C1 compounds) are simple but important chemicals in the road towards energy transition.Catalytic conversion of CO_(2) with H_(2)(desirably renewable) can be performed over reducible oxides supporting transition metals to obtain products such as CH_(4),CO and MeOH.Oxygen vacancies(O-vacancies),which are inherent defects of reducible metal oxides,play an enormous role in driving the catalytic performance(activity,selectivity,stability) for the desired reactions.Yet,the assessment of O-defects at realistic conditions is often complex.Only few techniques can provide direct evidence for their existence and influence in CO_(2) activation.Among them,electron paramagnetic spectroscopy(EPR),Raman spectroscopy,scanning probe microscopies(SPM) and environmental transmission electron microscopy(ETEM) are nowadays the most informative.In most cases,however,the measurements require reaction conditions far away from CO_(2) valorization applications.Although great efforts have been fruitful in explaining and demonstrating the huge importance of O-vacancies in CO_(2) catalysis,still ambiguous or erroneous interpretations about structure-function correlations involving O-vacancies are found in literature,especially,when information is not properly gathered,e.g.,by O 1s ex-situ X-ray photon spectroscopy(XPS).Moreover,despite the recognized importance of O-vacancies for CO_(2) valorization,critical literature compilations about their effects in thermal processes are scarce.Herein,we attempt to contribute in closing this gap by integrally encompassing representative investigations on the thermo-catalytic production of CH_(4),CO and MeOH.Particularly,we emphasize on the proper selection of assessment tools(direct/indirect) to unambiguously establish structure-function relationships to design optimized O-defective catalysts for the targeted compounds.
基金funded by the National Natural Science Foundation of China(Nos.22179098 and 22209153).
文摘Despite its high capacity behavior as the anode for lithium-ion batteries (LIBs), SnO_(2) suffers the poorelectronic conductivity and high volume expansion, which lead to poor cycling stability and rate capability. In this study, we employ defect engineering to design SnO_(2−x)(x = 0, 0.12, 0.2, and 0.3) nanoparticleswith varied oxygen vacancies. Notably, the SnO1.80 electrode with 20 % oxygen vacancies exhibits excellent electrochemical performance. Advanced physical characterizations combined with density functionaltheory (DFT) simulations demonstrate that the improved electrochemical performance can be attributedto the formation of a stable, uniform, and LiF-rich solid-electrolyte interface (SEI) layer through the optimization of oxygen vacancies. This study shows novel insights into the application of defect engineeringwithin oxides for the rational design of the uniform surface layer toward high-energy-density LIBs.
基金funding support from the National Natural Science Foundation of China(5237122722002068+8 种基金52272222,and 52072197)the Taishan Scholar Young Talent Program(tsqn201909114)the Shandong Province“Double-Hundred Talent Plan”(WST2020003)the Youth Innovation and Technology Foundation of Shandong Higher Education Institutions,China(2019KJC004)the Outstanding Youth Foundation of Shandong Province,China(ZR2019JQ14)the Major Basic Research Program of Natural Science Foundation of Shandong Province under Grant No.ZR2020ZD09the Major Scientific and Technological Innovation Project(2019JZZY020405)the University Youth Innovation Team of Shandong Province(202201010318)the Youth Innovation Team Development Program of Shandong Higher Education Institutions(2022KJ155)。
文摘A hydrogen spillover-bridged water dissociation/hydrogen formation could concurrently promote Volmer/Tafel process and improve the efficiency of hydrogen evolution reaction(HER)under alkaline conditions.However,it is still challenging to promote occurrence of hydrogen spillover for the large interfacial transport barriers of H_(2)O and hydrogen on active sites.Herein,the strategy of energy barrier gradient to induce hydrogen spillover was proposed by constructing Ru nanoclusters coupled with single atom onto oxygen vacancy cerium dioxide(Ru/CeO_(2)-Ov-2).Density functional theory(DFT)calculations uncover that the adsorption/desorption of H2O occurs at the Ru clusters sites and then the dissociated H*spontaneously overflows from Ru clusters with high binding energy into the adjacent Ru single atom sites with low binding energy,which facilitate the hydrogen formation.Consequently,the synthesized Ru/CeO_(2)-Ov-2 exhibits a small overpotential of 41 mV at 10 mA cm^(-2)and good stability at 500 mA cm^(-2)for 100 h in alkaline seawater,which could be ascribed to the rapid hydrogen spillover and strong coupling interaction between Ru and CeO_(2)-O_(v).This work provides a novel insight that synthesizing cooperative sites with energy barrier gradient helps to promote hydrogen spillover and accelerate the Volmer/Tafel process of HER.
文摘Although defect engineering has been widely used to boost catalytic CO_(2) photoreduction,the piezoelectric polarized properties induced by structure changes through introducing defects are always ignored.Here we report a new kind of bismuth oxybromide(BiOBr,BOB)with piezoelectric property regulated by oxygen vacancies(OVs).Compared with pure BOB,BOB with OVs(BOB-OV)could enhance photocatalytic CO_(2) reduction efficiency under the ultrasonic force,achieving durable CO_(2) reduction process to superior production rates of CO(54.4μmol g^(-1) h^(-1))with a high selectivity(92%).Moderate OVs concentration changed the degree of Bi-Br stretching in the BOB-OV to produce strong dipole moments,which endowed BOB-OV with strong spontaneous piezoelectric polarization ability under external force.Ultrasonic piezoelectric effects were innovatively integrated into the photocatalytic reaction,which not only provided an alternating force field to modulate the spontaneous polarization of BOB-OV,thereby maintaining efficient photogenerated charge separation,but also lowered the reaction energy barrier of CO_(2) by high stress,ultimately improving CO product selectivity.This study is the first to leverage OVs-induced piezoelectric polarization effects to enhance the performance and product selectivity of photocatalytic CO_(2) reduction,providing new directions and insights for defect engineering to contribute to photocatalysis.
基金supported by the National Natural Science Foundation of China(21832005,22072168,22002175)Major Program of the Lanzhou Institute of Chemical Physics,CAS(No.ZYFZFX-3)+1 种基金Major Science and Technology Projects in Gansu Province(22ZD6GA003)West Light Foundation of The Chinese Academy of Sciences(xbzg-zdsys-202209).
文摘Artificial carbon fixation is a promising pathway for achieving the carbon cycle and environment remediation.However,the sluggish kinetics of oxygen evolution reaction(OER)and poor selectivity of CO_(2) reduction seriously limited the overall conversion efficiencies of solar energy to chemical fuels.Herein,we demonstrated a facile and feasible strategy to rationally regulate the coordination environment and electronic structure of surface-active sites on both photoanode and cathode.More specifically,the defect engineering has been employed to reduce the coordination number of ultrathin FeNi catalysts decorated on BiVO4 photoanodes,resulting in one of the highest OER activities of 6.51 mA cm^(−2)(1.23 VRHE,AM 1.5G).Additionally,single-atom cobalt(II)phthalocyanine anchoring on the N-rich carbon substrates to increase Co–N coordination number remarkably promotes CO_(2) adsorption and activation for high selective CO production.Their integration achieved a record activity of 109.4μmol cm^(−2) h−1 for CO production with a faradaic efficiency of>90%,and an outstanding solar conversion efficiency of 5.41%has been achieved by further integrating a photovoltaic utilizing the sunlight(>500 nm).
基金supported by the National Key R&D Program of China(2022YFE0105900)the National Natural Science Foundation of China(52436006,52476144,52311530339,42441835)the Innovation-Driven Project of Central South University(2023ZZTS0721).
文摘Advanced oxygen carrier plays a pivotal role in various chemical looping processes,such as CO_(2)splitting.However,oxygen carriers have been restricted by deactivation and inferior oxygen transferability at low temperatures.Herein,we design an Fe-Ov-Ce-triggered phase-reversible CeO_(2)−x·Fe·CaO↔CeO_(2)·Ca_(2)Fe_(2)O_(5)oxygen carrier with strong electron-donating ability,which activates CO_(2)at low temperatures and promotes oxygen transformation.Results reveal that the maximum CO_(2)conversion and CO yield obtained with 50 mol%CeO_(2)−x·Fe·CaO are,respectively,426%and 53.6 times higher than those of Fe·CaO at 700℃.This unique multiphase material also retains exceptional redox durability,with no obvious deactivation after 100 splitting cycles.The addition of Ce promotes the formation of the Fe-Ov-Ce structure,which acts as an activator,triggers CO_(2)splitting,and lowers the energy barrier of C═O dissociation.The metallic Fe plays a role in consuming O_(2)−lattice transformed from Fe-Ov-Ce,whereas CaO acts as a structure promoter that enables phase-reversible Fe0↔Fe3+looping.
基金financially supported by the Natural Science Foundation of China(Nos.21972058,22102064,and 22302080)Anhui Key Laboratory of Nanomaterials and Nanotechnology,the Major Science and Technology Projects in Anhui Province(No.202305a12020006).
文摘The integration of selective oxidation of renewable biomass and its derivatives with hydrogen(H_(2))pro-duction holds significant potential for simultaneously yielding value-added chemicals and“green H_(2)”,contributing to addressing sustainability challenges.The S-scheme charge transfer mechanism enhances charge separation by maintaining strong redox potentials at both ends,facilitating both oxidation and reduction reactions.Herein,we synthesize a visible-light-responsive oxygen vacancy-rich In_(2)O_(3-x)/tubular carbon nitride(IO_(OV)/TCN)S-scheme heterojunction photocatalyst via electrostatic adherence for selec-tive 5-hydroxymethylfurfural(HMF)oxidation to 2,5-diformylfuran(DFF)and 2,5-furandicarboxylic acid(FDCA),alongside H_(2)production.Under anaerobic conditions and visible-light irradiation,the optimal IOOV/TCN-10 catalyst achieves an HMF conversion of 94.8%with a selectivity of 53.6%for DFF and FDCA,and a H_(2)yield of 754.05μmol g^(−1)in 3 h.The significantly improved photocatalytic activity results from enhanced visible-light absorption,reduced carrier recombination,and abundant catalytic active sites due to the synergistic effect of surface oxygen vacancies,the hollow nanotube-based architecture,and the S-scheme charge transfer mechanism.This work highlights the great potentials of S-scheme heterojunctions in biomass conversion for sustainable energy use and chemical production.
基金the National Natural Sci-ence Foundation of China(Nos.22271038,22378038,22172012)C.P.thanks Dalian Science and Technology Innovation Fund(No.2024JJ12CG033)+1 种基金C.P.and Z.S thank State Key Laboratory of Heavy Oil Processing(Nos.WX20230149,SKLHOP202402005)Y.-Y.L.thanks the Guangxi Key Laboratory of Information Materials,Guilin University of Electronic Technology(No.231019-K).
文摘The development of efficient photocatalysts for selective organic transformations under visible light remains a major challenge in sustainable chemistry.In this study,we present a straightforward solvothermal strategy for fabricating a defect-engineered ZrO_(2)/UiO-66-NH_(2)hybrid material with abundant oxygen vacancies,enabling the visible-light-driven oxidation of benzyl alcohol to benzaldehyde.By optimizing the solvothermal treatment duration,the composite(UiO-66-NH_(2)-2h)achieves a 74.1%conversion of benzyl alcohol with>99%selectivity toward benzaldehyde under mild conditions,substantially out-performing pristine UiO-66-NH_(2).Structural and mechanistic studies reveal that the solvothermal process induces the in situ formation of ultrasmall,uniformly dispersed ZrO_(2)nanoparticles(~2.3 nm)within the MOF matrix,while simultaneously generating abundant oxygen vacancies,as confirmed by XPS,EPR,and HRTEM analyses.The defect-mediated electronic structure of the ZrO_(2)/UiO-66-NH_(2)hybrid enhances visible-light absorption,facilitates charge carrier separation,and pro-motes efficient activation of O_(2)into superoxide radicals(·O_(2)^(−)),the primary reactive species.Transient photocurrent measure-ments and electrochemical impedance spectroscopy further verify the improved charge separation efficiency.The synergistic interplay between oxygen vacancies and the intimate ZrO_(2)/UiO-66-NH_(2)interface provides a unique defect-mediated charge transfer pathway,distinguishing this system from conventional heterojunctions.This study demonstrates a facile,one-step approach to integrate defect engineering with interfacial hybridization in MOF-based photocatalysts,off ering a scalable route for solar-driven organic synthesis.
基金supported by the Fundamental Research Funds for the Central Universities(22120230104).
文摘By manipulating the distribution of surface electrons,defect engineering enables effective control over the adsorption energy between adsorbates and active sites in the CO_(2)reduction reaction(CO_(2)RR).Herein,we report a hollow indium oxide nanotube containing both oxygen vacancy and sulfur doping(V_o-Sx-In_(2)O_(3))for improved CO_(2)-to-HCOOH electroreduction and Zn-CO_(2)battery.The componential synergy significantly reduces the*OCHO formation barrier to expedite protonation process and creates a favorable electronic micro-environment for*HCOOH desorption.As a result,the CO_(2)RR performance of Vo-Sx-In_(2)O_(3)outperforms Pure-In_(2)O_(3)and V_o-In_(2)O_(3),where V_o-S53-In_(2)O_(3)exhibits a maximal HCOOH Faradaic efficiency of 92.4%at-1,2 V vs.reversible hydrogen electrode(RHE)in H-cell and above 92%over a wide window potential with high current density(119.1 mA cm^(-2)at-1.1 V vs.RHE)in flow cell.Furthermore,the rechargeable Zn-CO_(2)battery utilizing V_o-S53-In_(2)O_(3)as cathode shows a high power density of 2.29 mW cm^(-2)and a long-term stability during charge-discharge cycles.This work provides a valuable perspective to elucidate co-defective catalysts in regulating the intermediates for efficient CO_(2)RR.
基金financially supported by National Natural Science Foundation of China(22208137 and 22068022)Yunnan Fundamental Research Projects(202101BE070001-033,202401AT070825,202201BE070001007 and 202301AV070005)。
文摘Concurrent activation of lattice oxygen(O_L)and molecular oxygen(O_(2))is crucial for the efficient catalytic oxidation of biomass-derived molecules over metal oxides.Herein,we report that the introduction of ultralow-loading of Ru single atoms(0.42 wt%)into Mn_(2)O_(3)matrix(0.4%Ru-Mn_(2)O_(3))greatly boosts its catalytic activity for the aerobic oxidation of 5-hydroxymethylfurfural(HMF)to 2,5-furandicarboxylic acid(FDCA).The FDCA productivity over the 0.4%Ru-Mn_(2)O_(3)(5.4 mmol_(FDCA)g_(cat)h^(-1))is 4.9 times higher than the Mn_(2)O_(3).Especially,this FDCAproductivity is also significantly higher than that of existing Ru and Mn-based catalysts.Experimental and theoretical investigations discovered that the Ru single atom facilitated the formation of oxygen vacancy(O_(v))in the catalyst,which synergistically weakened the Mn-O bond and promoted the activation of O_L.The co-presence of Ru single atoms and O_(v)also promote the adsorption and activation of both O_(2)and HMF.Consequently,the dehydrogenation reaction energy barrier of the rate-determining step was reduced via both the O_L and chemisorbed O_(2)dehydrogenation pathways,thus boosting the catalytic oxidation reactions.
基金supported by National Natural Science Foundation of China (No. 32371810)China Postdoctoral Science Foundation (2023M731702)+5 种基金National Key Research and Development Program of China (2023YFB4203702)the Foundation Research Project of Jiangsu Province (BK20221338)Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest ResourcesInternational Innovation Center for Forest Chemicals and Materials,Nanjing Forestry Universitymerit-based funding for Nanjing innovation and technology projectsthe Foundation of Jiangsu Key Lab of Biomass Energy and Material (JSBEM-S-202101)
文摘Natural biomass-derived carbon material is one promising alternative to traditional graphene-based catalyst for oxygen electrocatalysis.However,their electrocatalytic performance were constrained by the limited modulating strategy.Herein,using N-doped commercial coconut shell-derived activated carbon(AC)as catalyst model,the controllably enhanced sp^(2)-C domains,through an flash Joule heating process,effectively improve the edge defect density and overall graphitization degree of AC catalyst,which tunes the electronic structure of N configurations and accelerates electron transfer,leading to excellent oxygen reduction reaction performance(half-wave potential of 0.884 VRHE,equivalent to commercial 20%Pt/C,with a higher kinetic current density of 5.88 mA cm^(−2))and oxygen evolution reaction activity(overpotential of 295 mV at 10 mA cm^(2)).In a Zn-air battery,the catalyst shows outstanding cycle stability(over 1200 h)and a peak power density of 121 mW cm^(−2),surpassing commercial Pt/C and RuO_(2)catalysts.Density functional theory simulation reveals that the enhanced catalytic activity arises from the axial regulation of local sp^(2)-C domains.This work establishes a robust strategy for sp^(2)-C domain modulation,offering broad applicability in natural biomass-based carbon catalysts for electrocatalysis.
基金financially supported by the National Natural Science Foundation of China(No.52372063)China Postdoctoral Science Foundation(No.2023M730391)
文摘Transition metal oxides(TMOs),thanks to their elevated theoretical capacitance and pseudocapacitive properties,are of particular interest in exploring the advanced supercapacitor electrode materials.The present work reports the rapid laser-assisted synthesis of SiC@-Fe_(2)O_(3-x)anode materials with engineered oxygen vacancies in seconds,which improve the charge transport,redox activity,and structural stability,thus facilitating a substantial enhancement in electrochemical performance.As a result,the resultant SiC@Fe_(2)O_(3-x)nanowires exhibit excellent performances with an areal capacitance of 1082.16 at 5 mA cm^(-2),and retain 86.7%capacitance over 10,000 cycles.Furthermore,the assembled asymmetric supercapacitors(ASC),employing SiC@Fe_(2)O_(3-x)as the negative electrode and Ni(OH)2as the positive electrode,delivers a 1.5 V operating voltage,an energy density of 197μWh cm^(-2),and 80.6%capacitance retention after 14,000cycles,representing their promise toward the applications in next-generation energy storage materials.
文摘This work is devoted to the development of a low cost dimensionally stable anode with high oxygen evolution catalytic activity for practical applications.For this purpose,a Ti/SnO_(x)/MnO_(2) anode was fabricated through an innovative strategy involving Sn electrodeposition,oxidation,and MnO_(2)-layer preparation.The structure of the anode was characterized,and the oxygen evolution performance was evaluated in a H_(2)SO_(4) solution.The results show that compared with the Ti/SnO_(2)/MnO_(2) anode prepared by the conventional brushing-annealing process,the Ti/SnO_(x)/MnO_(2) anode fabricated through the innovative procedure exhibits a lower oxygen evolution potential and a nearly 40%longer accelerated lifespan.The superior oxygen evolution performance of the Ti/SnO_(x)/MnO_(2) anode is attributed to the distinctive SnO_(x) intermediate layer fabricated through Sn electrodeposition followed by oxidation,which indicates the great potential of the anode as a dimensionally stable anode for metal electrowinning and hydrogen production by electrolysis,etc.
基金National Natural Science Foundation of China(21968020,22302222)Natural Science Foundation of Inner Mongolia(2022MS02011)+3 种基金China Postdoctoral Science Foundation under Grant Number(2024T170965,2023M743641)Science and Technology Projects of China Northern Rare Earth(BFXT-2022-D-0023)Science and Technology Department of Shanxi Province(202303021222409)Education Department of Inner Mongolia Autonomous Region(NJZZ23094,NJYT23039)。
文摘Conversion of CO_(2)back to hydrocarbons is the most direct way of closing the“carbon cycle”,and its significance is further enlarged if this process is driven by renewable energies such as electricity.However,precisely controlling the product selectivity towards hydrocarbons against the competitive hydrogen evolution remains challenging,especially for Cu-based catalysts.Herein,we report a novel defect engineering strategy,by which Cu-doping-induced oxygen vacancies on CeO_(2)nanorods were effectively created,with adjustable vacancy/Cu ratio.The resulting optimum catalyst shows up to 79%catalytic current density to hydrocarbons(excluding CO),with 49%faradaic efficiency to CH4.Experiments and density functional theory unveil that the ratio between oxygen vacancy and Cu affects significantly the formation of*CHO and activation of H2O,which leads to the following deep hydrogenation to hydrocarbons.These findings may spur new insights for designing and developing more controllable chemical process relevant to CO_(2)utilization.
