Fenton technology has garnered significant attention for the deep removal of low-concentration emerging contaminants due to its remarkable oxidation performance.However,the traditional mineralization process for emerg...Fenton technology has garnered significant attention for the deep removal of low-concentration emerging contaminants due to its remarkable oxidation performance.However,the traditional mineralization process for emerging contaminants requires a substantial amount of hydroxyl radicals(HO˙),leading to excessive consumption of H_(2)O_(2).Through interfacial engineering of Fe-Zr bimetallic catalysts(FeZrO_(x)),this study demonstrates synergistic enhancement of phenolic pollutant removal at heterojunction interfaces while achieving an 80%reduction in H_(2)O_(2)dosage compared to traditional Fe_(2)O_(3)systems.The chemical states of Fe and Zr at the(104)/(111)heterojunction interface in FeZrO_(x)exhibit marked modifications relative to their monometallic Fe_(2)O_(3)and ZrO_(2)counterparts.The elevated charge density at interfacial Fe sites in FeZrO_(x)promotes HO˙generation,while optimized antibonding orbital composition below the Fermi level in bisphenol A adsorbed on Zr sites enhances hydrogen abstraction and subsequent polymerization.This Fe-Zr synergy at the(104)/(111)heterojunction concurrently suppresses HO˙diffusion losses and directs phenolic pollutant(e.g.,phenol and bisphenol A)polymerization within the reactive interface,thereby reducing H_(2)O_(2)consumption compared to monometallic systems.展开更多
Layered oxides present compelling potential as cathode materials for sodium-ion batteries(SIBs).However,challenges including interfacial instability and sluggish reaction kinetics critically limit their rate capabilit...Layered oxides present compelling potential as cathode materials for sodium-ion batteries(SIBs).However,challenges including interfacial instability and sluggish reaction kinetics critically limit their rate capability and cycling performance.Herein,we introduce the water-soluble sodium polyacrylate(NaPAA)binder as a promising approach to mitigating these issues in P2-type layered oxides.The NaPAA binder facilitates the formation of a uniform Na^(+) conductive interfacial film,which protects the cathode against electrolyte-induced corrosion and effectively inhibits the dissolution of transition metals in P2-Na_(0.85)Li_(0.12)Ni_(0.22)Mn_(0.66)O_(2)(NLNMO).Furthermore,we elucidate the mechanism by which the NaPAA binder dynamically regulates the coordination of free anions at the electrode-electrolyte interface.This regulation reduces solvent decomposition and promotes the formation of a stable,ionically conductive layer.Consequently,the P2-NLNMO@NaPAA integrated electrode exhibits enhanced electrochemical performance,achieving an 89.2%capacity retention after 200 cycles at 0.2 C and delivering an initial capacity of 102.9 mA h g^(-1) even at 0℃.This study advances the fundamental understanding of binder-mediated interface engineering and demonstrates a scalable and eco-friendly manufacturing pathway for high-performance SIBs.展开更多
The conversion of CO_(2) into high value added chemicals via the Fischer-Tropsch synthesis(FTS)reaction has attracted significant attention.The surface oxygenation environment is a significant factor influencing the p...The conversion of CO_(2) into high value added chemicals via the Fischer-Tropsch synthesis(FTS)reaction has attracted significant attention.The surface oxygenation environment is a significant factor influencing the performance of the catalyst.In this work,spin-polarized density-functional theory calculations have been used to investigate the adsorption and reactions of CO_(2) and H to generate CH4 and CH3OH on Fe_(5)C_(2)(100)surfaces with varying OH∗coverage.On the pure Fe_(5)C_(2)(100)surface,surface C^(∗) preferentially reacts with hydrogen to form CH4,exposing C^(∗) vacancy.CO_(2) favors adsorbing on the C^(∗) vacancy to further dissociating and activating.The co-adsorption of OH∗promotes the C^(∗) cycle process by facilitating the hydrogenation of C^(∗).The Fe_(5)C_(2) surface with an oxide interface is favorable for reducing FexOy,thereby maintaining the dynamic stability of the surface.Therefore,surface oxidation is inevitably involved in the entire C^(∗) cycle of the FTS reaction and regulates the relative content of iron oxides and iron carbides.Our work can contribute to the rational modulation of the surface C^(∗) cycle,thereby enhancing catalyst performance.展开更多
Some active metal oxides(Al_(2)O_(3),TiO_(2),and Cr_(2)O_(3))were selected as dopants to the Al_(2)O_(3)-based ceramic shells for investment casting of K417G superalloy.The effects of dopant types and contents(0,2,5,a...Some active metal oxides(Al_(2)O_(3),TiO_(2),and Cr_(2)O_(3))were selected as dopants to the Al_(2)O_(3)-based ceramic shells for investment casting of K417G superalloy.The effects of dopant types and contents(0,2,5,and 8 wt.%)on the wettability and interfacial reaction between the alloy and shell were investigated by a sessile-drop experiment.The results show that increasing the Al_(2)O_(3) doping contents(0−8 wt.%)reduces the porosity(21.74%−10.08%)and roughness(3.22−1.34μm)of the shell surface.The increase in Cr_(2)O_(3) dopant content(2−8 wt.%)further exacerbates the interfacial reaction,leading to an increase in the thickness of the reaction layer(2.6−3.1μm)and a decrease in the wetting angle(93.9°−91.0°).The addition of Al_(2)O_(3) and TiO_(2) dopants leads to the formation of Al_(2)TiO_(5) composite oxides in the reaction products,which effectively inhibits the interfacial reaction.The increase in TiO_(2) dopant contents(0−8 wt.%)further promotes the formation of Al_(2)TiO_(5),which decreases the thickness of the interfacial reaction layer(3.9−1.2μm)and increases the wetting angle(95.0°−103.8°).The introduced dopants enhance the packing density of the shell surface,while simultaneously suppress the diffusion of active metal elements from the alloy matrix to the interface.展开更多
In this study, a new facile preparation method of nanocomposites consisting of graphene oxide and manganese dioxide nanowires（GO/MnO2 NWs） was developed. The morphology, structure and composition of the resulted pro...In this study, a new facile preparation method of nanocomposites consisting of graphene oxide and manganese dioxide nanowires（GO/MnO2 NWs） was developed. The morphology, structure and composition of the resulted products were characterized by transmission electron microscopy, X-ray diffraction and N2 adsorption and desorption. The GO/MnO2 nanocomposite was used as an electrode material for non-enzymatic determination of hydrogen peroxide. The proposed sensor exhibits excellent electrocatalytic performance for the determination of hydrogen peroxide in phosphate buffer solution（PBS, pH7） at an applied potential of 0.75 V. The non-enzymatic biosensor for determination of hydrogen peroxide displayed a wide linear range of 4.90 mmol L^-1–4.50 mmol L^-1with a correlation coefficient of 0.9992, a low detection limit of 0.48 mmol L^-1 and a high sensitivity of 191.22μA（mmol L^-1）^-1cm^-2（signal/noise, S/N = 3）. Moreover, the non-enzymatic biosensor shows an excellent selectivity.展开更多
The Zn-Al spinel oxide stands out as one of the most active catalysts for high-temperature methanol synthesis from CO_(2)hydrogenation.However,the structure–activity relationship of the reaction remains poorly unders...The Zn-Al spinel oxide stands out as one of the most active catalysts for high-temperature methanol synthesis from CO_(2)hydrogenation.However,the structure–activity relationship of the reaction remains poorly understood due to challenges in atomic-level structural characterizations and analysis of reaction intermediates.In this study,we prepared two Zn-Al spinel oxide catalysts via coprecipitation(ZnAl-C)and hydrothermal(ZnAl-H)methods,and conducted a comparative investigation in the CO_(2)hydrogenation reaction.Surprisingly,under similar conditions,ZnAl-C exhibited significantly higher selectivity towards methanol and DME compared to ZnAl-H.Comprehensive characterizations using X-ray diffraction(XRD),Raman spectroscopy and electron paramagnetic resonance(EPR)unveiled that ZnAl-C catalyst had abundant ZnO species on its surface,and the interaction between the ZnO species and its ZnAl spinel oxide matrix led to the formation of oxygen vacancies,which are crucial for CO_(2)adsorption and activation.Additionally,state-of-the-art solid-state nuclear magnetic resonance(NMR)techniques,including ex-situ and in-situ NMR analyses,confirmed that the surface ZnO facilitates the formation of unique highly reactive interfacial formate species,which was readily hydrogenated to methanol and DME.These insights elucidate the promotion effects of ZnO on the ZnAl spinel oxide in regulating active sites and reactive intermediates for CO_(2)-to-methanol hydrogenation reaction,which is further evidenced by the significant enhancement in methanol and DME selectivity observed upon loading ZnO onto the ZnAl-H catalyst.These molecular-level mechanism understandings reinforce the idea of optimizing the ZnO-ZnAl interface through tailored synthesis methods to achieve activity-selectivity balance.展开更多
The rapid industrial growth and increasing population have led to significant pollution and deterioration of the natural atmospheric environment.Major atmospheric pollutants include NO_(2)and CO_(2).Hence,it is impera...The rapid industrial growth and increasing population have led to significant pollution and deterioration of the natural atmospheric environment.Major atmospheric pollutants include NO_(2)and CO_(2).Hence,it is imperative to develop NO_(2)and CO_(2)sensors for ambient conditions,that can be used in indoor air quality monitoring,breath analysis,food spoilage detection,etc.In the present study,two thin film nanocomposite(nickel oxide-graphene and nickel oxide-silver nanowires)gas sensors are fabricated using direct ink writing.The nano-composites are investigated for their structural,optical,and electrical properties.Later the nano-composite is deposited on the interdigitated electrode(IDE)pattern to form NO_(2)and CO_(2)sensors.The deposited films are then exposed to NO_(2)and CO_(2)gases separately and their response and recovery times are determined using a custom-built gas sensing setup.Nickel oxide-graphene provides a good response time and recovery time of 10 and 9 s,respectively for NO_(2),due to the higher electron affinity of graphene towards NO_(2).Nickel oxide-silver nanowire nano-composite is suited for CO_(2)gas because silver is an excellent electrocatalyst for CO_(2)by giving response and recovery times of 11 s each.This is the first report showcasing NiO nano-composites for NO_(2)and CO_(2)sensing at room temperature.展开更多
Layered transition metal oxides have emerged as promising cathode materials for sodium ion batteries.However,irreversible phase transitions cause structural distortion and cation rearrangement,leading to sluggish Na+d...Layered transition metal oxides have emerged as promising cathode materials for sodium ion batteries.However,irreversible phase transitions cause structural distortion and cation rearrangement,leading to sluggish Na+dynamics and rapid capacity decay.In this study,we propose a medium-entropy cathode by simultaneously introducing Fe,Mg,and Li dopants into a typical P2-type Na_(0.75)Ni_(0.25)Mn_(0.75)O_(2)cathode.The modified Na_(0.75)Ni_(0.2125)Mn_(0.6375)Fe_(0.05)Mg_(0.05)Li_(0.05)O_(2)cathode predominantly exhibits a main P2 phase(93.5%)with a minor O3 phase(6.5%).Through spectroscopy techniques and electrochemical investigations,we elucidate the redox mechanisms of Ni^(2+/3+/4+),Mn^(3+/4+),Fe^(3+/4+),and O_(2)-/O_(2)^(n-)during charging/discharging.The medium-entropy doping mitigates the detrimental P2-O_(2)phase transition at high-voltage,replacing it with a moderate and reversible structural evolution(P2-OP4),thereby enhancing structural stability.Consequently,the modified cathode exhibits a remarkable rate capacity of 108.4 mAh·g^(-1)at 10C,with a capacity retention of 99.0%after 200 cycles at 1C,82.5%after 500 cycles at 5C,and 76.7%after 600 cycles at 10C.Furthermore,it also demonstrates superior electrochemical performance at high cutoff voltage of 4.5 V and extreme temperature(55 and 0℃).This work offers solutions to critical challenges in sodium ion batteries cathode materials.展开更多
Against the backdrop of global energy and environmental crises,the technology of CO_(2)hydrogenation to produce methanol is garnering widespread attention as an innovative carbon capture and utilization solution.Bimet...Against the backdrop of global energy and environmental crises,the technology of CO_(2)hydrogenation to produce methanol is garnering widespread attention as an innovative carbon capture and utilization solution.Bimetallic oxide catalysts have emerged as the most promising research subject in the field due to their exceptional catalytic performance and stability.The performance of bimetallic oxide catalysts is influenced by multiple factors,including the selection of carrier materials,the addition of promoters,and the synthesis process.Different types of bimetallic oxide catalysts exhibit significant differences in microstructure,surface active sites,and electronic structure,which directly determine the yield and selectivity of methanol.Although bimetallic oxide catalysts offer significant advantages over traditional copper-based catalysts,they still encounter challenges related to activity and cost.In order to enhance catalyst performance,future investigations must delve into microstructure control,surface modification,and reaction kinetics.展开更多
The cobalt-free Mn-based Li-rich layered oxide material has the advantages of low cost,high energy density,and good performance at low temperatures,and is the promising choice for energy storage batteries.However,the ...The cobalt-free Mn-based Li-rich layered oxide material has the advantages of low cost,high energy density,and good performance at low temperatures,and is the promising choice for energy storage batteries.However,the long-cycling stability of batteries needs to be improved.Herein,the Mn-based Li-rich cathode materials with small amounts of Li2 MnO3 crystal domains and gradient doping of Al and Ti elements from the surface to the bulk have been developed to improve the structure and interface stability.Then the batteries with a high energy density of 600 Wh kg^(-1),excellent capacity retention of 99.7%with low voltage decay of 0.03 mV cycle^(-1) after 800 cycles,and good rates performances can be achieved.Therefore,the structure and cycling stability of low voltage Mn-based Li-rich cathode materials can be significantly improved by the bulk structure design and interface regulation,and this work has paved the way for developing low-cost and high-energy Mn-based energy storage batteries with long lifetime.展开更多
The global ocean is a major source of the climate-relevant atmospheric trace gas nitrous oxide(N_(2)O).However,an accurate assessment of the global oceanic emissions of N_(2)O is hampered by missing data on dissolved ...The global ocean is a major source of the climate-relevant atmospheric trace gas nitrous oxide(N_(2)O).However,an accurate assessment of the global oceanic emissions of N_(2)O is hampered by missing data on dissolved N_(2)O from large regions such as the Southern Ocean.To address this deficit,N_(2)O was measured in the Prydz Bay in February 2015 during the 31st Chinese National Antarctic Research Expedition.N_(2)O concentrations(saturation)in the surface layer were generally low(undersaturation with respect to atmospheric equilibrium)and ranged from 13.3 nmol/L to 16.1 nmol/L(83%–102%)at the time of sampling.A comparison of our observations with archived data revealed that no discernible trend in N_(2)O concentrations in the surface waters of Prydz Bay could be detected for the period between 2006 and 2015.Temperature and salinity changes driven by meltwater input were the predominant controls on N_(2)O concentrations in surface waters.At depth,the distribution of N_(2)O concentrations was dominated by production via nitrification in offshore deep waters and vertical convection in the shelf waters,where concentrations were lower and gradients were less steep.Our results suggest a rather unusual pattern of N_(2)O distribution in the Prydz Bay(low N_(2)O in shelf waters compared with the open ocean),providing important insights into the coastal dynamics of N_(2)O in high-latitude polar regions.展开更多
Reversible solid oxide cells(RSOCs)are capable of converting various energy resources,between electricity and chemical fuels,with high efficiency and flexibility,making them suitable for grid balancing and renewable e...Reversible solid oxide cells(RSOCs)are capable of converting various energy resources,between electricity and chemical fuels,with high efficiency and flexibility,making them suitable for grid balancing and renewable energy consumption.However,the practical application of RSOCs is still limited by the insufficient activity and stability of the electrodes in different operating modes.Herein,a highly efficient symmetrical electrode composed of La_(0.3)Sr_(0.6)Ti_(0.1)Co_(0.2)Fe_(0.7)O_(3-δ)(LSTCF)nanofibers and in situ exsolved Co_(3)Fe_(7) nanoparticles is developed for boosting the performance of RSOCs.The reversible phase transition,high activity and stability of the electrode have been confirmed by a combination of experimental(e.g.,transmission electron microscopy and X-ray absorption fine structure)and computational studies.Electrolyte-supported RSOCs with the symmetrical electrode demonstrate excellent catalytic activity and stability,achieving a high peak power density of 0.98 W cm^(-2)in the fuel cell mode using H_(2)as the fuel(or 0.53 W cm^(-2)using CH_(4)as the fuel)and a high current density of 1.09 A cm^(-2) at 1.4 V in the CO_(2)electrolysis mode(or 1.03 A cm^(-2)at 1.3 V for H_(2)O electrolysis)at 800℃while maintaining excellent durability for over 100 h.展开更多
The reaction characteristics of calcium-based materials during calcium looping(CaL)process are pivotal in the efficiency of CaL thermochemical energy storage(TCES)and CO_(2)capture systems.Currently,metal oxide doping...The reaction characteristics of calcium-based materials during calcium looping(CaL)process are pivotal in the efficiency of CaL thermochemical energy storage(TCES)and CO_(2)capture systems.Currently,metal oxide doping is the primary method to enhance the reaction characteristics of calcium-based materials over multiple cycles.In particular,co-doping with variable-valence metal oxides(VVMOs)can effectively increase the oxygen vacancy content in calcium-based materials,significantly improving their cyclic reaction characteristics.However,there are so numerous VVMOs co-doping schemes that the experimental screening process is complex,consuming considerable time and economic costs.Density functional theory(DFT)calculations have been widely used to reveal the impact of metal oxide doping on the cyclic reaction characteristics of calcium-based materials,with calculation results showing good agreement with experimental conclusions.Nevertheless,there is still a lack of research on utilizing DFT to screen calcium-based materials,and a systematic research methodology has not yet been established.In this study,a systematic DFT-based screening methodology for calcium-based materials was proposed.A series of key parameters for DFT calculations including CO_(2)adsorption energy,oxygen vacancy formation energy,and sintering resistance were proposed.Furthermore,a preliminary mathematical model to predict the CaL TCES and CO_(2)capture performance of calcium-based materials was introduced.The aforementioned DFT method was employed to screen for VVMOs co-doped calcium-based materials.The results revealed that Mn and Ce co-doped calcium-based materials exhibited superior DFT-predicted reaction characteristics.These DFT predictions were validated through experimental assessments of cyclic thermochemical energy storage,CO_(2)capture,and relevant characterization.The outcomes demonstrate a high degree of consistency among DFT-based predictions,experimental results,and characterization.Hence,the DFT-based screening methodology for calcium-based materials proposed herein is a viable solution,poised to offer theoretical insights for the efficient design of calcium-based materials.展开更多
Broadband transparent films play a pivotal role in various applications such as lenses and solar cells,particularly porous structured transparent films exhibit significant potential.This study investigates a porous Si...Broadband transparent films play a pivotal role in various applications such as lenses and solar cells,particularly porous structured transparent films exhibit significant potential.This study investigates a porous SiO_(2) refractive index gradient anti-reflective film prepared by atomic layer deposition(ALD).A porous SiO_(2) film with gradual porosity was obtained by phosphoric acid etching of Al_(2)O_(3)/SiO_(2) multilayers with gradient Al2O3 ratios,achieving a gradual decrease in refractive index from the substrate to the surface.The film exhibited an average transmittance as high as 97.8%within the wavelength range from 320 nm to 1200 nm.The environmental adaptability was further enhanced by surface modification using rare earth oxide(REO)La_(2)O_(3),resulting in formation of a lotus leaf-like structure and achieving a water contact angle of 100.0°.These data proved that the modification significantly improved hydrophobic self-cleaning capability while maintaining exceptional transparency of the film.The surface structure of the modified film remained undamaged even after undergoing wipe testing,demonstrating its excellent surface durability.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
Al-doped manganese dioxide(MnO_(2))was synthesized by simple hydrothermal method,and a controllable phase transition of the MnO_(2)crystal phase fromβtoδwas achieved.The effects of Al doping concentration on the str...Al-doped manganese dioxide(MnO_(2))was synthesized by simple hydrothermal method,and a controllable phase transition of the MnO_(2)crystal phase fromβtoδwas achieved.The effects of Al doping concentration on the structure and electrochemical properties of electrode materials were studied in detail.The results show that the controlled synthesis requires a synergy between KMnO_(4),MnCl_(2)and AlCl_(3),and that Al^(3+)plays an important role.Compared with the pure phase MnO_(2),the crystallinity of Al-doped MnO_(2)decreases and the specific surface area increases,which provides more active sites for the electrode material.When 3 mmol Al^(3+)is added,the prepared MnO_(2)-3 has the largest specific capacitance and the highest rate performance.The energy density of the asymmetric supercapacitor(ASC)with MnO_(2)-3 as the positive electrode and activated carbon(AC)as the negative electrode can reach 18.4 W·h/kg at the power density of 400 W/kg,and the capacity can maintain 90%of the initial value after 20000 cycles,indicating that Al-doped MnO_(2)has certain practical application value.This study provides favorable guidance for MnO_(2)as a high performance electrode material.展开更多
The rising level of CO_(2) concentration in the atmosphere poses major threats to the global climate and environment.Various technologies have been developed to mitigate its negative effects through nonconversion and ...The rising level of CO_(2) concentration in the atmosphere poses major threats to the global climate and environment.Various technologies have been developed to mitigate its negative effects through nonconversion and conversion routes.Particularly,solid oxide electrolysis cells(SOECs),as a promising technology with the highest energy efficiency,have garnered considerable attention for their effectiveness to electrochemically convert CO_(2) into high-value fuels.However,the insufficient catalytic activity,poor longterm stability,and high costs have significantly hindered the industrial-scale application of SOECs.To this end,substantial efforts,with an emphasis on the smart design of targeting electrode materials for specific applications have been devoted to advancing the electrosynthesis of high-value fuels from CO_(2) in various SOECs,but there still lacks a critical and comprehensive review in-depth discussing the fundamentals,and summarizing the latest advances in various applications and electrode materials for electrochemically converting CO_(2) to high-value fuels in SOECs.This review thus aims to fill this gap by focusing on the fundamentals(i.e.,SOEC working principles,thermodynamics,kinetics and representative evaluation parameters),specific applications(i.e.,pure CO_(2) electrolysis,CO_(2)-H_(2)O co-electrolysis,fuel-assisted CO_(2) conversion),and material selection criteria(i.e.,cathodic materials for CO_(2) conversion,and anodic materials for fuel-assisted CO_(2) conversion).In addition,the challenges that this technology is currently facing,and our perspectives on electrochemical CO_(2) conversion in SOECs are proposed to guide the smart design of high-performance electrocatalysts and future industrial-scale application of SOECs for electrosynthesizing high-value fuels from CO_(2).展开更多
Optical polarizers,which allow the transmission of specific polarization states,are essential components in modern optical systems.Here,we experimentally demonstrate integrated photonic polarizers incorporating reduce...Optical polarizers,which allow the transmission of specific polarization states,are essential components in modern optical systems.Here,we experimentally demonstrate integrated photonic polarizers incorporating reduced graphene oxide(rGO)films.2D graphene oxide(GO)films are integrated onto silicon waveguides and microring resonators(MRRs)with precise control over their thicknesses and sizes,followed by GO reduction via two different methods including uniform thermal reduction and localized photothermal reduction.We measure devices with various lengths,thicknesses,and reduction degrees of GO films.The results show that the devices with rGO exhibit better performance than those with GO,achieving a polarization-dependent loss of~47 dB and a polarization extinction ratio of~16 dB for the hybrid waveguides and MRRs with rGO,respectively.By fitting the experimental results with theory,it is found that rGO exhibits more significant anisotropy in loss,with an anisotropy ratio over 4 times that of GO.In addition,rGO shows higher thermal stability and greater robustness to photothermal reduction than GO.These results highlight the strong potential of rGO films for implementing high-performance polarization selective devices in integrated photonic platforms.展开更多
Ta-doped SnO_(2)(TTO)is a suitable candidate to replace transparent conductive oxide(TCO)composed of expensive indium used for optoelectronics and silicon heterojunction solar cells fabricated below 200℃.However,TTO ...Ta-doped SnO_(2)(TTO)is a suitable candidate to replace transparent conductive oxide(TCO)composed of expensive indium used for optoelectronics and silicon heterojunction solar cells fabricated below 200℃.However,TTO films fabricated by sputtering at low temperature still demonstrate too high resistance and optical absorptance for application in industry.In this study,we investigate the influence of sputtering ambient on the optoelectrical properties of TTO films.The addition of hydrogen and oxygen to argon during sputtering leads to a large improvement in the optoelectrical properties of TTO films.The best TTO film has a low average absorptance of 1.9%and a low resistance of 3.8×10^(-3)Ω·cm with a high carrier density of 9.3×10^(19)cm^(-3)and mobility of 17.8 cm^(2)·V^(-1)·s^(-1).The micros tructural and compositional properties of TTO films were characterized using x-ray diffraction,x-ray photoelectron spectroscopy and UV-Vis spectrophotometry.A proper ratio of hydrogen to oxygen in the sputtering gas improves the crystallinity and the doping efficiency of Ta.Optical absorptance is also reduced with suppressed formation of Sn(Ⅱ)in the TTO films.Therefore,our findings exhibit remarkable potential for the industrial application of TTO as a low-cost TCO.展开更多
Two-dimensional(2D)metal oxides(2DMOs),such as MoO_(2),have made impressive strides in recent years,and their applicability in a number of fields such as electronic devices,optoelectronic devices and lasers has been d...Two-dimensional(2D)metal oxides(2DMOs),such as MoO_(2),have made impressive strides in recent years,and their applicability in a number of fields such as electronic devices,optoelectronic devices and lasers has been demonstrated.However,2DMOs present challenges in their synthesis using conventional methods due to their non-van der Waals nature.We report that KCl acts as a flux to prepare large-area 2DMOs with sub-millimeter scale.We systematically investigate the effects of temperature,homogeneous time and cooling rate on the products in the flux method,demonstrating that in this reaction a saturated homogenous solution is obtained upon the melting of the salt and precursor.Afterward,the cooling rate was adjusted to regulate the thickness of the target crystals,leading to the precipitation of 2D non-layered material from the supersaturated solution;by applying this method,the highly crystalline non-layered 2D MoO_(2)flakes with so far the largest lateral size of up to sub-millimeter scale(~464μm)were yielded.Electrical studies have revealed that the 2D MoO_(2)features metallic properties,with an excellent sheet resistance as low as 99Ω·square^(-1 )at room temperature,and exhibits a property of charge density wave in the measurement of resistivity as a function of temperature.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.22476187 and 22206173)the Natural Science Foundation of Henan Province(Grant No.252300421179)+1 种基金the Foundation of Henan Educational Committee(Grant No.25A610001)the Science and Technology Innovation Leading Talent Support Program of Henan Province(Grant No.254000510035).
文摘Fenton technology has garnered significant attention for the deep removal of low-concentration emerging contaminants due to its remarkable oxidation performance.However,the traditional mineralization process for emerging contaminants requires a substantial amount of hydroxyl radicals(HO˙),leading to excessive consumption of H_(2)O_(2).Through interfacial engineering of Fe-Zr bimetallic catalysts(FeZrO_(x)),this study demonstrates synergistic enhancement of phenolic pollutant removal at heterojunction interfaces while achieving an 80%reduction in H_(2)O_(2)dosage compared to traditional Fe_(2)O_(3)systems.The chemical states of Fe and Zr at the(104)/(111)heterojunction interface in FeZrO_(x)exhibit marked modifications relative to their monometallic Fe_(2)O_(3)and ZrO_(2)counterparts.The elevated charge density at interfacial Fe sites in FeZrO_(x)promotes HO˙generation,while optimized antibonding orbital composition below the Fermi level in bisphenol A adsorbed on Zr sites enhances hydrogen abstraction and subsequent polymerization.This Fe-Zr synergy at the(104)/(111)heterojunction concurrently suppresses HO˙diffusion losses and directs phenolic pollutant(e.g.,phenol and bisphenol A)polymerization within the reactive interface,thereby reducing H_(2)O_(2)consumption compared to monometallic systems.
基金supported by the National Natural Science Foundation of China(52374311)National Key R&D Program of China(2023YFE0203000)+3 种基金the National Natural Science Foundation of Shaanxi(2023KXJ-262,2025SYS-SYSZD-035)the Fund of the State Key Laboratory of Solidification Processing in NPU(2025-TS-10)the Fundamental Research Funds for the Central Universities(D5000250277)the Youth Innovation Team of Shaanxi Universities。
文摘Layered oxides present compelling potential as cathode materials for sodium-ion batteries(SIBs).However,challenges including interfacial instability and sluggish reaction kinetics critically limit their rate capability and cycling performance.Herein,we introduce the water-soluble sodium polyacrylate(NaPAA)binder as a promising approach to mitigating these issues in P2-type layered oxides.The NaPAA binder facilitates the formation of a uniform Na^(+) conductive interfacial film,which protects the cathode against electrolyte-induced corrosion and effectively inhibits the dissolution of transition metals in P2-Na_(0.85)Li_(0.12)Ni_(0.22)Mn_(0.66)O_(2)(NLNMO).Furthermore,we elucidate the mechanism by which the NaPAA binder dynamically regulates the coordination of free anions at the electrode-electrolyte interface.This regulation reduces solvent decomposition and promotes the formation of a stable,ionically conductive layer.Consequently,the P2-NLNMO@NaPAA integrated electrode exhibits enhanced electrochemical performance,achieving an 89.2%capacity retention after 200 cycles at 0.2 C and delivering an initial capacity of 102.9 mA h g^(-1) even at 0℃.This study advances the fundamental understanding of binder-mediated interface engineering and demonstrates a scalable and eco-friendly manufacturing pathway for high-performance SIBs.
基金the National Natural Science Foundation of China(22002008,22202226,22468042)Ningxia Key Research and Development Project(2022BEE03002,2022 BSB03056)+1 种基金the Fourth Batch of Ningxia Youth Talents Supporting Program(TJGC2019022)West Light Foundation of the Chinese Academy of Sciences(XAB2019AW02).
文摘The conversion of CO_(2) into high value added chemicals via the Fischer-Tropsch synthesis(FTS)reaction has attracted significant attention.The surface oxygenation environment is a significant factor influencing the performance of the catalyst.In this work,spin-polarized density-functional theory calculations have been used to investigate the adsorption and reactions of CO_(2) and H to generate CH4 and CH3OH on Fe_(5)C_(2)(100)surfaces with varying OH∗coverage.On the pure Fe_(5)C_(2)(100)surface,surface C^(∗) preferentially reacts with hydrogen to form CH4,exposing C^(∗) vacancy.CO_(2) favors adsorbing on the C^(∗) vacancy to further dissociating and activating.The co-adsorption of OH∗promotes the C^(∗) cycle process by facilitating the hydrogenation of C^(∗).The Fe_(5)C_(2) surface with an oxide interface is favorable for reducing FexOy,thereby maintaining the dynamic stability of the surface.Therefore,surface oxidation is inevitably involved in the entire C^(∗) cycle of the FTS reaction and regulates the relative content of iron oxides and iron carbides.Our work can contribute to the rational modulation of the surface C^(∗) cycle,thereby enhancing catalyst performance.
基金supported by the National Natural Science Foundation of China (No. 52374292)China Baowu Low Carbon Metallurgy Innovation Foundation, China (No. BWLCF202309)the Natural Science Foundation of Changsha City, China (No. KQ2208271)。
文摘Some active metal oxides(Al_(2)O_(3),TiO_(2),and Cr_(2)O_(3))were selected as dopants to the Al_(2)O_(3)-based ceramic shells for investment casting of K417G superalloy.The effects of dopant types and contents(0,2,5,and 8 wt.%)on the wettability and interfacial reaction between the alloy and shell were investigated by a sessile-drop experiment.The results show that increasing the Al_(2)O_(3) doping contents(0−8 wt.%)reduces the porosity(21.74%−10.08%)and roughness(3.22−1.34μm)of the shell surface.The increase in Cr_(2)O_(3) dopant content(2−8 wt.%)further exacerbates the interfacial reaction,leading to an increase in the thickness of the reaction layer(2.6−3.1μm)and a decrease in the wetting angle(93.9°−91.0°).The addition of Al_(2)O_(3) and TiO_(2) dopants leads to the formation of Al_(2)TiO_(5) composite oxides in the reaction products,which effectively inhibits the interfacial reaction.The increase in TiO_(2) dopant contents(0−8 wt.%)further promotes the formation of Al_(2)TiO_(5),which decreases the thickness of the interfacial reaction layer(3.9−1.2μm)and increases the wetting angle(95.0°−103.8°).The introduced dopants enhance the packing density of the shell surface,while simultaneously suppress the diffusion of active metal elements from the alloy matrix to the interface.
基金financially supported by the National Natural Science Foundation of China (No. 21273080)Guangdong Natural Science Foundation (No. 2014A030311039)
文摘In this study, a new facile preparation method of nanocomposites consisting of graphene oxide and manganese dioxide nanowires（GO/MnO2 NWs） was developed. The morphology, structure and composition of the resulted products were characterized by transmission electron microscopy, X-ray diffraction and N2 adsorption and desorption. The GO/MnO2 nanocomposite was used as an electrode material for non-enzymatic determination of hydrogen peroxide. The proposed sensor exhibits excellent electrocatalytic performance for the determination of hydrogen peroxide in phosphate buffer solution（PBS, pH7） at an applied potential of 0.75 V. The non-enzymatic biosensor for determination of hydrogen peroxide displayed a wide linear range of 4.90 mmol L^-1–4.50 mmol L^-1with a correlation coefficient of 0.9992, a low detection limit of 0.48 mmol L^-1 and a high sensitivity of 191.22μA（mmol L^-1）^-1cm^-2（signal/noise, S/N = 3）. Moreover, the non-enzymatic biosensor shows an excellent selectivity.
基金financially National Key R&D Program of China(No.2022YFA1504800)National Natural Science Foundation of China(Grant No.22325405,22372160,22321002)+1 种基金Liaoning Revitalization Talents Program(XLYC1807207)DICP I202104。
文摘The Zn-Al spinel oxide stands out as one of the most active catalysts for high-temperature methanol synthesis from CO_(2)hydrogenation.However,the structure–activity relationship of the reaction remains poorly understood due to challenges in atomic-level structural characterizations and analysis of reaction intermediates.In this study,we prepared two Zn-Al spinel oxide catalysts via coprecipitation(ZnAl-C)and hydrothermal(ZnAl-H)methods,and conducted a comparative investigation in the CO_(2)hydrogenation reaction.Surprisingly,under similar conditions,ZnAl-C exhibited significantly higher selectivity towards methanol and DME compared to ZnAl-H.Comprehensive characterizations using X-ray diffraction(XRD),Raman spectroscopy and electron paramagnetic resonance(EPR)unveiled that ZnAl-C catalyst had abundant ZnO species on its surface,and the interaction between the ZnO species and its ZnAl spinel oxide matrix led to the formation of oxygen vacancies,which are crucial for CO_(2)adsorption and activation.Additionally,state-of-the-art solid-state nuclear magnetic resonance(NMR)techniques,including ex-situ and in-situ NMR analyses,confirmed that the surface ZnO facilitates the formation of unique highly reactive interfacial formate species,which was readily hydrogenated to methanol and DME.These insights elucidate the promotion effects of ZnO on the ZnAl spinel oxide in regulating active sites and reactive intermediates for CO_(2)-to-methanol hydrogenation reaction,which is further evidenced by the significant enhancement in methanol and DME selectivity observed upon loading ZnO onto the ZnAl-H catalyst.These molecular-level mechanism understandings reinforce the idea of optimizing the ZnO-ZnAl interface through tailored synthesis methods to achieve activity-selectivity balance.
文摘The rapid industrial growth and increasing population have led to significant pollution and deterioration of the natural atmospheric environment.Major atmospheric pollutants include NO_(2)and CO_(2).Hence,it is imperative to develop NO_(2)and CO_(2)sensors for ambient conditions,that can be used in indoor air quality monitoring,breath analysis,food spoilage detection,etc.In the present study,two thin film nanocomposite(nickel oxide-graphene and nickel oxide-silver nanowires)gas sensors are fabricated using direct ink writing.The nano-composites are investigated for their structural,optical,and electrical properties.Later the nano-composite is deposited on the interdigitated electrode(IDE)pattern to form NO_(2)and CO_(2)sensors.The deposited films are then exposed to NO_(2)and CO_(2)gases separately and their response and recovery times are determined using a custom-built gas sensing setup.Nickel oxide-graphene provides a good response time and recovery time of 10 and 9 s,respectively for NO_(2),due to the higher electron affinity of graphene towards NO_(2).Nickel oxide-silver nanowire nano-composite is suited for CO_(2)gas because silver is an excellent electrocatalyst for CO_(2)by giving response and recovery times of 11 s each.This is the first report showcasing NiO nano-composites for NO_(2)and CO_(2)sensing at room temperature.
基金supported by the National Natural Science Foundation of China(No.21805018)by Sichuan Science and Technology Program(Nos.2022ZHCG0018,2023NSFSC0117 and 2023ZHCG0060)Yibin Science and Technology Program(No.2022JB005)and China Postdoctoral Science Foundation(No.2022M722704).
文摘Layered transition metal oxides have emerged as promising cathode materials for sodium ion batteries.However,irreversible phase transitions cause structural distortion and cation rearrangement,leading to sluggish Na+dynamics and rapid capacity decay.In this study,we propose a medium-entropy cathode by simultaneously introducing Fe,Mg,and Li dopants into a typical P2-type Na_(0.75)Ni_(0.25)Mn_(0.75)O_(2)cathode.The modified Na_(0.75)Ni_(0.2125)Mn_(0.6375)Fe_(0.05)Mg_(0.05)Li_(0.05)O_(2)cathode predominantly exhibits a main P2 phase(93.5%)with a minor O3 phase(6.5%).Through spectroscopy techniques and electrochemical investigations,we elucidate the redox mechanisms of Ni^(2+/3+/4+),Mn^(3+/4+),Fe^(3+/4+),and O_(2)-/O_(2)^(n-)during charging/discharging.The medium-entropy doping mitigates the detrimental P2-O_(2)phase transition at high-voltage,replacing it with a moderate and reversible structural evolution(P2-OP4),thereby enhancing structural stability.Consequently,the modified cathode exhibits a remarkable rate capacity of 108.4 mAh·g^(-1)at 10C,with a capacity retention of 99.0%after 200 cycles at 1C,82.5%after 500 cycles at 5C,and 76.7%after 600 cycles at 10C.Furthermore,it also demonstrates superior electrochemical performance at high cutoff voltage of 4.5 V and extreme temperature(55 and 0℃).This work offers solutions to critical challenges in sodium ion batteries cathode materials.
文摘Against the backdrop of global energy and environmental crises,the technology of CO_(2)hydrogenation to produce methanol is garnering widespread attention as an innovative carbon capture and utilization solution.Bimetallic oxide catalysts have emerged as the most promising research subject in the field due to their exceptional catalytic performance and stability.The performance of bimetallic oxide catalysts is influenced by multiple factors,including the selection of carrier materials,the addition of promoters,and the synthesis process.Different types of bimetallic oxide catalysts exhibit significant differences in microstructure,surface active sites,and electronic structure,which directly determine the yield and selectivity of methanol.Although bimetallic oxide catalysts offer significant advantages over traditional copper-based catalysts,they still encounter challenges related to activity and cost.In order to enhance catalyst performance,future investigations must delve into microstructure control,surface modification,and reaction kinetics.
基金supported by the National Key R&D Program of China(No.2022YFB2404400)the National Natural Science Foundation of China(Nos.U23A20577,52372168,92263206 and 21975006)+1 种基金the“The Youth Beijing Scholars program”(No.PXM2021_014204_000023)the Beijing Natural Science Foundation(Nos.2222001 and KM202110005009).
文摘The cobalt-free Mn-based Li-rich layered oxide material has the advantages of low cost,high energy density,and good performance at low temperatures,and is the promising choice for energy storage batteries.However,the long-cycling stability of batteries needs to be improved.Herein,the Mn-based Li-rich cathode materials with small amounts of Li2 MnO3 crystal domains and gradient doping of Al and Ti elements from the surface to the bulk have been developed to improve the structure and interface stability.Then the batteries with a high energy density of 600 Wh kg^(-1),excellent capacity retention of 99.7%with low voltage decay of 0.03 mV cycle^(-1) after 800 cycles,and good rates performances can be achieved.Therefore,the structure and cycling stability of low voltage Mn-based Li-rich cathode materials can be significantly improved by the bulk structure design and interface regulation,and this work has paved the way for developing low-cost and high-energy Mn-based energy storage batteries with long lifetime.
基金The National Natural Science Foundation of China under contract No.41906193the Scientific Research Foundation of Third Institute of Oceanography,Ministry of Natural Resources,under contract No.2019033+2 种基金the Natural Science Foundation of Fujian Province under contract No.2019J05147the Federal Ministry of Education and Research of Germany under contract No.FKZ 03F03F0783Athe National Polar Special Program under contract Nos IRASCC 01-01-02 and IRASCC 02-02.
文摘The global ocean is a major source of the climate-relevant atmospheric trace gas nitrous oxide(N_(2)O).However,an accurate assessment of the global oceanic emissions of N_(2)O is hampered by missing data on dissolved N_(2)O from large regions such as the Southern Ocean.To address this deficit,N_(2)O was measured in the Prydz Bay in February 2015 during the 31st Chinese National Antarctic Research Expedition.N_(2)O concentrations(saturation)in the surface layer were generally low(undersaturation with respect to atmospheric equilibrium)and ranged from 13.3 nmol/L to 16.1 nmol/L(83%–102%)at the time of sampling.A comparison of our observations with archived data revealed that no discernible trend in N_(2)O concentrations in the surface waters of Prydz Bay could be detected for the period between 2006 and 2015.Temperature and salinity changes driven by meltwater input were the predominant controls on N_(2)O concentrations in surface waters.At depth,the distribution of N_(2)O concentrations was dominated by production via nitrification in offshore deep waters and vertical convection in the shelf waters,where concentrations were lower and gradients were less steep.Our results suggest a rather unusual pattern of N_(2)O distribution in the Prydz Bay(low N_(2)O in shelf waters compared with the open ocean),providing important insights into the coastal dynamics of N_(2)O in high-latitude polar regions.
基金supported by the National Natural Science Foundation of China(No.52377212 and 51877173)program of Beijing Huairou Laboratory(ZD2022006A)+2 种基金the Key R&D Project of Shaanxi Province(2023-YBGY-057)the State Key Laboratory of Electrical Insulation and Power Equipment(EIPE22314,EIPE22306)the Natural Science Basic Research Program of Shaanxi(No.2023-JC-QN-0483).
文摘Reversible solid oxide cells(RSOCs)are capable of converting various energy resources,between electricity and chemical fuels,with high efficiency and flexibility,making them suitable for grid balancing and renewable energy consumption.However,the practical application of RSOCs is still limited by the insufficient activity and stability of the electrodes in different operating modes.Herein,a highly efficient symmetrical electrode composed of La_(0.3)Sr_(0.6)Ti_(0.1)Co_(0.2)Fe_(0.7)O_(3-δ)(LSTCF)nanofibers and in situ exsolved Co_(3)Fe_(7) nanoparticles is developed for boosting the performance of RSOCs.The reversible phase transition,high activity and stability of the electrode have been confirmed by a combination of experimental(e.g.,transmission electron microscopy and X-ray absorption fine structure)and computational studies.Electrolyte-supported RSOCs with the symmetrical electrode demonstrate excellent catalytic activity and stability,achieving a high peak power density of 0.98 W cm^(-2)in the fuel cell mode using H_(2)as the fuel(or 0.53 W cm^(-2)using CH_(4)as the fuel)and a high current density of 1.09 A cm^(-2) at 1.4 V in the CO_(2)electrolysis mode(or 1.03 A cm^(-2)at 1.3 V for H_(2)O electrolysis)at 800℃while maintaining excellent durability for over 100 h.
基金supported by the National Natural Science Foundation of China(52276204 and U22A20435)。
文摘The reaction characteristics of calcium-based materials during calcium looping(CaL)process are pivotal in the efficiency of CaL thermochemical energy storage(TCES)and CO_(2)capture systems.Currently,metal oxide doping is the primary method to enhance the reaction characteristics of calcium-based materials over multiple cycles.In particular,co-doping with variable-valence metal oxides(VVMOs)can effectively increase the oxygen vacancy content in calcium-based materials,significantly improving their cyclic reaction characteristics.However,there are so numerous VVMOs co-doping schemes that the experimental screening process is complex,consuming considerable time and economic costs.Density functional theory(DFT)calculations have been widely used to reveal the impact of metal oxide doping on the cyclic reaction characteristics of calcium-based materials,with calculation results showing good agreement with experimental conclusions.Nevertheless,there is still a lack of research on utilizing DFT to screen calcium-based materials,and a systematic research methodology has not yet been established.In this study,a systematic DFT-based screening methodology for calcium-based materials was proposed.A series of key parameters for DFT calculations including CO_(2)adsorption energy,oxygen vacancy formation energy,and sintering resistance were proposed.Furthermore,a preliminary mathematical model to predict the CaL TCES and CO_(2)capture performance of calcium-based materials was introduced.The aforementioned DFT method was employed to screen for VVMOs co-doped calcium-based materials.The results revealed that Mn and Ce co-doped calcium-based materials exhibited superior DFT-predicted reaction characteristics.These DFT predictions were validated through experimental assessments of cyclic thermochemical energy storage,CO_(2)capture,and relevant characterization.The outcomes demonstrate a high degree of consistency among DFT-based predictions,experimental results,and characterization.Hence,the DFT-based screening methodology for calcium-based materials proposed herein is a viable solution,poised to offer theoretical insights for the efficient design of calcium-based materials.
文摘Broadband transparent films play a pivotal role in various applications such as lenses and solar cells,particularly porous structured transparent films exhibit significant potential.This study investigates a porous SiO_(2) refractive index gradient anti-reflective film prepared by atomic layer deposition(ALD).A porous SiO_(2) film with gradual porosity was obtained by phosphoric acid etching of Al_(2)O_(3)/SiO_(2) multilayers with gradient Al2O3 ratios,achieving a gradual decrease in refractive index from the substrate to the surface.The film exhibited an average transmittance as high as 97.8%within the wavelength range from 320 nm to 1200 nm.The environmental adaptability was further enhanced by surface modification using rare earth oxide(REO)La_(2)O_(3),resulting in formation of a lotus leaf-like structure and achieving a water contact angle of 100.0°.These data proved that the modification significantly improved hydrophobic self-cleaning capability while maintaining exceptional transparency of the film.The surface structure of the modified film remained undamaged even after undergoing wipe testing,demonstrating its excellent surface durability.
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Project(202203021221138)supported by the Collaborative Innovation Center for Shanxi Advanced Permanent Materials and Technologythe 1331 Engineering of Shanxi ProvinceFundamental Research Program of Shanxi Province,China。
文摘Al-doped manganese dioxide(MnO_(2))was synthesized by simple hydrothermal method,and a controllable phase transition of the MnO_(2)crystal phase fromβtoδwas achieved.The effects of Al doping concentration on the structure and electrochemical properties of electrode materials were studied in detail.The results show that the controlled synthesis requires a synergy between KMnO_(4),MnCl_(2)and AlCl_(3),and that Al^(3+)plays an important role.Compared with the pure phase MnO_(2),the crystallinity of Al-doped MnO_(2)decreases and the specific surface area increases,which provides more active sites for the electrode material.When 3 mmol Al^(3+)is added,the prepared MnO_(2)-3 has the largest specific capacitance and the highest rate performance.The energy density of the asymmetric supercapacitor(ASC)with MnO_(2)-3 as the positive electrode and activated carbon(AC)as the negative electrode can reach 18.4 W·h/kg at the power density of 400 W/kg,and the capacity can maintain 90%of the initial value after 20000 cycles,indicating that Al-doped MnO_(2)has certain practical application value.This study provides favorable guidance for MnO_(2)as a high performance electrode material.
基金supported by the Pilot Group Program of the Research Fund for International Senior Scientists(No.22350710789)the National Natural Science Foundation of China(NSFC,No.22109182)+2 种基金the Natural Science Foundation of Hunan Province,China(No.2022JJ30684)the Start-up Funding of Central South University(No.206030104)supported in part by the High-Performance Computing Center of Central South University。
文摘The rising level of CO_(2) concentration in the atmosphere poses major threats to the global climate and environment.Various technologies have been developed to mitigate its negative effects through nonconversion and conversion routes.Particularly,solid oxide electrolysis cells(SOECs),as a promising technology with the highest energy efficiency,have garnered considerable attention for their effectiveness to electrochemically convert CO_(2) into high-value fuels.However,the insufficient catalytic activity,poor longterm stability,and high costs have significantly hindered the industrial-scale application of SOECs.To this end,substantial efforts,with an emphasis on the smart design of targeting electrode materials for specific applications have been devoted to advancing the electrosynthesis of high-value fuels from CO_(2) in various SOECs,but there still lacks a critical and comprehensive review in-depth discussing the fundamentals,and summarizing the latest advances in various applications and electrode materials for electrochemically converting CO_(2) to high-value fuels in SOECs.This review thus aims to fill this gap by focusing on the fundamentals(i.e.,SOEC working principles,thermodynamics,kinetics and representative evaluation parameters),specific applications(i.e.,pure CO_(2) electrolysis,CO_(2)-H_(2)O co-electrolysis,fuel-assisted CO_(2) conversion),and material selection criteria(i.e.,cathodic materials for CO_(2) conversion,and anodic materials for fuel-assisted CO_(2) conversion).In addition,the challenges that this technology is currently facing,and our perspectives on electrochemical CO_(2) conversion in SOECs are proposed to guide the smart design of high-performance electrocatalysts and future industrial-scale application of SOECs for electrosynthesizing high-value fuels from CO_(2).
基金supported by the Australian Research Council Centre of Excellence Project in Optical Microcombs for Breakthrough Science(No.CE230100006)the Australian Research Council Discovery Projects Programs(Nos.P190103186 and FT210100806)+4 种基金Linkage Program(Nos.LP210200345 and LP210100467)the Swinburne ECR-SUPRA program,the Industrial Transformation Training Centres scheme(No.IC180100005)the National Natural Science Foundation of China(No.12404375)the Beijing Natural Science Foundation(No.Z180007)the Innovation Program for Quantum Science and Technology(No.2021ZD0300703).
文摘Optical polarizers,which allow the transmission of specific polarization states,are essential components in modern optical systems.Here,we experimentally demonstrate integrated photonic polarizers incorporating reduced graphene oxide(rGO)films.2D graphene oxide(GO)films are integrated onto silicon waveguides and microring resonators(MRRs)with precise control over their thicknesses and sizes,followed by GO reduction via two different methods including uniform thermal reduction and localized photothermal reduction.We measure devices with various lengths,thicknesses,and reduction degrees of GO films.The results show that the devices with rGO exhibit better performance than those with GO,achieving a polarization-dependent loss of~47 dB and a polarization extinction ratio of~16 dB for the hybrid waveguides and MRRs with rGO,respectively.By fitting the experimental results with theory,it is found that rGO exhibits more significant anisotropy in loss,with an anisotropy ratio over 4 times that of GO.In addition,rGO shows higher thermal stability and greater robustness to photothermal reduction than GO.These results highlight the strong potential of rGO films for implementing high-performance polarization selective devices in integrated photonic platforms.
基金Project supported by the Key-Area Research and Development Program of Guangdong Province,China(Grant No.2021B0101260001)the Guangdong Basic and Applied Basic Research Foundation(Grant No.2019A1515110411)。
文摘Ta-doped SnO_(2)(TTO)is a suitable candidate to replace transparent conductive oxide(TCO)composed of expensive indium used for optoelectronics and silicon heterojunction solar cells fabricated below 200℃.However,TTO films fabricated by sputtering at low temperature still demonstrate too high resistance and optical absorptance for application in industry.In this study,we investigate the influence of sputtering ambient on the optoelectrical properties of TTO films.The addition of hydrogen and oxygen to argon during sputtering leads to a large improvement in the optoelectrical properties of TTO films.The best TTO film has a low average absorptance of 1.9%and a low resistance of 3.8×10^(-3)Ω·cm with a high carrier density of 9.3×10^(19)cm^(-3)and mobility of 17.8 cm^(2)·V^(-1)·s^(-1).The micros tructural and compositional properties of TTO films were characterized using x-ray diffraction,x-ray photoelectron spectroscopy and UV-Vis spectrophotometry.A proper ratio of hydrogen to oxygen in the sputtering gas improves the crystallinity and the doping efficiency of Ta.Optical absorptance is also reduced with suppressed formation of Sn(Ⅱ)in the TTO films.Therefore,our findings exhibit remarkable potential for the industrial application of TTO as a low-cost TCO.
基金supported by the National Key Research and Development Program of China(Nos.2023YFB3608703 and 2023YFB3608700)Fujian Science&Technology Innovation Laboratory for Optoelectronic Information of China(Nos.2021ZZ122 and 2020ZZ110)Fujian provincial projects(Nos.2021HZ0114 and 2021J01583).
文摘Two-dimensional(2D)metal oxides(2DMOs),such as MoO_(2),have made impressive strides in recent years,and their applicability in a number of fields such as electronic devices,optoelectronic devices and lasers has been demonstrated.However,2DMOs present challenges in their synthesis using conventional methods due to their non-van der Waals nature.We report that KCl acts as a flux to prepare large-area 2DMOs with sub-millimeter scale.We systematically investigate the effects of temperature,homogeneous time and cooling rate on the products in the flux method,demonstrating that in this reaction a saturated homogenous solution is obtained upon the melting of the salt and precursor.Afterward,the cooling rate was adjusted to regulate the thickness of the target crystals,leading to the precipitation of 2D non-layered material from the supersaturated solution;by applying this method,the highly crystalline non-layered 2D MoO_(2)flakes with so far the largest lateral size of up to sub-millimeter scale(~464μm)were yielded.Electrical studies have revealed that the 2D MoO_(2)features metallic properties,with an excellent sheet resistance as low as 99Ω·square^(-1 )at room temperature,and exhibits a property of charge density wave in the measurement of resistivity as a function of temperature.
