Three-dimensional(3D)vertical architecture transistors represent an important technological pursuit,which have distinct advantages in device integration density,operation speed,and power consumption.However,the fabric...Three-dimensional(3D)vertical architecture transistors represent an important technological pursuit,which have distinct advantages in device integration density,operation speed,and power consumption.However,the fabrication processes of such 3D devices are complex,especially in the interconnection of electrodes.In this paper,we present a novel method which combines suspended electrodes and focused ion beam(FIB)technology to greatly simplify the electrodes interconnection in 3D devices.Based on this method,we fabricate 3D vertical core-double shell structure transistors with ZnO channel and Al_(2)O_(3) gate-oxide both grown by atomic layer deposition.Suspended top electrodes of vertical architecture could be directly connected to planar electrodes by FIB deposited Pt nanowires,which avoid cumbersome steps in the traditional 3D structure fabrication technology.Both single pillar and arrays devices show well behaved transfer characteristics with an Ion/Ioff current ratio greater than 106 and a low threshold voltage around 0 V.The ON-current of the 2×2 pillars vertical channel transistor was 1.2μA at the gate voltage of 3 V and drain voltage of 2 V,which can be also improved by increasing the number of pillars.Our method for fabricating vertical architecture transistors can be promising for device applications with high integration density and low power consumption.展开更多
Degradation of o-chloronitrobenzene wastewater was experimentally investigated at a three-dimensional electrode(TDE) with granular activated carbon as the particle electrode, graphite as the anode, and stainless ste...Degradation of o-chloronitrobenzene wastewater was experimentally investigated at a three-dimensional electrode(TDE) with granular activated carbon as the particle electrode, graphite as the anode, and stainless steel plate as the cathode. The kinetic model of o-chloronitrobenzene degradation was studied, and the effects of pH, electrolysis time, particle electrode, electrolyte concentration, and initial concentration of the solution on degradation efficiency were investigated to determine the optimal operating conditions. The degradation of o-chloronitrobenzene by oxidation at the TDE was monitored by chemical oxygen demand(COD) measurements, UV-Vis absorption, and high performance liquid chromatography(HPLC). COD degradation by electrochemical degradation followed pseudo-first order kinetics with respect to the concentration of o-chloronitrobenzene solutions. Optimal reaction conditions included 15 g of activated carbon as the particle electrode, 400 mg/L o-chloronitrobenzene solution containing 0.10 mol/L Na2SO4, pH=3, and 60 min of electrolysis. The UV-Vis absorption spectra and HPLC results illustrate that the benzene ring in o-chloronitrobenzene was rapidly broken down to form aliphatic substances through electrochemical degradation. COD degradation was approximately 98.5% at optimal conditions.展开更多
Electrochemical N_(2) reduction reaction(eNRR) over Cu-based catalysts suffers from an intrinsically low activity of Cu for activation of stable N_(2) molecules and the limited supply of N_(2) to the catalyst due to i...Electrochemical N_(2) reduction reaction(eNRR) over Cu-based catalysts suffers from an intrinsically low activity of Cu for activation of stable N_(2) molecules and the limited supply of N_(2) to the catalyst due to its low solubility in aqueous electrolytes.Herein,we propose phosphorus-activated Cu electrocatalysts to generate electron-deficient Cu sites on the catalyst surface to promote the adsorption of N_(2) molecules.The eNRR system is further modified using a gas diffusion electrode(GDE) coated with polytetrafluoroethylene(PTFE) to form an effective three-phase boundary of liquid water-gas N_(2)-solid catalyst to facilitate easy access of N_(2) to the catalytic sites.As a result,the new catalyst in the flow-type cell records a Faradaic efficiency of 13.15% and an NH_(3) production rate of 7.69 μg h^(-1) cm^(-2) at-0.2 V_(RHE),which represent 3.56 and 59.2 times increases from those obtained with a pristine Cu electrode in a typical electrolytic cell.This work represents a successful demonstration of dual modification strategies;catalyst modification and N_(2) supplying system engineering,and the results would provide a useful platform for further developments of electrocatalysts and reaction systems.展开更多
A method using three-dimensional electrode is applied to treat wastewater in oil fields, which contains polyacrylamide (PAM), for analogue. A best condition for electrolysis (I= 1.0 A, t=90 min, c=0.1%, m=980 g,φ=...A method using three-dimensional electrode is applied to treat wastewater in oil fields, which contains polyacrylamide (PAM), for analogue. A best condition for electrolysis (I= 1.0 A, t=90 min, c=0.1%, m=980 g,φ=5 mm, d=5.0 cm) has been determined, under which the COD removal efficiency reached 96.0%, COD containing in wastewater reduced to 64.3 mg/L from 1 622.9 mg/L, the figure before treatment. Three categories of PAM-containing wastewater in production practice have been treated with the COD removal ratios being 87.5%, 82.4% and 84.7% respectively. Presence of H2O2 and ·OH are detected by means of Ti(IV)-5-Br-PADAP technique and colorimetry respectively. The concentration is positively proportional to the COD removal ratio and increases in accordance with increment of time of electrolysis and current.展开更多
Transition metal oxide(TMO)nanoarrays are promising architecture designs for self-supporting oxygen electrodes to achieve high catalytic activities in lithium-oxygen(Li-O2)batteries.However,the poor conductive nature ...Transition metal oxide(TMO)nanoarrays are promising architecture designs for self-supporting oxygen electrodes to achieve high catalytic activities in lithium-oxygen(Li-O2)batteries.However,the poor conductive nature of TMOs and the confined growth of nanostructures on the limited surfaces of electrode substrates result in the low areal capacities of TMO nanoarray electrodes,which seriously deteriorates the intrinsically high energy densities of Li-O2 batteries.Herein,we propose a hybrid nanoarray architecture design that integrates the high electronic conductivity of carbon nanoflakes(CNFs)and the high catalytic activity of Co3 O4 nanosheets on carbon cloth(CC).Due to the synergistic effect of two differently featured components,the hybrid nanoarrays(Co3 O4-CNF@CC)achieve a high reversible capacity of3.14 mA h cm-2 that cannot be achieved by only single components.Further,CNFs grown on CC induce the three-dimensionally distributed growth of ultrafine Co3 O4 nanosheets to enable the efficient utilization of catalysts.Thus,with the high catalytic efficiency,hybrid Co3 O4-CNF@CC also achieves a more prolonged cycling life than pristine TMO nanoarrays.The present work provides a new strategy for improving the performance of nanoarray oxygen electrodes via the hybrid architecture design that integrates the intrinsic properties of each component and induces the three-dimensional distribution of catalysts.展开更多
This work creates a droplet battery model based on the electrolyte performance in the porous electrode, studies the current density on the mesoscopic scale, and explains how the mesoscopic structure of the porous elec...This work creates a droplet battery model based on the electrolyte performance in the porous electrode, studies the current density on the mesoscopic scale, and explains how the mesoscopic structure of the porous electrode influences the current density on the air-diffusion electrode. Near the three-phase line, there is a strong band containing nearly 80% current. For porous electrodes, the total current is proportional to the length of the strong band. Thus, it can be inferred that on the macroscopic scale, the longer the total length of the strong band on unit area is, the larger the current density is.展开更多
Hydrogen evolution reaction(HER)catalytic electrodes under actual working conditions show interesting mass transfer behaviors at solid(electrode)/liquid(electrolyte)/gas(hydrogen)three-phase interfaces.These behaviors...Hydrogen evolution reaction(HER)catalytic electrodes under actual working conditions show interesting mass transfer behaviors at solid(electrode)/liquid(electrolyte)/gas(hydrogen)three-phase interfaces.These behaviors are essential for forming a continuous and effective physical contact region between the electrolyte and the electrode and require further detailed understanding.Here,a case study on 1 T-2 H phase molybdenum disulfide(Mo S_(2))/carbon fiber paper(CFP)catalytic electrodes is performed.Rapid gas-liquid mass transfer at the interface for enhancing the working area stability and capillarity for increasing the electrode working area is found.The real scenario,wherein the energy utilization efficiency of the as-prepared non-noble metal catalytic electrode exceeds that of the noble metal catalytic electrode,is disclosed.Specifically,a fluid dynamics model is developed to investigate the behavior mechanism of hydrogen bubbles from generation to desorption on the catalytic electrode surface with different hydrophilic and hydrophobic properties.These new insights and theoretical evidence on the non-negligible three-phase interface behaviors will identify opportunities and motivate future research in high-efficiency,stability,and low-cost HER catalytic electrode development.展开更多
The development of an electrocatalyst based on abundant elements for the oxygen evolution reaction (OER) is important for water splitting associated with renewable energy sources. In this study, we develop an interc...The development of an electrocatalyst based on abundant elements for the oxygen evolution reaction (OER) is important for water splitting associated with renewable energy sources. In this study, we develop an interconnected Ni(Fe)OxHy nanosheet array on a stainless steel mesh (SSNNi) as an integrated OER electrode, without using any polymer binder. Benefiting from the well- defined three-dimensional (3D) architecture with highly exposed surface area, intimate contact between the active species and conductive substrate improved electron and mass transport capacity, facilitated electrolyte penetration, and improved mechanical stability. The SSNNi electrode also has excellent OER performance, including low overpotential, a small Tafel slope, and long-term durability in the alkaline electrolyte, making it one of the most promising OER electrodes developed.展开更多
Organic electrochemical transistors(OECTs)have garnered significant interest due to their ability to facilitate both ionic and electronic transport.A large proportion of research efforts thus far have focused on inves...Organic electrochemical transistors(OECTs)have garnered significant interest due to their ability to facilitate both ionic and electronic transport.A large proportion of research efforts thus far have focused on investigating high-performance materials that can serve as mixed ion doping and charge transport layers.However,relatively less attention has been given to the gateelectrode materials,which play a critical role in controlling operational voltage,redox processes,and stability,especially in the context of semiconductor-based OECTs working in accumulation mode.Moreover,the demand for planarity and flexibility in modern bioelectronic devices presents significant challenges for the commonly used Ag/AgCl electrodes in OECTs.Herein,we report the construction of high-performance accumulation-mode OECTs by utilizing a gate electrode made of three-dimensional(3D)-printed graphene oxide.The 3D-printed graphene oxide electrode incorporating one-dimensional(1D)carbon nanotubes,is directly printed using an aqueous-based ink and showcases exceptional mechanical flexibility and porosity properties,enabling high-throughput preparation for both top gates and integrated planar architecture,as well as fast ion/charge transport.OECTs with high performance comparable to that of Ag/AgCl-gated OECTs are thus achieved and present promising feasibility for electrocardiograph(ECG)signal recording.This provides a promising choice for the application of flexible bioelectronics in medical care and neurological recording.展开更多
Radical-containing porous organic polymers(POPs)have drawn great interest in various applications.However,the synthesis of radical POPs remains challenging due to the unstable nature of organic radicals.Here,a persist...Radical-containing porous organic polymers(POPs)have drawn great interest in various applications.However,the synthesis of radical POPs remains challenging due to the unstable nature of organic radicals.Here,a persistent and stable three-dimensional silicon-diacetylene porous organic radical polymer was synthesized via a classic Eglinton homocoupling reaction of tetraethynylsilane.The presence of carbon radicals in this material was confirmed by electron paramagnetic resonance,and its paramagnetic behavior was analyzed by a superconducting quantum interference device.This unique material has a low-lying lowest unoccupied molecular orbital(LUMO)energy level(−5.47 eV)and a small energy gap(ca.1.46 eV),which shows long-term cycling stability and excellent rate capability as an anode material for lithium-ion batteries,demonstrating potential application in energy fields.展开更多
Coating slurries for making anodes and cathodes of lithium batteries contain a large percentage of solid particles of different chemicals, sizes and shapes in highly viscous media. A thorough mixing of these slurries ...Coating slurries for making anodes and cathodes of lithium batteries contain a large percentage of solid particles of different chemicals, sizes and shapes in highly viscous media. A thorough mixing of these slurries poses a major challenge in the battery manufacturing process. Several types of mixing devices and mixing methods were examined. The conventional turbine stirrers or ball mill mixers could be adequately used for the preparation of anode slurries, but not suitable for cathode slurries. In this study, a newly three-dimensional mixer, in conjunction with a multi-stage mixing sequence was proposed. The mixing effectiveness was examined by means of rheological measurements and flow visualization techniques. Preliminary electrical performance results indicated that the battery obtained using the 3D mixing device with a multi-stage mixing sequence was more efficient to those obtained from conventional methods.展开更多
Three-dimensional(3D)grid porous electrodes introduce vertically aligned pores as a convenient path for the transport of lithium-ions(Li-ions),thereby reducing the total transport distance of Li-ions and improving the...Three-dimensional(3D)grid porous electrodes introduce vertically aligned pores as a convenient path for the transport of lithium-ions(Li-ions),thereby reducing the total transport distance of Li-ions and improving the reaction kinetics.Although there have been other studies focusing on 3D electrodes fabricated by 3D printing,there still exists a gap between electrode design and their electrochemical performance.In this study,we try to bridge this gap through a comprehensive investigation on the effects of various electrode parameters including the electrode porosity,active material particle diameter,electrode electronic conductivity,electrode thickness,line width,and pore size on the electrochemical performance.Both numerical simulations and experimental investigations are conducted to systematically examine these effects.3D grid porous Li_(4)Ti_(5)O_(12)(LTO)thick electrodes are fabricated by low temperature direct writing technology and the electrodes with the thickness of 1085μm and areal mass loading of 39.44 mg·cm^(−2) are obtained.The electrodes display impressive electrochemical performance with the areal capacity of 5.88 mAh·cm^(−2)@1.0 C,areal energy density of 28.95 J·cm^(−2)@1.0 C,and areal power density of 8.04 mW·cm^(−2)@1.0 C.This study can provide design guidelines for obtaining 3D grid porous electrodes with superior electrochemical performance.展开更多
A novel lightweight three-dimensional (3D) composite anode for a fast-charging] discharging Li-ion battery (LIB) was fabricated entirely using one-dimensional (1D) nanomaterials, i.e., Cu nanowires (CuNWs) and...A novel lightweight three-dimensional (3D) composite anode for a fast-charging] discharging Li-ion battery (LIB) was fabricated entirely using one-dimensional (1D) nanomaterials, i.e., Cu nanowires (CuNWs) and multi-walled C nanotubes (MWCNTs). Because of the excellent electrical conductivity, high-aspect ratio structures, and large surface areas of these nanomaterials, the CuNW-MWCNT composite (CNMC) with 3D structure provides significant advantages regarding the transport pathways for both electrons and ions. As an advanced binder-free anode, a CuNW-MWCNT composite film with a controllable thickness (~ 600 prn) exhibited a considerably low sheet resistance, and internal cell resistance. Furthermore, the random CuNW network with 3D structure acting as a rigid framework not only prevented MWCNT shrinkage and expansion due to aggregation and swelling but also minimized the effect of the volume change during the charge/discharge process. Both a half cell and a full cell of LIBs with the CNMC anode exhibited high specific capacities and Coulombic efficiendes, even at a high current. More importantly, we for the first time overcame the limitation of MWCNTs as anode materials for fast-charging]discharging LIBs (both half cells and full cells) by employing CuNWs, and the resulting anode can be applied to flexible LIBs. This innovative anode structure can lead to the development of ultrafast chargeable LIBs for electric vehides.展开更多
Easy fabrication of super-stretchable electrodes can pave the way for smart and wearable electronics.Using drop casting unidirectional nickel nanowires with polyurethane matrix,we fabricated a super-stretchable film w...Easy fabrication of super-stretchable electrodes can pave the way for smart and wearable electronics.Using drop casting unidirectional nickel nanowires with polyurethane matrix,we fabricated a super-stretchable film with high electric conductivity.The as-fabricated film can withstand a 300%tensile strain in the direction perpendicular to nanowires,owing to the transformation of percolating nanowire network from 2D to 3D.In contrast to the decreased film conductivities under large tension in most stretchable electrodes,which usually associate with fractures and irreversible deformations,our film conductivity can increase with the applied strain.This probably benefits from the enhanced electrical contacts between twisted nanowires under tension.The developed super-stretchable film with unprecedented behavior in this work sheds light on the facile fabrication of super-stretchable electrodes with durable performance.展开更多
The catalysis of Au thin film could be improved by fabrication of array structures in large area.In this work,nanoimprint lithography has been developed tofabricate flexible Au micro-array(MA)electrodes with~100%cover...The catalysis of Au thin film could be improved by fabrication of array structures in large area.In this work,nanoimprint lithography has been developed tofabricate flexible Au micro-array(MA)electrodes with~100%coverage.Advanced electron microscopy characterisations have directly visualised the atomic-scale three-dimensional(3D)nanostructures with a maximum depth of 6 atomic layers.In-situ observation unveils the crystal growth in the form of twinning.High double layer capacitance brings about large number of active sites on the Au thin film and has a logarithmic relationship with mesh grade.Electrochemistry testing shows that the Au MAs perform much better ethanol oxidation reaction than the planar sample;MAs with higher mesh grade have a greater active site utilisation ratio(ASUR),which is important to build electrochemical double layer for efficient charge transfer.Further improvement on ASUR is expected for greater electrocatalytic performance and potential application in direct ethanol fuel cell.展开更多
Pseudocapacitive transition metal oxides(PTMOs)have the advantages of high areal capacitance and material density suitable for high-energy supercapacitor devices,but they are typically marred by insufficient rate perf...Pseudocapacitive transition metal oxides(PTMOs)have the advantages of high areal capacitance and material density suitable for high-energy supercapacitor devices,but they are typically marred by insufficient rate performance,which in turn deteriorates cyclic stability at high current levels.Using the example of spinel manganese oxide,herein we demonstrate that a pseudocapacitive oxide electrode of remarkable rate performance and cyclic stability may be realized by adopting oxide nanocrystallites,which are derived based on a novel solution chemistry,and carbon additive(CA)nanoparticles with highly uniform of size distributions.Precisely controlling the particle morphology and size distribution of the active material and conductive additive(CA)in the nanometer range can maximize the density of active material-CA-electrolyte three-phase contact points,thus facilitating synchronized electron and cation flow for the completion of surface faradaic reactions.The resultant Mn3O4 pseudocapacitive electrode exhibits rate capability and cycle stability,including 60%capacity retention at 60 A g-1 and no capacity fade over 100000 cycles under dynamic current densities,far superior to the state-of-the-art PTMO electrodes.The electrode design strategy is in general applicable to pseudocapacitors containing poorly conductive active materials.展开更多
Lithium-sulfur batteries(LSBs)have emerged as a promising high energy density system in miniaturized energy storage devices.However,serious issues rooted in large volume change(80%),poor intrinsic conductivity,“shutt...Lithium-sulfur batteries(LSBs)have emerged as a promising high energy density system in miniaturized energy storage devices.However,serious issues rooted in large volume change(80%),poor intrinsic conductivity,“shuttle effect”of S cathode,and limited mass loading of traditional electrode still make it a big challenge to achieve high energy density LSBs in a limited footprint.Herein,an innovative carbon dioxide(CO_(2))assisted three-dimensional(3D)printing strategy is proposed to fabricate threedimensional lattice structured CO_(2)activated single-walled carbon nanotubes/S composite thick electrode(3DP S@CNTs-CO_(2))for high areal capacity LSBs.The 3D lattice structure formed by interwoven CNTs and printed regular macropores can not only act as fast electron transfer networks,ensuring good electronic conductivity of thick electrode,but is beneficial to electrolyte infiltration,effectively boosting ion diffusion kinetics even under a high-mass loading.In addition,the subsequent hightemperature CO_(2)in-situ etching can induce abundant nanopores on the wall of CNTs,which significantly promotes the sulfur loading as well as its full utilization as a result of shortened ion diffusion paths.Owing to these merits,the 3DP S@CNTs-CO_(2)electrode delivers an impressive mass loading of 10 mg·cm^(−2).More importantly,a desired attribute of linearly scale up in areal capacitance with increased layers is observed,up to an outstanding value of 5.74 mAh·cm^(−2),outperforming most reported LSBs that adopt strategies that physically inhibit polysulfides.This work provides a thrilling drive that stimulates the application of LSBs in new generation miniaturized electronic devices.展开更多
As a typical two-dimensional transition metal dichalcogenide, molybdenum disulfide (MoS2) is considered a potential anode material for sodium-ion batteries (NIBs), due to its relatively high theoretical capacity ...As a typical two-dimensional transition metal dichalcogenide, molybdenum disulfide (MoS2) is considered a potential anode material for sodium-ion batteries (NIBs), due to its relatively high theoretical capacity (~ 670 mAh·g--1). However, the low electrical conductivity of MoS2 and its dramatic volume change during charge/discharge lead to severe capacity degradation and poor cycling stability. In this work, we developed a facile, scalable, and effective synthesis method to embed nanosized MoS2 into a thin film of three-dimensional (3D)-interconnected carbon nanofibers (CNFs), producing a MoS2/CNFs film. The free-standing MoS2/CNFs thin film can be used as anode for NIBs without additional binders or carbon black. The MoS2/CNFs electrode exhibits a high reversible capacity of 260 mAh·g^-1, with an extremely low capacity loss of 0.05 mAh·g^-1 per cycle after 2,600 cycles at a current density of 1 A·g^-1. This enhanced sodium storage performance is attributed to the synergistic effect and structural advantages achieved by embedding MoS2 in the 3D-interconnected carbon matrix.展开更多
基金the National Key Research and Development Program of China(Grant Nos.2016YFA0200400 and 2016YFA0200800)the National Natural Science Foundation of China(Grant Nos.61888102,12074420,and 11674387)+1 种基金Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB33000000)Key Research Program of Frontier Sciences,Chinese Acdemy of Sciences(Grant No.QYZDJ-SSWSLH042).
文摘Three-dimensional(3D)vertical architecture transistors represent an important technological pursuit,which have distinct advantages in device integration density,operation speed,and power consumption.However,the fabrication processes of such 3D devices are complex,especially in the interconnection of electrodes.In this paper,we present a novel method which combines suspended electrodes and focused ion beam(FIB)technology to greatly simplify the electrodes interconnection in 3D devices.Based on this method,we fabricate 3D vertical core-double shell structure transistors with ZnO channel and Al_(2)O_(3) gate-oxide both grown by atomic layer deposition.Suspended top electrodes of vertical architecture could be directly connected to planar electrodes by FIB deposited Pt nanowires,which avoid cumbersome steps in the traditional 3D structure fabrication technology.Both single pillar and arrays devices show well behaved transfer characteristics with an Ion/Ioff current ratio greater than 106 and a low threshold voltage around 0 V.The ON-current of the 2×2 pillars vertical channel transistor was 1.2μA at the gate voltage of 3 V and drain voltage of 2 V,which can be also improved by increasing the number of pillars.Our method for fabricating vertical architecture transistors can be promising for device applications with high integration density and low power consumption.
基金Supported by the National Natural Science Foundation of China(Nos.50602003, 50502004)the Beijing Science & Technology Star Plans, China(No.2007B020)
文摘Degradation of o-chloronitrobenzene wastewater was experimentally investigated at a three-dimensional electrode(TDE) with granular activated carbon as the particle electrode, graphite as the anode, and stainless steel plate as the cathode. The kinetic model of o-chloronitrobenzene degradation was studied, and the effects of pH, electrolysis time, particle electrode, electrolyte concentration, and initial concentration of the solution on degradation efficiency were investigated to determine the optimal operating conditions. The degradation of o-chloronitrobenzene by oxidation at the TDE was monitored by chemical oxygen demand(COD) measurements, UV-Vis absorption, and high performance liquid chromatography(HPLC). COD degradation by electrochemical degradation followed pseudo-first order kinetics with respect to the concentration of o-chloronitrobenzene solutions. Optimal reaction conditions included 15 g of activated carbon as the particle electrode, 400 mg/L o-chloronitrobenzene solution containing 0.10 mol/L Na2SO4, pH=3, and 60 min of electrolysis. The UV-Vis absorption spectra and HPLC results illustrate that the benzene ring in o-chloronitrobenzene was rapidly broken down to form aliphatic substances through electrochemical degradation. COD degradation was approximately 98.5% at optimal conditions.
基金supported by the Climate Change Response Project (NRF-2019M1A2A2065612)the Brainlink Project (NRF2022H1D3A3A01081140)+3 种基金the NRF-2021R1A4A3027878 and the No. RS-2023-00212273 funded by the Ministry of Science and ICT of Korea via National Research Foundationresearch funds from Hanhwa Solutions Chemicals (1.220029.01)UNIST (1.190013.01)supported by the Institute for Basic Science (IBS-R019-D1)。
文摘Electrochemical N_(2) reduction reaction(eNRR) over Cu-based catalysts suffers from an intrinsically low activity of Cu for activation of stable N_(2) molecules and the limited supply of N_(2) to the catalyst due to its low solubility in aqueous electrolytes.Herein,we propose phosphorus-activated Cu electrocatalysts to generate electron-deficient Cu sites on the catalyst surface to promote the adsorption of N_(2) molecules.The eNRR system is further modified using a gas diffusion electrode(GDE) coated with polytetrafluoroethylene(PTFE) to form an effective three-phase boundary of liquid water-gas N_(2)-solid catalyst to facilitate easy access of N_(2) to the catalytic sites.As a result,the new catalyst in the flow-type cell records a Faradaic efficiency of 13.15% and an NH_(3) production rate of 7.69 μg h^(-1) cm^(-2) at-0.2 V_(RHE),which represent 3.56 and 59.2 times increases from those obtained with a pristine Cu electrode in a typical electrolytic cell.This work represents a successful demonstration of dual modification strategies;catalyst modification and N_(2) supplying system engineering,and the results would provide a useful platform for further developments of electrocatalysts and reaction systems.
基金Supported by the National High-Technology Research and Development Program(2003AA602140-2)the Important Scientific Re-search Project of Hubei Provincial Department of Education, China (2004D001)
文摘A method using three-dimensional electrode is applied to treat wastewater in oil fields, which contains polyacrylamide (PAM), for analogue. A best condition for electrolysis (I= 1.0 A, t=90 min, c=0.1%, m=980 g,φ=5 mm, d=5.0 cm) has been determined, under which the COD removal efficiency reached 96.0%, COD containing in wastewater reduced to 64.3 mg/L from 1 622.9 mg/L, the figure before treatment. Three categories of PAM-containing wastewater in production practice have been treated with the COD removal ratios being 87.5%, 82.4% and 84.7% respectively. Presence of H2O2 and ·OH are detected by means of Ti(IV)-5-Br-PADAP technique and colorimetry respectively. The concentration is positively proportional to the COD removal ratio and increases in accordance with increment of time of electrolysis and current.
基金supported by grants from the National Natural Science Foundation of China(Nos.21673169,51672205,51972257)the National Key Research Program of China(No.2016YFA0202602)+1 种基金the Research Start-Up Fund from Wuhan University of Technologythe Fundamental Research Funds for the Central Universities(WUT:No.2019IB003)。
文摘Transition metal oxide(TMO)nanoarrays are promising architecture designs for self-supporting oxygen electrodes to achieve high catalytic activities in lithium-oxygen(Li-O2)batteries.However,the poor conductive nature of TMOs and the confined growth of nanostructures on the limited surfaces of electrode substrates result in the low areal capacities of TMO nanoarray electrodes,which seriously deteriorates the intrinsically high energy densities of Li-O2 batteries.Herein,we propose a hybrid nanoarray architecture design that integrates the high electronic conductivity of carbon nanoflakes(CNFs)and the high catalytic activity of Co3 O4 nanosheets on carbon cloth(CC).Due to the synergistic effect of two differently featured components,the hybrid nanoarrays(Co3 O4-CNF@CC)achieve a high reversible capacity of3.14 mA h cm-2 that cannot be achieved by only single components.Further,CNFs grown on CC induce the three-dimensionally distributed growth of ultrafine Co3 O4 nanosheets to enable the efficient utilization of catalysts.Thus,with the high catalytic efficiency,hybrid Co3 O4-CNF@CC also achieves a more prolonged cycling life than pristine TMO nanoarrays.The present work provides a new strategy for improving the performance of nanoarray oxygen electrodes via the hybrid architecture design that integrates the intrinsic properties of each component and induces the three-dimensional distribution of catalysts.
文摘This work creates a droplet battery model based on the electrolyte performance in the porous electrode, studies the current density on the mesoscopic scale, and explains how the mesoscopic structure of the porous electrode influences the current density on the air-diffusion electrode. Near the three-phase line, there is a strong band containing nearly 80% current. For porous electrodes, the total current is proportional to the length of the strong band. Thus, it can be inferred that on the macroscopic scale, the longer the total length of the strong band on unit area is, the larger the current density is.
基金supported by the National Natural Science Foundation of China(No.62004051)the Natural Science Foundation of Heilongjiang province(No.LH2020F013)+1 种基金the China Postdoctoral Science Fund(No.2020M670909)the Heilongjiang Postdoctoral Science Fund(No.LBH-Z19017)。
文摘Hydrogen evolution reaction(HER)catalytic electrodes under actual working conditions show interesting mass transfer behaviors at solid(electrode)/liquid(electrolyte)/gas(hydrogen)three-phase interfaces.These behaviors are essential for forming a continuous and effective physical contact region between the electrolyte and the electrode and require further detailed understanding.Here,a case study on 1 T-2 H phase molybdenum disulfide(Mo S_(2))/carbon fiber paper(CFP)catalytic electrodes is performed.Rapid gas-liquid mass transfer at the interface for enhancing the working area stability and capillarity for increasing the electrode working area is found.The real scenario,wherein the energy utilization efficiency of the as-prepared non-noble metal catalytic electrode exceeds that of the noble metal catalytic electrode,is disclosed.Specifically,a fluid dynamics model is developed to investigate the behavior mechanism of hydrogen bubbles from generation to desorption on the catalytic electrode surface with different hydrophilic and hydrophobic properties.These new insights and theoretical evidence on the non-negligible three-phase interface behaviors will identify opportunities and motivate future research in high-efficiency,stability,and low-cost HER catalytic electrode development.
基金This work is financially supported by the National Natural Science Foundation of China (Nos. 51472209, U1401241, 51522101, 51471075, 5163100, and 51401084), and Specialized Research Fund for the Doctoral Program of Higher Education of China (No. 20110061120040).
文摘The development of an electrocatalyst based on abundant elements for the oxygen evolution reaction (OER) is important for water splitting associated with renewable energy sources. In this study, we develop an interconnected Ni(Fe)OxHy nanosheet array on a stainless steel mesh (SSNNi) as an integrated OER electrode, without using any polymer binder. Benefiting from the well- defined three-dimensional (3D) architecture with highly exposed surface area, intimate contact between the active species and conductive substrate improved electron and mass transport capacity, facilitated electrolyte penetration, and improved mechanical stability. The SSNNi electrode also has excellent OER performance, including low overpotential, a small Tafel slope, and long-term durability in the alkaline electrolyte, making it one of the most promising OER electrodes developed.
基金support from the National Natural Science Foundation of China(Nos.22222205,52173176,51773143,and 51821002)the Suzhou Key Laboratory of Surface and Interface Intelligent Matter(No.SZS2022011)supported by the Collaborative Innovation Center of Suzhou Nano Science&Technology,the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD),and the 111 Project.
文摘Organic electrochemical transistors(OECTs)have garnered significant interest due to their ability to facilitate both ionic and electronic transport.A large proportion of research efforts thus far have focused on investigating high-performance materials that can serve as mixed ion doping and charge transport layers.However,relatively less attention has been given to the gateelectrode materials,which play a critical role in controlling operational voltage,redox processes,and stability,especially in the context of semiconductor-based OECTs working in accumulation mode.Moreover,the demand for planarity and flexibility in modern bioelectronic devices presents significant challenges for the commonly used Ag/AgCl electrodes in OECTs.Herein,we report the construction of high-performance accumulation-mode OECTs by utilizing a gate electrode made of three-dimensional(3D)-printed graphene oxide.The 3D-printed graphene oxide electrode incorporating one-dimensional(1D)carbon nanotubes,is directly printed using an aqueous-based ink and showcases exceptional mechanical flexibility and porosity properties,enabling high-throughput preparation for both top gates and integrated planar architecture,as well as fast ion/charge transport.OECTs with high performance comparable to that of Ag/AgCl-gated OECTs are thus achieved and present promising feasibility for electrocardiograph(ECG)signal recording.This provides a promising choice for the application of flexible bioelectronics in medical care and neurological recording.
基金Financial support from the National Natural Science Foundation of China(grant nos.22131004,U21A20330,and 52173195)the“111”project(grant no.B18012)+1 种基金Jilin Provincial Department of Science and Technology(grant no.20210508048RQ)the Fundamental Research Funds for the Central Universities are gratefully acknowledged.
文摘Radical-containing porous organic polymers(POPs)have drawn great interest in various applications.However,the synthesis of radical POPs remains challenging due to the unstable nature of organic radicals.Here,a persistent and stable three-dimensional silicon-diacetylene porous organic radical polymer was synthesized via a classic Eglinton homocoupling reaction of tetraethynylsilane.The presence of carbon radicals in this material was confirmed by electron paramagnetic resonance,and its paramagnetic behavior was analyzed by a superconducting quantum interference device.This unique material has a low-lying lowest unoccupied molecular orbital(LUMO)energy level(−5.47 eV)and a small energy gap(ca.1.46 eV),which shows long-term cycling stability and excellent rate capability as an anode material for lithium-ion batteries,demonstrating potential application in energy fields.
文摘Coating slurries for making anodes and cathodes of lithium batteries contain a large percentage of solid particles of different chemicals, sizes and shapes in highly viscous media. A thorough mixing of these slurries poses a major challenge in the battery manufacturing process. Several types of mixing devices and mixing methods were examined. The conventional turbine stirrers or ball mill mixers could be adequately used for the preparation of anode slurries, but not suitable for cathode slurries. In this study, a newly three-dimensional mixer, in conjunction with a multi-stage mixing sequence was proposed. The mixing effectiveness was examined by means of rheological measurements and flow visualization techniques. Preliminary electrical performance results indicated that the battery obtained using the 3D mixing device with a multi-stage mixing sequence was more efficient to those obtained from conventional methods.
基金This work is supported by the National Natural Science Foundation of China(Nos.51705334 and 51975384)the Shenzhen Science&Technology Projects(Nos.JCYJ20180305125025855 and JCYJ20200109105618137).
文摘Three-dimensional(3D)grid porous electrodes introduce vertically aligned pores as a convenient path for the transport of lithium-ions(Li-ions),thereby reducing the total transport distance of Li-ions and improving the reaction kinetics.Although there have been other studies focusing on 3D electrodes fabricated by 3D printing,there still exists a gap between electrode design and their electrochemical performance.In this study,we try to bridge this gap through a comprehensive investigation on the effects of various electrode parameters including the electrode porosity,active material particle diameter,electrode electronic conductivity,electrode thickness,line width,and pore size on the electrochemical performance.Both numerical simulations and experimental investigations are conducted to systematically examine these effects.3D grid porous Li_(4)Ti_(5)O_(12)(LTO)thick electrodes are fabricated by low temperature direct writing technology and the electrodes with the thickness of 1085μm and areal mass loading of 39.44 mg·cm^(−2) are obtained.The electrodes display impressive electrochemical performance with the areal capacity of 5.88 mAh·cm^(−2)@1.0 C,areal energy density of 28.95 J·cm^(−2)@1.0 C,and areal power density of 8.04 mW·cm^(−2)@1.0 C.This study can provide design guidelines for obtaining 3D grid porous electrodes with superior electrochemical performance.
文摘A novel lightweight three-dimensional (3D) composite anode for a fast-charging] discharging Li-ion battery (LIB) was fabricated entirely using one-dimensional (1D) nanomaterials, i.e., Cu nanowires (CuNWs) and multi-walled C nanotubes (MWCNTs). Because of the excellent electrical conductivity, high-aspect ratio structures, and large surface areas of these nanomaterials, the CuNW-MWCNT composite (CNMC) with 3D structure provides significant advantages regarding the transport pathways for both electrons and ions. As an advanced binder-free anode, a CuNW-MWCNT composite film with a controllable thickness (~ 600 prn) exhibited a considerably low sheet resistance, and internal cell resistance. Furthermore, the random CuNW network with 3D structure acting as a rigid framework not only prevented MWCNT shrinkage and expansion due to aggregation and swelling but also minimized the effect of the volume change during the charge/discharge process. Both a half cell and a full cell of LIBs with the CNMC anode exhibited high specific capacities and Coulombic efficiendes, even at a high current. More importantly, we for the first time overcame the limitation of MWCNTs as anode materials for fast-charging]discharging LIBs (both half cells and full cells) by employing CuNWs, and the resulting anode can be applied to flexible LIBs. This innovative anode structure can lead to the development of ultrafast chargeable LIBs for electric vehides.
基金the National Key Research and Development Program of China(Grant No.2019YFA0705400)National Natural Science Foundation of China(Grant Nos.51535005,51472117,51702159)+4 种基金the Research Fund of State Key Laboratory of Mechanics and Control of Mechanical Structures(Grant Nos.MCMS-I-0418K01,MCMS-I-0419K01)the Fundamental Research Funds for the Central Universities(Grant Nos.NC2018001,NP2019301,NJ2019002)Natural Science Foundation of Jiangsu Province(Grant Nos.BK20170791,BK20180416)National and Jiangsu Postdoctoral Research Funds(Grant Nos.2017M610328,2018T110494 and 1701141B)A Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions。
文摘Easy fabrication of super-stretchable electrodes can pave the way for smart and wearable electronics.Using drop casting unidirectional nickel nanowires with polyurethane matrix,we fabricated a super-stretchable film with high electric conductivity.The as-fabricated film can withstand a 300%tensile strain in the direction perpendicular to nanowires,owing to the transformation of percolating nanowire network from 2D to 3D.In contrast to the decreased film conductivities under large tension in most stretchable electrodes,which usually associate with fractures and irreversible deformations,our film conductivity can increase with the applied strain.This probably benefits from the enhanced electrical contacts between twisted nanowires under tension.The developed super-stretchable film with unprecedented behavior in this work sheds light on the facile fabrication of super-stretchable electrodes with durable performance.
基金the MOE AcRF Tier 1 grant M4011528.The XRD and FEG-TEM characterisations were performed at Facility for Analysis,Characterisation,Testing and Simulation(FACTS)Labthe FEG-SEM/FIB characterisations were carried out at Microelectronics Reliability and Characterisation(MRC)Lab.
文摘The catalysis of Au thin film could be improved by fabrication of array structures in large area.In this work,nanoimprint lithography has been developed tofabricate flexible Au micro-array(MA)electrodes with~100%coverage.Advanced electron microscopy characterisations have directly visualised the atomic-scale three-dimensional(3D)nanostructures with a maximum depth of 6 atomic layers.In-situ observation unveils the crystal growth in the form of twinning.High double layer capacitance brings about large number of active sites on the Au thin film and has a logarithmic relationship with mesh grade.Electrochemistry testing shows that the Au MAs perform much better ethanol oxidation reaction than the planar sample;MAs with higher mesh grade have a greater active site utilisation ratio(ASUR),which is important to build electrochemical double layer for efficient charge transfer.Further improvement on ASUR is expected for greater electrocatalytic performance and potential application in direct ethanol fuel cell.
基金financially supported by the“Advanced Research Center for Green Materials Science and Technology”from The Featured Area Research Center Program within the framework of the Higher Education Sprout Project by Ministry of Science and Technology in Taiwan under the grants of MOST-108-3017-F-002002,and also of MOST-107-2221-E-002-106-MY3,MOST-108-2119-M-002-010,MOST-107-2923-E-011-002,MOST-108-3116-F-301-001-F
文摘Pseudocapacitive transition metal oxides(PTMOs)have the advantages of high areal capacitance and material density suitable for high-energy supercapacitor devices,but they are typically marred by insufficient rate performance,which in turn deteriorates cyclic stability at high current levels.Using the example of spinel manganese oxide,herein we demonstrate that a pseudocapacitive oxide electrode of remarkable rate performance and cyclic stability may be realized by adopting oxide nanocrystallites,which are derived based on a novel solution chemistry,and carbon additive(CA)nanoparticles with highly uniform of size distributions.Precisely controlling the particle morphology and size distribution of the active material and conductive additive(CA)in the nanometer range can maximize the density of active material-CA-electrolyte three-phase contact points,thus facilitating synchronized electron and cation flow for the completion of surface faradaic reactions.The resultant Mn3O4 pseudocapacitive electrode exhibits rate capability and cycle stability,including 60%capacity retention at 60 A g-1 and no capacity fade over 100000 cycles under dynamic current densities,far superior to the state-of-the-art PTMO electrodes.The electrode design strategy is in general applicable to pseudocapacitors containing poorly conductive active materials.
基金supported by the National Natural Science Foundation of China(Nos.51933007 and 51673123)the National Key Research and development Program of China(No.2017YFE0111500)the Program for Featured Directions of Engineering Multidisciplines of Sichuan University(No.2020SCUNG203).
文摘Lithium-sulfur batteries(LSBs)have emerged as a promising high energy density system in miniaturized energy storage devices.However,serious issues rooted in large volume change(80%),poor intrinsic conductivity,“shuttle effect”of S cathode,and limited mass loading of traditional electrode still make it a big challenge to achieve high energy density LSBs in a limited footprint.Herein,an innovative carbon dioxide(CO_(2))assisted three-dimensional(3D)printing strategy is proposed to fabricate threedimensional lattice structured CO_(2)activated single-walled carbon nanotubes/S composite thick electrode(3DP S@CNTs-CO_(2))for high areal capacity LSBs.The 3D lattice structure formed by interwoven CNTs and printed regular macropores can not only act as fast electron transfer networks,ensuring good electronic conductivity of thick electrode,but is beneficial to electrolyte infiltration,effectively boosting ion diffusion kinetics even under a high-mass loading.In addition,the subsequent hightemperature CO_(2)in-situ etching can induce abundant nanopores on the wall of CNTs,which significantly promotes the sulfur loading as well as its full utilization as a result of shortened ion diffusion paths.Owing to these merits,the 3DP S@CNTs-CO_(2)electrode delivers an impressive mass loading of 10 mg·cm^(−2).More importantly,a desired attribute of linearly scale up in areal capacitance with increased layers is observed,up to an outstanding value of 5.74 mAh·cm^(−2),outperforming most reported LSBs that adopt strategies that physically inhibit polysulfides.This work provides a thrilling drive that stimulates the application of LSBs in new generation miniaturized electronic devices.
基金This work was supported by the National Key Research and Development Program of China (No. 2016YFB0100305), the National Natural Science Foundation of China (Nos. 21373195 and 51622210), the Fundamental Research Funds for the Central Universities (No. WK3430000004), and the Collaborative Innovation Center of Suzhou Nano Science and Technology.
文摘As a typical two-dimensional transition metal dichalcogenide, molybdenum disulfide (MoS2) is considered a potential anode material for sodium-ion batteries (NIBs), due to its relatively high theoretical capacity (~ 670 mAh·g--1). However, the low electrical conductivity of MoS2 and its dramatic volume change during charge/discharge lead to severe capacity degradation and poor cycling stability. In this work, we developed a facile, scalable, and effective synthesis method to embed nanosized MoS2 into a thin film of three-dimensional (3D)-interconnected carbon nanofibers (CNFs), producing a MoS2/CNFs film. The free-standing MoS2/CNFs thin film can be used as anode for NIBs without additional binders or carbon black. The MoS2/CNFs electrode exhibits a high reversible capacity of 260 mAh·g^-1, with an extremely low capacity loss of 0.05 mAh·g^-1 per cycle after 2,600 cycles at a current density of 1 A·g^-1. This enhanced sodium storage performance is attributed to the synergistic effect and structural advantages achieved by embedding MoS2 in the 3D-interconnected carbon matrix.