Listeria monocytogenes(LM)is a dangerous foodborne pathogen for humans.One emerging and validated method of indirectly assessing LM in food is detecting 3-hydroxy-2-butanone(3H2B)gas.In this study,the synthesis of 3-(...Listeria monocytogenes(LM)is a dangerous foodborne pathogen for humans.One emerging and validated method of indirectly assessing LM in food is detecting 3-hydroxy-2-butanone(3H2B)gas.In this study,the synthesis of 3-(2-aminoethylamino)propyltrimethoxysilane(AAPTMS)functionalized hierarchical hollow TiO_(2)nanospheres was achieved via precise controlling of solvothermal reaction temperature and post-grafting route.The sensors based on as-prepared materials exhibited excellent sensitivity(480 Hz@50 ppm),low detection limit(100 ppb),and outstanding selectivity.Moreover,the evaluation of LM with high sensitivity and specificity was achieved using the sensors.Such stable three-dimensional spheres,whose distinctive hierarchical and hollow nanostructure simultaneously improved both sensitivity and response/recovery speed dramatically,were spontaneously assembled by nanosheets.Meanwhile,the moderate loadings of AAPTMS significantly improved the selectivity of sensors.Then,the gas-sensing mechanism was explored by utilizing thermodynamic investigation,Gaussian 16 software,and in situ diffuse reflectance infrared transform spectroscopy,illustrating the weak chemisorption between the-NHgroup and 3H2B molecules.These portable sensors are promising for real-time assessment of LM at room temperature,which will make a magnificent contribution to food safety.展开更多
The imperative quest for renewable energy sources and advanced energy storage technologies has arisen amidst the escalating perils of climate change and dwindling fossil fuel reserves.In the realm of energy storage te...The imperative quest for renewable energy sources and advanced energy storage technologies has arisen amidst the escalating perils of climate change and dwindling fossil fuel reserves.In the realm of energy storage technologies,asymmetric supercapacitor(ASC)has garnered significant attention owing to its high energy density and power density.In the quest for advanced electrode materials for ASC,the integration of 2D layered heterostructures on hierarchical porous carbon(HPC)substrates has emerged as a promising approach to enhance the electrochemical performance.Herein,a highly innovative hierarchical NiCo LDH/MoS_(2)/HPC heterostructure was successfully synthesized using a simple two-step hydrothermal method for the electrode materials of ASC.Benefiting from the unique hierarchical heterostructure of NiCo LDH/MoS_(2)/HPC composite and the synergistic effect between the components,it reveals an exceptional specific capacitance of 2368 F/g at 0.5 A/g in a three-electrode system,which significantly exceeds that of conventional supercapacitor electrodes.Additionally,the ASC device of NiCo LDH/MoS_(2)/HPC//HPC achieves remarkable specific capacitance of 236 F/g at 0.5 A/g and an impressive energy density of 84Wh/kg at a power density of 400 W/kg,as well as superior cyclic stability.This study not only demonstrates the effectiveness of incorporating MoS_(2) and NiCo LDH into a carbon-based framework for supercapacitor applications but also opens avenues for designing more efficient energy storage devices.展开更多
Zn-CO_(2)batteries(ZCBs)are promising for CO_(2)conversion and electric energy release.However,the ZCBs couple the electrochemical CO_(2)reduction(ECO_(2)R)with the oxygen evolution reaction and competitive hydrogen e...Zn-CO_(2)batteries(ZCBs)are promising for CO_(2)conversion and electric energy release.However,the ZCBs couple the electrochemical CO_(2)reduction(ECO_(2)R)with the oxygen evolution reaction and competitive hydrogen evolution reaction,which normally causes ultrahigh charge voltage and CO_(2)conversion efficiency attenuation,thereby resulting in~90%total power consumption.Herein,isolated FeN_(3)sites encapsulated in hierarchical porous carbon nanoboxes(Fe-HPCN,derived from the thermal activation process of ferrocene and polydopamine-coated cubic ZIF-8)were proposed for hydrazine-assisted rechargeable ZCBs based on ECO_(2)R(discharging process:CO_(2)+2H+→CO+H_(2)O)and hydrazine oxidation reaction(HzOR,charging process:N_(2)H_(4)+4OH−→N_(2)+4H_(2)O+4e^(−)).The isolated FeN_(3)endows the HzOR with a lower overpotential and boosts the ECO_(2)R with a 96%CO Faraday efficiency(FECO).Benefitting from the bifunctional ECO_(2)R and HzOR catalytic activities,the homemade hydrazine-assisted rechargeable ZCBs assembled with the Fe-HPCN air cathode exhibited an ultralow charge voltage(decreasing by~1.84 V),excellent CO selectivity(FECO close to 100%),and high 89%energy efficiency.In situ infrared spectroscopy confirmed that Fe-HPCN can generate rate-determining*N_(2)and*CO intermediates during HzOR and ECO_(2)R.This paper proposes FeN_(3)centers for bifunctional ECO_(2)R/HzOR performance and further presents the pioneering achievements of ECO_(2)R and HzOR for hydrazine-assisted rechargeable ZCBs.展开更多
The electrochemical reduction of carbon dioxide(CO_(2)RR)is a promising strategy for achieving carbon neutralization.The Ni-N_(4) site is well known as the active site in metal single atoms on N-doped carbon catalysts...The electrochemical reduction of carbon dioxide(CO_(2)RR)is a promising strategy for achieving carbon neutralization.The Ni-N_(4) site is well known as the active site in metal single atoms on N-doped carbon catalysts,while its symmetric charge distribution nature is not favorable for electron transfer and then hindering the efficient CO_(2)RR.Herein,we constructed a Ni SA/CNs single-atom catalyst.Notably,it features unique Ni-N_(4)-O active sites,featuring one axial O atom and four planar N atoms,constituting a broken symmetrical electronic structure of Ni-N_(4) sites.Furthermore,hierarchical pore structures were obtained with the assistance of NaNO_(3) pore-forming agent during thermal treatment process,which promote electronic and mass transfer.And the resulting high specific surface area can host more Ni-N_(4)-O active sites.These specialized active sites promote the key intermediate(∗CO)adsorption/desorption and suppresses hydrogen evolution.Consequently,the Ni SA/CNs catalyst exhibits a high turnover frequency(TOF)value,reaching 34,081 h^(-1) at-0.98 V vs.RHE.Additionally,it achieves an excellent CO Faradaic efficiency,exceeding 90%,over a wide potential range from-0.4 V to-1.0 V vs.RHE.This work not only offers a new method for the rational synthesize single-atom catalysts with unique Ni-N_(4)-O active sites,but also provides in-depth insight into the origin of catalytic activity of porous carbon-base catalysts.展开更多
ZnO with good lithiophilicity has widely been employed to modify the lithiophobic substrates and facilitate uniform lithium(Li)deposition.The overpotential of ZnO-derived Li anode during cycling depends on the lithiop...ZnO with good lithiophilicity has widely been employed to modify the lithiophobic substrates and facilitate uniform lithium(Li)deposition.The overpotential of ZnO-derived Li anode during cycling depends on the lithiophilicity of both LiZn and Li_(2)O products upon lithiation of ZnO.However,the striking differences in the lithiophilicity between Li_(2)O and LiZn would result in a high overpotential during cycling.In this research,the Al_(2)O_(3)/nZnO(n≥1)hybrid layers were precisely fabricated by atomic layer deposition(ALD)to regulate the lithiophilicity of ZnO phase and Li_(2)O/LiZn configuration—determining the actual Li loading amount and Li plating/stripping processes.Theoretically,the Li adsorption energy(E_(a))values of LiZn and Li_(2)O in the LiZn/Li_(2)O configuration are separately predicted as-2.789 and-3.447 eV.In comparison,the E_(a) values of LiZn,LiAlO_(2),and Li_(2)O in the LiZn/LiAlO_(2)/Li_(2)O configuration upon lithiation of Al_(2)O_(3)/8ZnO layer are calculated as-2.899,-3.089,and-3.208 eV,respectively.Importantly,a novel introduction of LiAlO_(2)into the LiZn/Li_(2)O configuration could enable the hierarchical Li plating/stripping and reduce the overpotentials during cycling.Consequently,the Al_(2)O_(3)/8ZnO-derived hybrid Li-metal anode could exhibit electrochemical performances superior to these of ZnO-derived Li anode in both symmetrical and full cells paired with a LiNi_(0.6)Co_(0.2)Mn_(0.2)O_(2)(NCM622)cathode.展开更多
Silicon-based(Si-based) materials offer more possibilities for generating new portable electronic devices due to their high specific capacities. However, their inferior electrical conductivity and volume expansion dur...Silicon-based(Si-based) materials offer more possibilities for generating new portable electronic devices due to their high specific capacities. However, their inferior electrical conductivity and volume expansion during cycling seriously limit their development. The optimum solution is to select specific materials to establish an exceptionally conductive and volume buffer structure,which can assist Si materials in developing their excellent lithium storage properties. In this study, Si particles were confined in TiO_(2)carbon fibers(TiO_(2)CFs) via electrospinning, after which they were encapsulated with MXene and Co-MoS_(2)(CMS) nanosheets to fabricate hierarchical ST-2@MXene@CMS films. TiO_(2)CF, MXene and CMS were employed to establish a coherent conductive network with one-, two-and three-dimensional electronic pathways to permit the unimpeded flow of electrons inside the electrode material. TiO_(2)CF, MXene and CMS acted precisely as multilayered buffers to ameliorate the volume change of Si particles during cycling. In addition, the CMS nanosheets were involved in lithium storage, contributing to the final electrochemical performance. Ultimately, the ST-2@MXene@CMS films served as free-standing electrodes, avoiding the impact of inactive interfaces on the electrochemical performance and fulfilling the lightweight requirement for new energy storage devices.展开更多
Electrocatalytic converting CO_(2) into chemical products has emerged as a promising approach to achieving carbon neutrality.Herein,we report a bismuth-based catalyst with high curvature terminal and amorphous layer w...Electrocatalytic converting CO_(2) into chemical products has emerged as a promising approach to achieving carbon neutrality.Herein,we report a bismuth-based catalyst with high curvature terminal and amorphous layer which fabricated via two-step electrodeposition achieves stable formate output in a wide voltage window of 600 mV.The Faraday efficiency(FE) of formate reached up to 99.4% at-0.8 V vs.RHE and it remained constant for more than 92 h at-15 mA cm^(-2).More intriguingly,FE formate of95.4% can be realized at a current density of industrial grade(-667.7 mA cm^(-2)) in flow cell.The special structure promoted CO_(2) adsorption and reduced its activation energy and enhanced the electric-thermal field and K^(+) enrichment which accelerated the reaction kinetics.In situ spectroscopy and theoretical calculation further confirmed that the introduction of amorphous structure is beneficial to adsorpting CO_(2)and stabling*OCHO intermediate.This work provides special insights to fabricate efficient electrocatalysts by means of structural and crystal engineering and makes efforts to realize the industrialization of bismuth-based catalysts.展开更多
Development of metal oxide semiconductors-based methane sensors with good response and low power consumption is one of the major challenges to realize the real-time monitoring of methane leakage.In this work,a self-as...Development of metal oxide semiconductors-based methane sensors with good response and low power consumption is one of the major challenges to realize the real-time monitoring of methane leakage.In this work,a self-assembled mulberry-like ZnO/SnO_(2)hierarchical structure is constructed by a two-step hydrothermal method.The resultant sensor works at room temperature with excellent response of~56.1%to 2000 ppm CH_(4)at 55%relative humidity.It is found that the strain induced at the ZnO/SnO_(2)interface greatly enhances the piezoelectric polarization on the ZnO surface and that the band bending results in the accumulation of chemically adsorbed O_(2)^(-)ions close to the interface,leading to significant improvement in the sensing performance of the methane gas sensor at room temperature.展开更多
Increasing the utilization efficiency of photogenerated electrons is highly recognized as one of the ef-ficient approaches to boost the photocatalytic CO_(2)conversion efficiency.Herein,ZIF-67-derived porous carbon(PC...Increasing the utilization efficiency of photogenerated electrons is highly recognized as one of the ef-ficient approaches to boost the photocatalytic CO_(2)conversion efficiency.Herein,ZIF-67-derived porous carbon(PC)material was employed for the construction of PC@ultrafine Bi_(12)O_(17)Br_(2)nanotubes(PC@BOB NTs)composites through a facile solvothermal synthesis in order to optimize the use of excited elec-trons in the BOB NTs.Photoelectrochemical characterization results revealed that the introduction of PC material achieved a faster charge separation rate in the PC@BOB composites,ensuring more photogener-ated electrons participate in the CO_(2)adsorption and activation process.Moreover,the pore structures of ZIF-67-derived PC material provided abundant confined spaces for the enrichment of CO_(2)molecules.Af-ter 5 h of Xenon lamp irradiation,PC@BOB composites exhibited obviously increased photocatalytic CO_(2)reduction activity in the pure water.When the addition amount of PC was 5 wt%,the PC@BOB-2 com-posite showed the highest CO evolution rate of 359.70μmol/g,which was 2.95 times higher than that of the pure BOB NTs.This work provides some independent insights into the applications of Metal-Organic Framework(MOF)-derived hierarchical porous structures to strengthen the CO_(2)enrichment,as well as the excited charge utilization efficiency,thus achieving a high solar-to-fuel conversion efficiency.展开更多
As anode materials for high-performance sodium-ion batteries and potassium-ion batteries,bimetallic selenides have attracted great concern due to their relatively high electrical conductivity and electrochemical activ...As anode materials for high-performance sodium-ion batteries and potassium-ion batteries,bimetallic selenides have attracted great concern due to their relatively high electrical conductivity and electrochemical activity.However,the formidable challenge in the reaction process is the large volume change,leading to the structural collapse of material,and eventually the decline in electrochemical performance.Herein,a composite of hierarchical CoSe_(2)–MoSe_(2) tubes anchored on reduced graphene oxide nanosheets(CoSe_(2)–MoSe_(2)/rGO)is designed by an in situ hydrothermal selenization treatment.Benefiting from the synergistic effects between CoSe_(2) and MoSe_(2),unique hierarchical structure,and effective reduced graphene oxide coating,the CoSe_(2)–MoSe_(2)/rGO exhibited improved reaction kinetics and structural stability,and thus good electrochemical properties.A combination mechanism of intercalation and conversion of CoSe_(2)–MoSe_(2)/rGO by forming NaxCoSe_(2) and Mo_(15)Se_(19) as intermediate states is put forward on the basis of in situ and ex situ XRD analyses.展开更多
Graphitic carbon nitride with nitrogen vacancies(NV-g-C_(3)N_(4))as a photocatalyst has been studied in solardriven energy conversion.However,expensive and rare noble metal co-catalysts such as Pt or Pd are required i...Graphitic carbon nitride with nitrogen vacancies(NV-g-C_(3)N_(4))as a photocatalyst has been studied in solardriven energy conversion.However,expensive and rare noble metal co-catalysts such as Pt or Pd are required in the photocatalytic H_(2)evolution.Consequently,the exploration of low-cost and high-performance co-catalysts to replace expensive and rare noble metals has received more and more attention.Herein,a novel hierarchical porous NiO anchored on NV-g-C_(3)N_(4)is successfully fabricated.The NV-g-C_(3)N_(4)/NiO photocatalysts exhibited outstanding H_(2)evolution rate under visible light irradiation in absence of noble metal cocatalysts.The optimized NV-g-C_(3)N_(4)/NiO(the mass ratio of NiO is*1.7%)achieved a maximum H2 evolution rate of 170.60 lmol·g^(-1)·h^(-1),exhibiting*8.3-fold enhancement as compared to that of NV-g-C3N4.NiO as co-catalyst provided more active sites for photocatalytic H2 evolution.Moreover,on the interface of NV-g-C_(3)N_(4)/NiO,an interface electric field is formed between NiO and host nitrogen-vacated g-C3N4,facilitating the transfer of the photogenerated electrons from NV-g-C_(3)N_(4)to NiO co-catalyst,resulting in significantly promoted migration and separation efficiency of the photogenerated charge carriers.展开更多
Graphitic carbon nitride(g-C_(3)N_(4))has attracted great interest in photocatalysis and photoelectrocatalysis.However,their poor hydrophilicity poses a great challenge for their applications in aqueous environment.He...Graphitic carbon nitride(g-C_(3)N_(4))has attracted great interest in photocatalysis and photoelectrocatalysis.However,their poor hydrophilicity poses a great challenge for their applications in aqueous environment.Here,we demonstrate synthesis of a hydrophilic bi-functional hierarchical architecture by the assembly of B-doped g-C_(3)N_(4)nanoplatelets.Such hierarchical B-doped g-C_(3)N_(4)material enables full utilization of their highly enhanced visible light absorption and photogenerated carrier separation in aqueous medium,leading to an excellent photocatalytic H_(2)O_(2)production rate of 4240.3μM g^(-1)h^(-1),2.84,2.64 and 2.13 times higher than that of the bulk g-C_(3)N_(4),g-C_(3)N_(4)nanoplatelets and bulk B doped g-C_(3)N_(4),respectively.Photoanodes based on these hierarchical architectures can generate an unprecedented photocurrent density of 1.72 m A cm^(-2)at 1.23 V under AM 1.5 G illumination for photoelectrochemical water splitting.This work makes a fundamental improvement towards large-scale exploitation of highly active,hydrophilic and stable metal-free g-C_(3)N_(4)photocatalysts for various practical applications.展开更多
Ingenious microstructure design and rational composition selection are effective approaches to realize high-performance microwave absorbers,and the advancement of biomimetic manufacturing provides a new strategy.In na...Ingenious microstructure design and rational composition selection are effective approaches to realize high-performance microwave absorbers,and the advancement of biomimetic manufacturing provides a new strategy.In nature,urchins are the animals without eyes but can“see”,because their special structure composed of regular spines and spherical photosensitive bodies“amplifies”the light-receiving ability.Herein,inspired by the above phenomenon,the biomimetic urchin-like Ti_(3)C_(2)T_(x)@ZnO hollow microspheres are rationally designed and fabricated,in which ZnO nanoarrays(length:~2.3μm,diameter:~100 nm)as the urchin spines are evenly grafted onto the surface of the Ti_(3)C_(2)T_(x) hollow spheres(diameter:~4.2μm)as the urchin spherical photosensitive bodies.The construction of gradient impedance and hierarchical heterostructures enhance the attenuation of incident electromagnetic waves.And the EMW loss behavior is further revealed by limited integral simulation calculations,which fully highlights the advantages of the urchin-like architecture.As a result,the Ti_(3)C_(2)T_(x)@ZnO hollow spheres deliver a strong reflection loss of−57.4 dB and broad effective absorption bandwidth of 6.56 GHz,superior to similar absorbents.This work provides a new biomimetic strategy for the design and manufacturing of advanced microwave absorbers.展开更多
MoS2/C composites are considered to have great application potential in sodium-ion batteries(SIBs).It is a challenging and meaningful subject that developing high-performance anode materials via combining MoS2 and car...MoS2/C composites are considered to have great application potential in sodium-ion batteries(SIBs).It is a challenging and meaningful subject that developing high-performance anode materials via combining MoS2 and carbon effectively to give free rein to their advantages in sodium ion storage.In this work,a novel MoS2-C material was designed by using cellulose nanocrystals(CNCs)as low-cost and green carbon source.3 D hierarchical microspheres(200-250 nm)constructed by ultrathin MoS2-C nanosheets were synthesized by synchronizing the pre-carbonization of CNCs with the formation of MoS2 in hydrothermal reaction and subsequent pyrolysis process.It is found that the ultrathin MoS2-C nanosheets were composed of CNCs-derived short-range ordered carbon and few-layered MoS2.Benefiting from the unique structure and robust combination of MoS2 and CNCs-derived carbon,the ultrathin MoS2-C nanosheets composite was proved to have excellent cycling stability and superior rate performance in sodium-ion half-cell test and have high first reversible specific capacity of 397.9 m Ah/g in full-cell test.This work provides a significant and effective pathway to prepare MoS2-C materials with excellent electrochemical performance for the application in large-scale energy storage systems.展开更多
Self-aggregation and sluggish transport kinetics of cathode materials would usually lead to the poor electrochemical performance for aqueous zinc-ion batteries(AZIBs).In this work,we report the construction of C@VO_(2...Self-aggregation and sluggish transport kinetics of cathode materials would usually lead to the poor electrochemical performance for aqueous zinc-ion batteries(AZIBs).In this work,we report the construction of C@VO_(2) composite via anti-aggregation growth and hierarchical porous carbon encapsulation.Both of the morphology of composite and pore structure of carbon layer can be regulated by tuning the adding amount of glucose.When acting as cathode applied for AZIBs,the C@VO_(2)-3:3 composite can deliver a high capacity of 281 m Ah g^(-1) at 0.2 A g^(-1).Moreover,such cathode also exhibits a remarkably rate capability and cyclic stability,which can release a specific capacity of 195 m Ah g^(-1) at 5 A g^(-1) with the capacity retention of 95.4%after 1000 cycles.Besides that,the evolution including the crystal structure,valence state and transport kinetics upon cycling were also deeply investigated.In conclusion,benefited from the synergistic effect of anti-aggregation morphology and hierarchical porous carbon encapsulation,the building of such C@VO_(2) composite can be highly expected to enhance the ion accessible site,boost the transport kinetics and thus performing a superior storage performance.Such design concept can be applied for other kinds of electrode materials and accelerating the development of highperformance AZIBs.展开更多
Photocatalytic carbon dioxide reduction reaction(CO_(2)RR)has been considered as one of most effective ways to solve the current energy crisis and environmental problems.However,the practical application of photocatal...Photocatalytic carbon dioxide reduction reaction(CO_(2)RR)has been considered as one of most effective ways to solve the current energy crisis and environmental problems.However,the practical application of photocatalytic CO_(2)RR is largely hindered by lock of efficient catalyst.Here,hierarchical titanium dioxide(TiO_(2))nanostructures with a highly active{001}surface were successfully synthesized by a facile approach from metal Ti powders.The obtained hierarchical TiO_(2)nanostructures were composed of TiO_(2)nanorods,which have a diameter about 5–10 nm and a length of several micrometers.It is found that these nanorods have exposed{001}facets.On the other hand,these hierarchical TiO_(2)nanostructures have a good light-harvesting efficiency with the help of TiO_(2)nanorods component and large specific surface area.Therefore,these hierarchical TiO_(2)nanostructures exhibit a much better activity for photocatalytic CO_(2)reduction than that of commercial TiO_(2)(P25).This high activity can be attributed to the synergistic effects of active surface,efficient charge transfer along nanorods and good light harvesting in the nanorod-hierarchical nanostructures.展开更多
The extensive use of toluene stimulates the effective detection by sensitive gas sensors based on unique materials.Here,hierarchical flower-like NiFe_(2)O_(4) with core-shell architecture was synthesized by a facile h...The extensive use of toluene stimulates the effective detection by sensitive gas sensors based on unique materials.Here,hierarchical flower-like NiFe_(2)O_(4) with core-shell architecture was synthesized by a facile hydrothermal method in the presence of urea and NH4 F.The controllable experiments indicated that the burr spheres and football-like samples were produced with individual urea or NH4 F.The flower-like NiFe_(2)O_(4) sensor exhibited outstanding sensitivity of 19.95 to 100×10^(-6) toluene with low detection limit(1×10^(-6)).Furthermore,the sensor showed superior sensing selectivity and longterm stability to toluene.The excellent sensing properties could largely arise from a combination of high surface area,numerous active sites,porous structures,and the native catalytic characteristics of NiFe2 O4 to facilitate toluene molecules adsorption,diffusion,and reaction.展开更多
Solar‐powered semiconductor photocatalysis is considered a powerful strategy for addressing environmental pollution and energy crisis.Nevertheless,the separation and transfer abilities of photogenerated photocatalyst...Solar‐powered semiconductor photocatalysis is considered a powerful strategy for addressing environmental pollution and energy crisis.Nevertheless,the separation and transfer abilities of photogenerated photocatalysts remain unsatisfactory.Herein,dual Ti_(3)C_(2)nanosheets/Ag co‐catalysts synergistically decorated hierarchical flower‐like TiO_(2)microspheres for boosting photocatalytic H_(2)production were fabricated by electrostatic self‐assembly and subsequent photoreduction procedures.The optimal Ag/Ti_(3)C_(2)/TiO_(2)composite demonstrated an excellent photocatalytic H_(2)‐production rate of 1024.72μmol g^(−1)h^(−1)under simulated solar irradiation,achieving nearly 40,2.3,and 1.8 folds with respect to that obtained on pristine TiO2,optimized Ti_(3)C_(2)/TiO_(2)composite,and Ag/TiO_(2)composite,respectively.The considerably improved photocatalytic H_(2)‐production activity is associated with the synergistic effect of the hierarchical flower‐like structure of TiO2,excellent electrical conductivity of Ti_(3)C_(2),and surface plasmon resonance effect of Ag,which enhances the light absorption capacity and promotes the separation and transfer of photogenerated carriers.This study provides insight into the design of high‐efficiency photocatalysts with dual co‐catalysts for solar H_(2)production.展开更多
Earth-abundant and nontoxic Sn-based materials have been regarded as promising catalysts for the electrochemical conversion of CO_(2)to C1 products,e.g.,CO and formate.However,it is still difficult for Snbased materia...Earth-abundant and nontoxic Sn-based materials have been regarded as promising catalysts for the electrochemical conversion of CO_(2)to C1 products,e.g.,CO and formate.However,it is still difficult for Snbased materials to obtain satisfactory performance at low-to-moderate overpotentials.Herein,a simple and facile electrospinning technique is utilized to prepare a composite of a bimetallic Sn-Co oxide/carbon matrix with a hollow nanotube structure(Sn Co-HNT).Sn Co-HNT can maintain>90%faradaic efficiencies for C1 products within a wide potential range from-0.6 VRHE to-1.2 VRHE,and a highest 94.1%selectivity towards CO in an H-type cell.Moreover,a 91.2%faradaic efficiency with a 241.3 m A cm^(-2)partial current density for C1 products could be achieved using a flow cell.According to theoretical calculations,the fusing of Sn/Co oxides on the carbon matrix accelerates electron transfer at the atomic level,causing electron deficiency of Sn centers and reversible variation between Co^(2+)and Co^(3+)centers.The synergistic effect of the Sn/Co composition improves the electron affinity of the catalyst surface,which is conducive to the adsorption and stabilization of key intermediates and eventually increases the catalytic activity in CO_(2)electroreduction.This study could provide a new strategy for the construction of oxide-derived catalysts for CO_(2)electroreduction.展开更多
Electromagnetic wave absorber is critical for reducing increasingly serious electromagnetic wave pollu-tion,however,the development of lightweight and broadband microwave absorbers remains a pressing challenge.We repo...Electromagnetic wave absorber is critical for reducing increasingly serious electromagnetic wave pollu-tion,however,the development of lightweight and broadband microwave absorbers remains a pressing challenge.We report here the rational design and synthesis of N-doped Ni@SiO_(2)/graphene composite con-structed from 3D interconnected porous graphene network and Ni@SiO_(2) core-shell architecture,which fulfills lightweight and broadband requirements while exhibiting highly efficient electromagnetic wave absorption.The porous graphene network,functioning both as lightweight support and dielectric medi-ator,was synthesized via NaCl template-assisted high-temperature calcination method.Upon uniformly attached with core-shell Ni@SiO_(2) on the surface,the resulting abundant heterogeneous interfaces con-structed by graphene-Ni and Ni-SiO_(2) strongly reinforce polarization loss.The presence of low dielectric SiO_(2) allows facile tuning of the complex permittivity of ternary composite by adjusting coating thick-ness to balance the attenuation ability and impedance matching.Moreover,further N-doping of graphene assists in the optimization of dielectric loss ability.Taking account of the advantages arising from the porous hierarchical architecture,multiple absorption centers and diverse interfaces,the lightweight com-posite exhibits an ultra-strong reflection loss(RL)value of-71.13 dB at 13.76 GHz with a thickness of 2.46 mm and broad effective absorption bandwidth of 7.04 GHz at a low filler content of 15 wt.%.More importantly,the effective absorption range covers 13.28 GHz(4.72-18 GHz)with the optimized thickness of 1.6-5 mm,representing 83%of the whole range of frequencies.Our results demonstrate that the novel 3D porous N-doped Ni@SiO_(2)/graphene network with hierarchical architecture is a promising candidate for high-performance electromagnetic wave absorption.展开更多
基金supported by the National Natural Science Foundation of China(No.32272399)the Shanghai Natural Science Foundation(No.21ZR1427500).
文摘Listeria monocytogenes(LM)is a dangerous foodborne pathogen for humans.One emerging and validated method of indirectly assessing LM in food is detecting 3-hydroxy-2-butanone(3H2B)gas.In this study,the synthesis of 3-(2-aminoethylamino)propyltrimethoxysilane(AAPTMS)functionalized hierarchical hollow TiO_(2)nanospheres was achieved via precise controlling of solvothermal reaction temperature and post-grafting route.The sensors based on as-prepared materials exhibited excellent sensitivity(480 Hz@50 ppm),low detection limit(100 ppb),and outstanding selectivity.Moreover,the evaluation of LM with high sensitivity and specificity was achieved using the sensors.Such stable three-dimensional spheres,whose distinctive hierarchical and hollow nanostructure simultaneously improved both sensitivity and response/recovery speed dramatically,were spontaneously assembled by nanosheets.Meanwhile,the moderate loadings of AAPTMS significantly improved the selectivity of sensors.Then,the gas-sensing mechanism was explored by utilizing thermodynamic investigation,Gaussian 16 software,and in situ diffuse reflectance infrared transform spectroscopy,illustrating the weak chemisorption between the-NHgroup and 3H2B molecules.These portable sensors are promising for real-time assessment of LM at room temperature,which will make a magnificent contribution to food safety.
基金supported by the National Key Research and Development Program of China(No.2021YFB3801200)the National Natural Science Foundation of China(Nos.22278051,22178044,and 22308043)the Science and Technology Innovation foundation of CNPC(No.2022DQ02–0608).
文摘The imperative quest for renewable energy sources and advanced energy storage technologies has arisen amidst the escalating perils of climate change and dwindling fossil fuel reserves.In the realm of energy storage technologies,asymmetric supercapacitor(ASC)has garnered significant attention owing to its high energy density and power density.In the quest for advanced electrode materials for ASC,the integration of 2D layered heterostructures on hierarchical porous carbon(HPC)substrates has emerged as a promising approach to enhance the electrochemical performance.Herein,a highly innovative hierarchical NiCo LDH/MoS_(2)/HPC heterostructure was successfully synthesized using a simple two-step hydrothermal method for the electrode materials of ASC.Benefiting from the unique hierarchical heterostructure of NiCo LDH/MoS_(2)/HPC composite and the synergistic effect between the components,it reveals an exceptional specific capacitance of 2368 F/g at 0.5 A/g in a three-electrode system,which significantly exceeds that of conventional supercapacitor electrodes.Additionally,the ASC device of NiCo LDH/MoS_(2)/HPC//HPC achieves remarkable specific capacitance of 236 F/g at 0.5 A/g and an impressive energy density of 84Wh/kg at a power density of 400 W/kg,as well as superior cyclic stability.This study not only demonstrates the effectiveness of incorporating MoS_(2) and NiCo LDH into a carbon-based framework for supercapacitor applications but also opens avenues for designing more efficient energy storage devices.
基金National Natural Science Foundation of China,Grant/Award Number:12274118Double First Class University Plan,Grant/Award Number:C176220100042+2 种基金National Natural Science Foundation of China-Yunnan Joint Fund,Grant/Award Number:U2002213Open Foundation of Guangxi Key Laboratory of Processing for Non-Ferrous Metals and Featured Materials,Grant/Award Number:2022GXYSOF10Henan Center for Outstanding Overseas Scientists,Grant/Award Number:GZS2023007.
文摘Zn-CO_(2)batteries(ZCBs)are promising for CO_(2)conversion and electric energy release.However,the ZCBs couple the electrochemical CO_(2)reduction(ECO_(2)R)with the oxygen evolution reaction and competitive hydrogen evolution reaction,which normally causes ultrahigh charge voltage and CO_(2)conversion efficiency attenuation,thereby resulting in~90%total power consumption.Herein,isolated FeN_(3)sites encapsulated in hierarchical porous carbon nanoboxes(Fe-HPCN,derived from the thermal activation process of ferrocene and polydopamine-coated cubic ZIF-8)were proposed for hydrazine-assisted rechargeable ZCBs based on ECO_(2)R(discharging process:CO_(2)+2H+→CO+H_(2)O)and hydrazine oxidation reaction(HzOR,charging process:N_(2)H_(4)+4OH−→N_(2)+4H_(2)O+4e^(−)).The isolated FeN_(3)endows the HzOR with a lower overpotential and boosts the ECO_(2)R with a 96%CO Faraday efficiency(FECO).Benefitting from the bifunctional ECO_(2)R and HzOR catalytic activities,the homemade hydrazine-assisted rechargeable ZCBs assembled with the Fe-HPCN air cathode exhibited an ultralow charge voltage(decreasing by~1.84 V),excellent CO selectivity(FECO close to 100%),and high 89%energy efficiency.In situ infrared spectroscopy confirmed that Fe-HPCN can generate rate-determining*N_(2)and*CO intermediates during HzOR and ECO_(2)R.This paper proposes FeN_(3)centers for bifunctional ECO_(2)R/HzOR performance and further presents the pioneering achievements of ECO_(2)R and HzOR for hydrazine-assisted rechargeable ZCBs.
基金financially supported by National High-Level Talent FundNational Natural Science Foundation of China (Nos. 22372138,22461160253,22121001,and 22072118)+3 种基金thank financial support from State Key Laboratory of Physical Chemistry of Solid Surfaces of Xiamen UniversityShenzhen Science and Technology Program (No. JCYJ20220530143401002)supported by Science and Technology Projects of Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province (IKKEM) (No. HRTP-[2022]-3)the Fundamental Research Funds for the Central Universities (No. 20720220008)
文摘The electrochemical reduction of carbon dioxide(CO_(2)RR)is a promising strategy for achieving carbon neutralization.The Ni-N_(4) site is well known as the active site in metal single atoms on N-doped carbon catalysts,while its symmetric charge distribution nature is not favorable for electron transfer and then hindering the efficient CO_(2)RR.Herein,we constructed a Ni SA/CNs single-atom catalyst.Notably,it features unique Ni-N_(4)-O active sites,featuring one axial O atom and four planar N atoms,constituting a broken symmetrical electronic structure of Ni-N_(4) sites.Furthermore,hierarchical pore structures were obtained with the assistance of NaNO_(3) pore-forming agent during thermal treatment process,which promote electronic and mass transfer.And the resulting high specific surface area can host more Ni-N_(4)-O active sites.These specialized active sites promote the key intermediate(∗CO)adsorption/desorption and suppresses hydrogen evolution.Consequently,the Ni SA/CNs catalyst exhibits a high turnover frequency(TOF)value,reaching 34,081 h^(-1) at-0.98 V vs.RHE.Additionally,it achieves an excellent CO Faradaic efficiency,exceeding 90%,over a wide potential range from-0.4 V to-1.0 V vs.RHE.This work not only offers a new method for the rational synthesize single-atom catalysts with unique Ni-N_(4)-O active sites,but also provides in-depth insight into the origin of catalytic activity of porous carbon-base catalysts.
基金supported by the National Key Research and Development Program of China(2021YFB2400202)the National Natural Science Foundation of China(52104313)+1 种基金the Key Research and Development Plan of Shaanxi(2024GH-YBXM-11)the Foshan Science and Technology Innovation Team Project(1920001004098).
文摘ZnO with good lithiophilicity has widely been employed to modify the lithiophobic substrates and facilitate uniform lithium(Li)deposition.The overpotential of ZnO-derived Li anode during cycling depends on the lithiophilicity of both LiZn and Li_(2)O products upon lithiation of ZnO.However,the striking differences in the lithiophilicity between Li_(2)O and LiZn would result in a high overpotential during cycling.In this research,the Al_(2)O_(3)/nZnO(n≥1)hybrid layers were precisely fabricated by atomic layer deposition(ALD)to regulate the lithiophilicity of ZnO phase and Li_(2)O/LiZn configuration—determining the actual Li loading amount and Li plating/stripping processes.Theoretically,the Li adsorption energy(E_(a))values of LiZn and Li_(2)O in the LiZn/Li_(2)O configuration are separately predicted as-2.789 and-3.447 eV.In comparison,the E_(a) values of LiZn,LiAlO_(2),and Li_(2)O in the LiZn/LiAlO_(2)/Li_(2)O configuration upon lithiation of Al_(2)O_(3)/8ZnO layer are calculated as-2.899,-3.089,and-3.208 eV,respectively.Importantly,a novel introduction of LiAlO_(2)into the LiZn/Li_(2)O configuration could enable the hierarchical Li plating/stripping and reduce the overpotentials during cycling.Consequently,the Al_(2)O_(3)/8ZnO-derived hybrid Li-metal anode could exhibit electrochemical performances superior to these of ZnO-derived Li anode in both symmetrical and full cells paired with a LiNi_(0.6)Co_(0.2)Mn_(0.2)O_(2)(NCM622)cathode.
基金financially supported by Shanghai Aerospace Science and Technology Innovation Foundation (No. SAST2020-105)。
文摘Silicon-based(Si-based) materials offer more possibilities for generating new portable electronic devices due to their high specific capacities. However, their inferior electrical conductivity and volume expansion during cycling seriously limit their development. The optimum solution is to select specific materials to establish an exceptionally conductive and volume buffer structure,which can assist Si materials in developing their excellent lithium storage properties. In this study, Si particles were confined in TiO_(2)carbon fibers(TiO_(2)CFs) via electrospinning, after which they were encapsulated with MXene and Co-MoS_(2)(CMS) nanosheets to fabricate hierarchical ST-2@MXene@CMS films. TiO_(2)CF, MXene and CMS were employed to establish a coherent conductive network with one-, two-and three-dimensional electronic pathways to permit the unimpeded flow of electrons inside the electrode material. TiO_(2)CF, MXene and CMS acted precisely as multilayered buffers to ameliorate the volume change of Si particles during cycling. In addition, the CMS nanosheets were involved in lithium storage, contributing to the final electrochemical performance. Ultimately, the ST-2@MXene@CMS films served as free-standing electrodes, avoiding the impact of inactive interfaces on the electrochemical performance and fulfilling the lightweight requirement for new energy storage devices.
基金financial support from the Zhejiang Provincial Natural Science Foundation of China(LQ22B060007)the National Natural Science Foundation of China(22206042)+2 种基金the Scientific Research Start-up of Hangzhou Normal University(2021GDL014)the Hebei Natural Science Foundation(E2021203047)the Hebei Provincial Foundation for Returness(C20200369)。
文摘Electrocatalytic converting CO_(2) into chemical products has emerged as a promising approach to achieving carbon neutrality.Herein,we report a bismuth-based catalyst with high curvature terminal and amorphous layer which fabricated via two-step electrodeposition achieves stable formate output in a wide voltage window of 600 mV.The Faraday efficiency(FE) of formate reached up to 99.4% at-0.8 V vs.RHE and it remained constant for more than 92 h at-15 mA cm^(-2).More intriguingly,FE formate of95.4% can be realized at a current density of industrial grade(-667.7 mA cm^(-2)) in flow cell.The special structure promoted CO_(2) adsorption and reduced its activation energy and enhanced the electric-thermal field and K^(+) enrichment which accelerated the reaction kinetics.In situ spectroscopy and theoretical calculation further confirmed that the introduction of amorphous structure is beneficial to adsorpting CO_(2)and stabling*OCHO intermediate.This work provides special insights to fabricate efficient electrocatalysts by means of structural and crystal engineering and makes efforts to realize the industrialization of bismuth-based catalysts.
基金financially supported by the National Natural Science Foundation of China(No.12174092,21902046,U21A20500)Overseas Expertise Introduction Center for Discipline Innovation(D18025)+1 种基金Hubei Provincial Department of Science and Technology(No.2019CFA079)Wuhan Science and Technology Bureau(2020010601012163)
文摘Development of metal oxide semiconductors-based methane sensors with good response and low power consumption is one of the major challenges to realize the real-time monitoring of methane leakage.In this work,a self-assembled mulberry-like ZnO/SnO_(2)hierarchical structure is constructed by a two-step hydrothermal method.The resultant sensor works at room temperature with excellent response of~56.1%to 2000 ppm CH_(4)at 55%relative humidity.It is found that the strain induced at the ZnO/SnO_(2)interface greatly enhances the piezoelectric polarization on the ZnO surface and that the band bending results in the accumulation of chemically adsorbed O_(2)^(-)ions close to the interface,leading to significant improvement in the sensing performance of the methane gas sensor at room temperature.
基金supported by the National Natural Science Foundation of China(Nos.22108108,22108106,22109055)China Postdoctoral Science Foundation(No.2022M721381).
文摘Increasing the utilization efficiency of photogenerated electrons is highly recognized as one of the ef-ficient approaches to boost the photocatalytic CO_(2)conversion efficiency.Herein,ZIF-67-derived porous carbon(PC)material was employed for the construction of PC@ultrafine Bi_(12)O_(17)Br_(2)nanotubes(PC@BOB NTs)composites through a facile solvothermal synthesis in order to optimize the use of excited elec-trons in the BOB NTs.Photoelectrochemical characterization results revealed that the introduction of PC material achieved a faster charge separation rate in the PC@BOB composites,ensuring more photogener-ated electrons participate in the CO_(2)adsorption and activation process.Moreover,the pore structures of ZIF-67-derived PC material provided abundant confined spaces for the enrichment of CO_(2)molecules.Af-ter 5 h of Xenon lamp irradiation,PC@BOB composites exhibited obviously increased photocatalytic CO_(2)reduction activity in the pure water.When the addition amount of PC was 5 wt%,the PC@BOB-2 com-posite showed the highest CO evolution rate of 359.70μmol/g,which was 2.95 times higher than that of the pure BOB NTs.This work provides some independent insights into the applications of Metal-Organic Framework(MOF)-derived hierarchical porous structures to strengthen the CO_(2)enrichment,as well as the excited charge utilization efficiency,thus achieving a high solar-to-fuel conversion efficiency.
基金supported by the National Natural Science Foundation of China(Grant No.21701144)。
文摘As anode materials for high-performance sodium-ion batteries and potassium-ion batteries,bimetallic selenides have attracted great concern due to their relatively high electrical conductivity and electrochemical activity.However,the formidable challenge in the reaction process is the large volume change,leading to the structural collapse of material,and eventually the decline in electrochemical performance.Herein,a composite of hierarchical CoSe_(2)–MoSe_(2) tubes anchored on reduced graphene oxide nanosheets(CoSe_(2)–MoSe_(2)/rGO)is designed by an in situ hydrothermal selenization treatment.Benefiting from the synergistic effects between CoSe_(2) and MoSe_(2),unique hierarchical structure,and effective reduced graphene oxide coating,the CoSe_(2)–MoSe_(2)/rGO exhibited improved reaction kinetics and structural stability,and thus good electrochemical properties.A combination mechanism of intercalation and conversion of CoSe_(2)–MoSe_(2)/rGO by forming NaxCoSe_(2) and Mo_(15)Se_(19) as intermediate states is put forward on the basis of in situ and ex situ XRD analyses.
基金This study was financially supported by the National Natural Science Foundation of China(Nos.22075072 and 52003079)Hubei Provincial Natural Science Foundation of China(No.2019CFB568).
文摘Graphitic carbon nitride with nitrogen vacancies(NV-g-C_(3)N_(4))as a photocatalyst has been studied in solardriven energy conversion.However,expensive and rare noble metal co-catalysts such as Pt or Pd are required in the photocatalytic H_(2)evolution.Consequently,the exploration of low-cost and high-performance co-catalysts to replace expensive and rare noble metals has received more and more attention.Herein,a novel hierarchical porous NiO anchored on NV-g-C_(3)N_(4)is successfully fabricated.The NV-g-C_(3)N_(4)/NiO photocatalysts exhibited outstanding H_(2)evolution rate under visible light irradiation in absence of noble metal cocatalysts.The optimized NV-g-C_(3)N_(4)/NiO(the mass ratio of NiO is*1.7%)achieved a maximum H2 evolution rate of 170.60 lmol·g^(-1)·h^(-1),exhibiting*8.3-fold enhancement as compared to that of NV-g-C3N4.NiO as co-catalyst provided more active sites for photocatalytic H2 evolution.Moreover,on the interface of NV-g-C_(3)N_(4)/NiO,an interface electric field is formed between NiO and host nitrogen-vacated g-C3N4,facilitating the transfer of the photogenerated electrons from NV-g-C_(3)N_(4)to NiO co-catalyst,resulting in significantly promoted migration and separation efficiency of the photogenerated charge carriers.
基金financially supported by the National Natural Science Foundation of China(U1663225)the Changjiang Scholar Program of Chinese Ministry of Education(IRT15R52)the program of Introducing Talents of Discipline to Universities-Plan 111(B20002)of Ministry of Science and Technology and the Ministry of Education of China and the project “Depollut Air”of Interreg V France-WallonieVlaanderen。
文摘Graphitic carbon nitride(g-C_(3)N_(4))has attracted great interest in photocatalysis and photoelectrocatalysis.However,their poor hydrophilicity poses a great challenge for their applications in aqueous environment.Here,we demonstrate synthesis of a hydrophilic bi-functional hierarchical architecture by the assembly of B-doped g-C_(3)N_(4)nanoplatelets.Such hierarchical B-doped g-C_(3)N_(4)material enables full utilization of their highly enhanced visible light absorption and photogenerated carrier separation in aqueous medium,leading to an excellent photocatalytic H_(2)O_(2)production rate of 4240.3μM g^(-1)h^(-1),2.84,2.64 and 2.13 times higher than that of the bulk g-C_(3)N_(4),g-C_(3)N_(4)nanoplatelets and bulk B doped g-C_(3)N_(4),respectively.Photoanodes based on these hierarchical architectures can generate an unprecedented photocurrent density of 1.72 m A cm^(-2)at 1.23 V under AM 1.5 G illumination for photoelectrochemical water splitting.This work makes a fundamental improvement towards large-scale exploitation of highly active,hydrophilic and stable metal-free g-C_(3)N_(4)photocatalysts for various practical applications.
基金This work was supported by National Natural Science Foundation of China(Grant Nos.52122302,51991351)Fundamental Research Funds for the Central Universities,Young Elite Scientists Sponsorship Program by CASTOpen access funding provided by Shanghai Jiao Tong University
文摘Ingenious microstructure design and rational composition selection are effective approaches to realize high-performance microwave absorbers,and the advancement of biomimetic manufacturing provides a new strategy.In nature,urchins are the animals without eyes but can“see”,because their special structure composed of regular spines and spherical photosensitive bodies“amplifies”the light-receiving ability.Herein,inspired by the above phenomenon,the biomimetic urchin-like Ti_(3)C_(2)T_(x)@ZnO hollow microspheres are rationally designed and fabricated,in which ZnO nanoarrays(length:~2.3μm,diameter:~100 nm)as the urchin spines are evenly grafted onto the surface of the Ti_(3)C_(2)T_(x) hollow spheres(diameter:~4.2μm)as the urchin spherical photosensitive bodies.The construction of gradient impedance and hierarchical heterostructures enhance the attenuation of incident electromagnetic waves.And the EMW loss behavior is further revealed by limited integral simulation calculations,which fully highlights the advantages of the urchin-like architecture.As a result,the Ti_(3)C_(2)T_(x)@ZnO hollow spheres deliver a strong reflection loss of−57.4 dB and broad effective absorption bandwidth of 6.56 GHz,superior to similar absorbents.This work provides a new biomimetic strategy for the design and manufacturing of advanced microwave absorbers.
基金supported by the National Natural Science Foundation of China(Grant No.51974114,51672075,and 21908049)Natural Science Foundation of Hunan Province and the Fundamental Research Funds for the Central Universities。
文摘MoS2/C composites are considered to have great application potential in sodium-ion batteries(SIBs).It is a challenging and meaningful subject that developing high-performance anode materials via combining MoS2 and carbon effectively to give free rein to their advantages in sodium ion storage.In this work,a novel MoS2-C material was designed by using cellulose nanocrystals(CNCs)as low-cost and green carbon source.3 D hierarchical microspheres(200-250 nm)constructed by ultrathin MoS2-C nanosheets were synthesized by synchronizing the pre-carbonization of CNCs with the formation of MoS2 in hydrothermal reaction and subsequent pyrolysis process.It is found that the ultrathin MoS2-C nanosheets were composed of CNCs-derived short-range ordered carbon and few-layered MoS2.Benefiting from the unique structure and robust combination of MoS2 and CNCs-derived carbon,the ultrathin MoS2-C nanosheets composite was proved to have excellent cycling stability and superior rate performance in sodium-ion half-cell test and have high first reversible specific capacity of 397.9 m Ah/g in full-cell test.This work provides a significant and effective pathway to prepare MoS2-C materials with excellent electrochemical performance for the application in large-scale energy storage systems.
基金financially supported by the National Natural Science Foundation of China(Nos.51774203)the Shenzhen Science and Technology Program(Nos.JCYJ20200109105801725)。
文摘Self-aggregation and sluggish transport kinetics of cathode materials would usually lead to the poor electrochemical performance for aqueous zinc-ion batteries(AZIBs).In this work,we report the construction of C@VO_(2) composite via anti-aggregation growth and hierarchical porous carbon encapsulation.Both of the morphology of composite and pore structure of carbon layer can be regulated by tuning the adding amount of glucose.When acting as cathode applied for AZIBs,the C@VO_(2)-3:3 composite can deliver a high capacity of 281 m Ah g^(-1) at 0.2 A g^(-1).Moreover,such cathode also exhibits a remarkably rate capability and cyclic stability,which can release a specific capacity of 195 m Ah g^(-1) at 5 A g^(-1) with the capacity retention of 95.4%after 1000 cycles.Besides that,the evolution including the crystal structure,valence state and transport kinetics upon cycling were also deeply investigated.In conclusion,benefited from the synergistic effect of anti-aggregation morphology and hierarchical porous carbon encapsulation,the building of such C@VO_(2) composite can be highly expected to enhance the ion accessible site,boost the transport kinetics and thus performing a superior storage performance.Such design concept can be applied for other kinds of electrode materials and accelerating the development of highperformance AZIBs.
基金Project(21872174)supported by the National Natural Science Foundation of ChinaProjects(2017CX003,20180018050001)supported by the Innovation-Driven Plan in Central South University,China+3 种基金Project supported by State Key Laboratory of Powder Metallurgy in Central South University,ChinaProject(JCYJ20180307151313532)supported by Shenzhen Science and Technology Innovation Project,ChinaProject supported by the Thousand Youth Talents Plan of ChinaProject supported by the Hundred Youth Talents Program of Hunan,China
文摘Photocatalytic carbon dioxide reduction reaction(CO_(2)RR)has been considered as one of most effective ways to solve the current energy crisis and environmental problems.However,the practical application of photocatalytic CO_(2)RR is largely hindered by lock of efficient catalyst.Here,hierarchical titanium dioxide(TiO_(2))nanostructures with a highly active{001}surface were successfully synthesized by a facile approach from metal Ti powders.The obtained hierarchical TiO_(2)nanostructures were composed of TiO_(2)nanorods,which have a diameter about 5–10 nm and a length of several micrometers.It is found that these nanorods have exposed{001}facets.On the other hand,these hierarchical TiO_(2)nanostructures have a good light-harvesting efficiency with the help of TiO_(2)nanorods component and large specific surface area.Therefore,these hierarchical TiO_(2)nanostructures exhibit a much better activity for photocatalytic CO_(2)reduction than that of commercial TiO_(2)(P25).This high activity can be attributed to the synergistic effects of active surface,efficient charge transfer along nanorods and good light harvesting in the nanorod-hierarchical nanostructures.
基金financially supported by the National Natural Science Foundation of China (No.11564042)the Precious Metal Materials Genetic Engineering Major Project of Yunnan Province (No.2019ZE001)+1 种基金the Project of the Department of Science and Technology of Yunnan Province (Nos.2018FB091 and 2019FB129)the Project of the Department of Education of Yunnan Province (No.2019J0001)。
文摘The extensive use of toluene stimulates the effective detection by sensitive gas sensors based on unique materials.Here,hierarchical flower-like NiFe_(2)O_(4) with core-shell architecture was synthesized by a facile hydrothermal method in the presence of urea and NH4 F.The controllable experiments indicated that the burr spheres and football-like samples were produced with individual urea or NH4 F.The flower-like NiFe_(2)O_(4) sensor exhibited outstanding sensitivity of 19.95 to 100×10^(-6) toluene with low detection limit(1×10^(-6)).Furthermore,the sensor showed superior sensing selectivity and longterm stability to toluene.The excellent sensing properties could largely arise from a combination of high surface area,numerous active sites,porous structures,and the native catalytic characteristics of NiFe2 O4 to facilitate toluene molecules adsorption,diffusion,and reaction.
文摘Solar‐powered semiconductor photocatalysis is considered a powerful strategy for addressing environmental pollution and energy crisis.Nevertheless,the separation and transfer abilities of photogenerated photocatalysts remain unsatisfactory.Herein,dual Ti_(3)C_(2)nanosheets/Ag co‐catalysts synergistically decorated hierarchical flower‐like TiO_(2)microspheres for boosting photocatalytic H_(2)production were fabricated by electrostatic self‐assembly and subsequent photoreduction procedures.The optimal Ag/Ti_(3)C_(2)/TiO_(2)composite demonstrated an excellent photocatalytic H_(2)‐production rate of 1024.72μmol g^(−1)h^(−1)under simulated solar irradiation,achieving nearly 40,2.3,and 1.8 folds with respect to that obtained on pristine TiO2,optimized Ti_(3)C_(2)/TiO_(2)composite,and Ag/TiO_(2)composite,respectively.The considerably improved photocatalytic H_(2)‐production activity is associated with the synergistic effect of the hierarchical flower‐like structure of TiO2,excellent electrical conductivity of Ti_(3)C_(2),and surface plasmon resonance effect of Ag,which enhances the light absorption capacity and promotes the separation and transfer of photogenerated carriers.This study provides insight into the design of high‐efficiency photocatalysts with dual co‐catalysts for solar H_(2)production.
基金supported by the National Natural Science Foundation of China(U21A20312,22172099,21975162,51902209)the Natural Science Foundation of Guangdong(2020A1515010840)the Shenzhen Science and Technology Program(SGDX20201103095802006,RCBS20200714114819161,JCYJ20190808111801674,JCYJ20200109105803806,RCYX20200714114535052)。
文摘Earth-abundant and nontoxic Sn-based materials have been regarded as promising catalysts for the electrochemical conversion of CO_(2)to C1 products,e.g.,CO and formate.However,it is still difficult for Snbased materials to obtain satisfactory performance at low-to-moderate overpotentials.Herein,a simple and facile electrospinning technique is utilized to prepare a composite of a bimetallic Sn-Co oxide/carbon matrix with a hollow nanotube structure(Sn Co-HNT).Sn Co-HNT can maintain>90%faradaic efficiencies for C1 products within a wide potential range from-0.6 VRHE to-1.2 VRHE,and a highest 94.1%selectivity towards CO in an H-type cell.Moreover,a 91.2%faradaic efficiency with a 241.3 m A cm^(-2)partial current density for C1 products could be achieved using a flow cell.According to theoretical calculations,the fusing of Sn/Co oxides on the carbon matrix accelerates electron transfer at the atomic level,causing electron deficiency of Sn centers and reversible variation between Co^(2+)and Co^(3+)centers.The synergistic effect of the Sn/Co composition improves the electron affinity of the catalyst surface,which is conducive to the adsorption and stabilization of key intermediates and eventually increases the catalytic activity in CO_(2)electroreduction.This study could provide a new strategy for the construction of oxide-derived catalysts for CO_(2)electroreduction.
基金supported by the National Natural Science Foundation of China (Nos.91963204 and 51871053)Shanghai Pujiang Program (No.19PJ1400200)the Fundamental Research Funds for the Central Universities (Nos.2232019G-07 and 2232020A-02)。
文摘Electromagnetic wave absorber is critical for reducing increasingly serious electromagnetic wave pollu-tion,however,the development of lightweight and broadband microwave absorbers remains a pressing challenge.We report here the rational design and synthesis of N-doped Ni@SiO_(2)/graphene composite con-structed from 3D interconnected porous graphene network and Ni@SiO_(2) core-shell architecture,which fulfills lightweight and broadband requirements while exhibiting highly efficient electromagnetic wave absorption.The porous graphene network,functioning both as lightweight support and dielectric medi-ator,was synthesized via NaCl template-assisted high-temperature calcination method.Upon uniformly attached with core-shell Ni@SiO_(2) on the surface,the resulting abundant heterogeneous interfaces con-structed by graphene-Ni and Ni-SiO_(2) strongly reinforce polarization loss.The presence of low dielectric SiO_(2) allows facile tuning of the complex permittivity of ternary composite by adjusting coating thick-ness to balance the attenuation ability and impedance matching.Moreover,further N-doping of graphene assists in the optimization of dielectric loss ability.Taking account of the advantages arising from the porous hierarchical architecture,multiple absorption centers and diverse interfaces,the lightweight com-posite exhibits an ultra-strong reflection loss(RL)value of-71.13 dB at 13.76 GHz with a thickness of 2.46 mm and broad effective absorption bandwidth of 7.04 GHz at a low filler content of 15 wt.%.More importantly,the effective absorption range covers 13.28 GHz(4.72-18 GHz)with the optimized thickness of 1.6-5 mm,representing 83%of the whole range of frequencies.Our results demonstrate that the novel 3D porous N-doped Ni@SiO_(2)/graphene network with hierarchical architecture is a promising candidate for high-performance electromagnetic wave absorption.
