Developing an efficient artificial photosynthetic system for transforming carbon dioxide and storing solar energy in the form of chemical bonds is one of the greatest challenges in modern chemistry.However,the limited...Developing an efficient artificial photosynthetic system for transforming carbon dioxide and storing solar energy in the form of chemical bonds is one of the greatest challenges in modern chemistry.However,the limited choice of catalysts with wide light absorption range,long-term stability and excellent selectivity for CO_(2) reduction makes the process sluggish.Here,a core-shell-structured nonnoble-metal Ni@In co-catalyst loaded p-type silicon nanowire arrays(SiNWs)for efficient CO_(2) reduction to formate is demonstrated.The formation rate and Faradaic efficiency of formate over the Ni@In/SiNWs catalyst reach 58μmol h^(-1) cm^(-2) and 87% under the irradiation of one simulated sunlight(AM 1.5 G,100 mW cm^(-2)),respectively,which are about 24 and 12 times those over the pristine SiNWs.The enhanced photoelectrocatalytic performance for CO_(2) reduction is attributed to the rational combination of Ni capable of effectively extracting the photogenerated electrons and In responsible for the selective activation of CO_(2).展开更多
All-solid-state Z-scheme photocatalysts for overall water splitting to evolve H_(2) is a promising strategy for efficient conversion of solar energy.However,most of these strategies require redox mediators.Herein,a di...All-solid-state Z-scheme photocatalysts for overall water splitting to evolve H_(2) is a promising strategy for efficient conversion of solar energy.However,most of these strategies require redox mediators.Herein,a direct Z-scheme photoelectrocatalytic electrode based on a WO_(3-x)nanowire-bridged TiO_(2)nanorod array heterojunction is constructed for overall water splitting,producing H_(2).The as-prepared WO_(3-x)/TiO_(2)nanorod array heterojunction shows photoelectrochemical(PEC)overall water splitting activity evolving both H_(2) and O_(2)under UV-vis light irradiation.An optimum PEC activity was achieved over a 1.67-WO_(3-x)/TiO_(2)photoelectrode yielding maximum H_(2) and O_(2)evolution rates roughly 11 times higher than that of pure TiO_(2)nanorods without any sacrificial agent or redox mediator.The role of oxygen vacancy in WO_(3-x)in affecting the H_(2) production rate was also comprehensively studied.The superior PEC activity of the WO_(3-x)/TiO_(2)electrode for overall water splitting can be ascribed to an efficient Z-scheme charge transfer pathway between the WO_(3-x)nanowires and TiO_(2)nanorods,the presence of oxygen vacancies in WO_(3-x),and a bias potential applied on the photoelectrode,resulting in effective spatial charge separation.This study provides a novel strategy for developing highly efficient PECs for overall water splitting.展开更多
Nitrogen reduction reaction(NRR)under ambient conditions is always a long-standing challenge in science,due to the extreme difficulty in breaking the strong N≡N triple bond.The key to resolving this issue undoubtedly...Nitrogen reduction reaction(NRR)under ambient conditions is always a long-standing challenge in science,due to the extreme difficulty in breaking the strong N≡N triple bond.The key to resolving this issue undoubtedly lies in searching superior catalysts to efficiently activate and hydrogenate the stable nitrogen molecules.We herein evaluate the feasibility of WP_(2) for N2 activation and reduction,and first demonstrate WP_(2) with an impressive ammonia yield rate of 7.13 lg h^(-1)cm^(-2),representing a promising W-based catalyst for NRR.DFT analysis further reveals that the NRR catalysis on WP_(2) proceeds in a distal reaction pathway,and the exceptional NRR activity is originated from superior surface electron energy level matching between WP_(2) and NRR potential which facilitates the interfacial proton-coupled electron transfer dynamics.The successfully unraveling the intrinsic catalytic mechanism of WP_(2) for NRR could offer a powerful platform to manipulate the NRR activity by tuning the electron energy levels.展开更多
CdS/SiO2 nanowire arrays and CdS nanobelts were synthesized by thermal evaporation of CdS and CdO mixture powders, with highly selective etching occurring on the silicon substrate surfaces. Study of the growth mechani...CdS/SiO2 nanowire arrays and CdS nanobelts were synthesized by thermal evaporation of CdS and CdO mixture powders, with highly selective etching occurring on the silicon substrate surfaces. Study of the growth mechanism of CdS/SiO2 nanowire arrays and the growth process of CdS nanobelts showed that the growth of CdS dendrites plays an important role in the formation of CdS/SiO2 nanowire arrays, and that the mechanism of CdS/SiO2 nanowire arrays growth was in good agreement with “self-assembling nanoelectrochemistry”. In the thermal evaporation process, an interaction between Si from silicon substrate and Cd took place.展开更多
Low-cost and flexible solid polymer electrolytes are promising in all-solid-state Li-metal batteries with high energy density and safety.However,both the low room-temperature ionic conductivities and the small Li^(+)t...Low-cost and flexible solid polymer electrolytes are promising in all-solid-state Li-metal batteries with high energy density and safety.However,both the low room-temperature ionic conductivities and the small Li^(+)transference number of these electrolytes significantly increase the internal resistance and overpotential of the battery.Here,we introduce Gd-doped CeO_(2) nanowires with large surface area and rich surface oxygen vacancies to the polymer electrolyte to increase the interaction between Gd-doped CeO_(2) nanowires and polymer electrolytes,which promotes the Li-salt dissociation and increases the concentration of mobile Li ions in the composite polymer electrolytes.The optimized composite polymer electrolyte has a high Li-ion conductivity of 5×10^(-4)4 S cm^(-1) at 30℃ and a large Li+transference number of 0.47.Moreover,the composite polymer electrolytes have excellent compatibility with the metallic lithium anode and high-voltage LiNi_(0.8)Mn _(0.1)Co_(0.1)O_(2)(NMC)cathode,providing the stable cycling of all-solid-state batteries at high current densities.展开更多
Spinel MnCo_(2)O_(4) is a promising energy storage candidate as anode materials in lithium-ion batteries owing to synergistic effects of two intrinsic solid-state redox couples.However,low conductivity,poor rate capac...Spinel MnCo_(2)O_(4) is a promising energy storage candidate as anode materials in lithium-ion batteries owing to synergistic effects of two intrinsic solid-state redox couples.However,low conductivity,poor rate capacity and rapid capacity fading have seriously impaired its practical applications.To overcome the inferiorities,urchin-like MnCo_(2)O_(4)@C core–shell nanowire arrays have been fabricated directly within a porous copper current collector via a facile hydrothermal method followed by a chemical vapor deposition carbonization process.In a typical nanowire,the core is composed of interconnected MnCo_(2)O_(4)nanoparticles and the shell shows as a thin amorphous carbon layer.The integrated MnCo_(2)O_(4)@C/Cu structure could act as working anodes without using additives or polymer binders.While MnCo_(2)O_(4)@C/Cu possesses slightly longer Li-ion insertion/desertion pathway than that of MnCo_(2)O_(4)/Cu,the carbon shell could effectively prevent the pulverization of MnCo_(2)O_(4) and lower down charge transfer resistance and actively participate in Li-ion cycles.The rearrangement of carbon atoms during lithiation/delithiation cycling could inhibit the formation of passive solid electrolyte interphase films.As a result,the MnCo_(2)O_(4)@C/Cu electrode presents superior rate capacity(600 mAh·g^(−1) at 1 A·g^(−1)) and better stability(797 mAh·g^(−1) after 200 cycles at 100 mA·g^(−1)).The excellent reversible Li ion storage capacity,cycling stability and rate capacity endow MnCo_(2)O_(4)@C/Cu great potential as stable and high output integrated anode materials in Li-ion batteries.展开更多
This paper reports a simple yet efficient method for the synthesis of hierarchical TiO2-B nanowire@α-Fe2O3 nanothorn core-branch arrays based on a stepwise hydrothermal approach. The as-fabricated hybrid arrays show ...This paper reports a simple yet efficient method for the synthesis of hierarchical TiO2-B nanowire@α-Fe2O3 nanothorn core-branch arrays based on a stepwise hydrothermal approach. The as-fabricated hybrid arrays show impressive performance as a high-capacity anode for lithium-ion batteries. The key design in this study is a core-branch hybrid architecture, which not only provides large surface active sites for lithium ion insertion/extraction, but also enables fast charge transport owing to the reduced diffusion paths for both electrons and lithium ions. The peculiar combination of attributes of TiO2 (good structural stability) and Fe2O3 (large specific capacity) provides the hybrid array electrodes with several desirable electrochemical features: large reversible capacity (-800 mA.h.g^-1 for specific mass capacity and -750 μA.h-cm^-2 for specific areal" capacity), good cycling stability, and high rate capability. The impressive electrochemical performance, together with the facile synthesis procedure, may provide an efficient platform to integrate the TiO2 nanowire@Fe2O3 nanothorn core-branch arrays as a three-dimensional thin film electrode for lithium-ion microbatteries.展开更多
Highly ordered Cu2O coated silicon nanowire arrays (SiNWAs) were fabricated as photocatalyst via depositing Cu nanoparticles on silver-assisted electroless-etched SiNWAs and subsequently annealing. The as-prepared s...Highly ordered Cu2O coated silicon nanowire arrays (SiNWAs) were fabricated as photocatalyst via depositing Cu nanoparticles on silver-assisted electroless-etched SiNWAs and subsequently annealing. The as-prepared samples have been characterized by scanning electron microscopy, X-ray diffraction and UV-VIS-NIR spectrophotometry. The photocatalytic properties of the Cu2O coated SiNWAs were investigated by degradation of Rhodamine B (RhB) under simulated solar light with a cut-off filter (λ 〉 420 nm). The results indicated that H2O2 could greatly improve the photocatalytic properties of Cu2O coated SiNWAs, and exhibited strong synergy effect between them. The hybrid nanowire arrays will be promising photocatalytic materials in the field of energy and environment.展开更多
Vertically aligned TiO2/SrTiO3 core–shell heterostructured nanowire arrays with different shell thicknesses(5–40 nm)were fabricated on fluorine-doped tin oxide substrate via a hydrothermal process.Microstructural ch...Vertically aligned TiO2/SrTiO3 core–shell heterostructured nanowire arrays with different shell thicknesses(5–40 nm)were fabricated on fluorine-doped tin oxide substrate via a hydrothermal process.Microstructural characterization demonstrated that the TiO2 nanowires were uniformly coated by the singlecrystal SrTiO3 shell,where continuous and large-area interface could be clearly observed.By this means,significantly enhanced photoelectrochemical water splitting properties(0.78 mA·cm^-2 at 1.23 V vs.RHE)were successfully realized in well-designed sample(with a shell thickness of 5–10 nm)compared with those of pristine TiO2(0.38 mA·cm^-2 at 1.23 V vs.RHE).The improvement of photoelectrochemical properties was attributed to the improved charge injection and charge separation,which are calculated by the results of water oxidation and sulfite oxidation measurements.Based on these results,a mechanism was proposed that SrTiO3 shell acted as an electron–hole separation layer to improve the photocurrent density.On the other hand,the sample with an over-thick SrTiO3 shell(20–40 nm)exhibited slightly reduced photoelectrochemical properties(0.66 mA·cm^-2),which could be explained by the increase of the recombination rate in thethicker SrTiO3 shell.This work provided a facile strategy to improve and modulate the photoelectrochemical performance of heterostructured photoanodes.展开更多
In this paper, hierarchical mesoporous Co3O4@ZnCo2O4 hybrid nanowire arrays(NWAs) on Ni foam were prepared through a two-step hydrothermal process associated with successive annealing treatment. The Co3O4@ZnCo2O4 hy...In this paper, hierarchical mesoporous Co3O4@ZnCo2O4 hybrid nanowire arrays(NWAs) on Ni foam were prepared through a two-step hydrothermal process associated with successive annealing treatment. The Co3O4@ZnCo2O4 hybrid NWAs exhibited excellent electrochemical performances with a high specific capacity of 1,240.5 C g^-1 at a current density of 2 mA cm^-2, with rate capability of 59.0%shifting from 2 to 30 mA cm^-2, and only a 9.1% loss of its capacity even after 3,000 cycles at a consistent current density of 10 mA cm^-2. An asymmetric supercapacitor(Co3O4@ZnCo2O4 NWAs||activated carbon) was fabricated and exhibited a high specific capacity of 168 C g^-1 at a current density of 1 A g^-1. And a preferable energy density of 37.3 W h kg^-1 at a power density of 800 W kg^-1 was obtained. The excellent electrochemical performances indicate the promising potential application of the hierarchical mesoporous Co3O4@ZnCo2O4 hybrid NWAs in energy storage field.展开更多
The advancement of cost-effective and selective electrocatalyst towards CO_(2) to CO conversion is crucial for renewable energy conversion and storage,thus to achieve carbon-neutral cycle in a sustainable manner.In th...The advancement of cost-effective and selective electrocatalyst towards CO_(2) to CO conversion is crucial for renewable energy conversion and storage,thus to achieve carbon-neutral cycle in a sustainable manner.In this communication,we report that CujSb decorated Cu nanowire arrays on Cu foil act as a highly active and selective electrocatalyst for CO_(2) to CO conversion.In CO_(2)-saturated 0.1 M KHCO_(3),it achieves a high Faraday efficiency(FE)of 86.5%for CO,at-0.90 V vs.reversible hydrogen electrode(RHE).The H_(2)/CO ratio is tunable from 0.08:1 to 5.9:1 by adjusting the potential.It is worth noting that HCOO-product was totally suppressed on such catalyst,compared with Sb counterpart.The improving selectivity for CO could be attributed to the bimetallic effect and nanowire arrays structure.展开更多
The successful development of Li-O_2 battery technology depends on developing a stable and efficient cathode. As an important step toward this goal, for the first time, we report the development of CeO_2 nanoparticles...The successful development of Li-O_2 battery technology depends on developing a stable and efficient cathode. As an important step toward this goal, for the first time, we report the development of CeO_2 nanoparticles modified NiCo_2O_4 nanowire arrays(NWAs) grown on the carbon textiles as a new carbon-free and binder-free cathode system. In this study, the Li-O_2 battery with the CeO_2@NiCo_2O_4 NWAs has exhibited much reduced overpotentials, a high discharge capacity, an improved cycling stability,outperforming the Li-O_2 battery with NiCo_2O_4 NWAs. These improvements can be attributed to both the tailored morphology of discharge product and improved oxygen reduction reaction(ORR) and oxygen evolution reaction(OER) activity after CeO_2 NPs deposition. To a considerable extent, this idea of cathode construction including structure design and composition optimization can provide guidance for further researches in developing more powerful cathode for Li-O_2 battery.展开更多
TiO2 nanowire arrays were successfully fabricated by liquid-phase deposition method using porous alumina templates. The obtained TiO2 nanowires were characterized using Raman spectroscopy, X-ray diffraction (XRD), s...TiO2 nanowire arrays were successfully fabricated by liquid-phase deposition method using porous alumina templates. The obtained TiO2 nanowires were characterized using Raman spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), field emission scanning electron microscopy (FE- SEM), transmission electron microscopy (TEM), and selected area electron diffraction (SAED) analysis. Results of electron microscopic observations indicated that the nanowires were smooth and uniform with a diameter of about 50-80 nm and several micrometers in length. SAED, Raman, and XRD mea- surements showed that TiO2 nanowires were single-crystalline with a pure rutile structure after heating at 800 ~C for 10 h. In this situation, the nanowire constituents grew preferentially along the 〈001〉 direction. Furthermore, the formation process and mechanistic study of the Ti02 nanowire arrays were proposed and discussed in detail. The nanowires are clearly produced by the deposition of TiO2 particles on the inner wall of the template nanochannels.展开更多
It is a huge challenge for metal oxide semiconductor gas sensors to inspect volatile organic compounds(VOCs)at room temperature(RT).Herein,the effective utilization of cerium oxide(CeO_(2))nanowires for RT detection o...It is a huge challenge for metal oxide semiconductor gas sensors to inspect volatile organic compounds(VOCs)at room temperature(RT).Herein,the effective utilization of cerium oxide(CeO_(2))nanowires for RT detection of VOCs was realized via regulating its surface chemical state.Oxygen vacancy engineering on CeO_(2) nanowires,synthesized via hydrothermal method,can be manipulated by annealing under various controlled atmospheres.The sample annealed under 5%H_(2)+95%Ar condition exhibited outstanding RT sensing properties,displaying a high response of 16.7 towards 20 ppm linalool,a fast response and recovery time(16 and 121 s,respectively),and a low detection of limit of 0.54 ppm.The enhanced sensing performance could be ascribed for the synergistic effects of its nanowire morphology,the large specific surface area(83.95 m^(2)/g),and the formation of extensive oxygen vacancy accompanied by an increase in Ce^(3+).Additionally,the practicability of the sensor was verified via two varieties of rice(Indica and Japonica rice)stored in various periods(1,3,5,7,15,and 30 d).The experimental results revealed that the sensor was able to distinguish Indica rice from Japonica rice.Accordingly,the as-developed sensor delivers a strategic material to develop high-performance RT electronic nose equipment for monitoring rice quality.展开更多
基金supported by the National Natural Science Foundation of China(Nos.21972115,91945301,21690082 and 21503176)the China Postdoctoral Science Foundation(Nos.2015M570555,2016T90597)。
文摘Developing an efficient artificial photosynthetic system for transforming carbon dioxide and storing solar energy in the form of chemical bonds is one of the greatest challenges in modern chemistry.However,the limited choice of catalysts with wide light absorption range,long-term stability and excellent selectivity for CO_(2) reduction makes the process sluggish.Here,a core-shell-structured nonnoble-metal Ni@In co-catalyst loaded p-type silicon nanowire arrays(SiNWs)for efficient CO_(2) reduction to formate is demonstrated.The formation rate and Faradaic efficiency of formate over the Ni@In/SiNWs catalyst reach 58μmol h^(-1) cm^(-2) and 87% under the irradiation of one simulated sunlight(AM 1.5 G,100 mW cm^(-2)),respectively,which are about 24 and 12 times those over the pristine SiNWs.The enhanced photoelectrocatalytic performance for CO_(2) reduction is attributed to the rational combination of Ni capable of effectively extracting the photogenerated electrons and In responsible for the selective activation of CO_(2).
基金supported by the National Key Research and Development Program of China(2019YFA0705400 and 2019YFD0901100)the National Natural Science Foundation of China(21991151,21925404,and 21775127)+1 种基金the“111”Project(B17027)Guangdong Basic and Applied Basic Research Foundation(2020A1515010510)。
文摘All-solid-state Z-scheme photocatalysts for overall water splitting to evolve H_(2) is a promising strategy for efficient conversion of solar energy.However,most of these strategies require redox mediators.Herein,a direct Z-scheme photoelectrocatalytic electrode based on a WO_(3-x)nanowire-bridged TiO_(2)nanorod array heterojunction is constructed for overall water splitting,producing H_(2).The as-prepared WO_(3-x)/TiO_(2)nanorod array heterojunction shows photoelectrochemical(PEC)overall water splitting activity evolving both H_(2) and O_(2)under UV-vis light irradiation.An optimum PEC activity was achieved over a 1.67-WO_(3-x)/TiO_(2)photoelectrode yielding maximum H_(2) and O_(2)evolution rates roughly 11 times higher than that of pure TiO_(2)nanorods without any sacrificial agent or redox mediator.The role of oxygen vacancy in WO_(3-x)in affecting the H_(2) production rate was also comprehensively studied.The superior PEC activity of the WO_(3-x)/TiO_(2)electrode for overall water splitting can be ascribed to an efficient Z-scheme charge transfer pathway between the WO_(3-x)nanowires and TiO_(2)nanorods,the presence of oxygen vacancies in WO_(3-x),and a bias potential applied on the photoelectrode,resulting in effective spatial charge separation.This study provides a novel strategy for developing highly efficient PECs for overall water splitting.
基金financial support from the National Natural Science Foundation of China(Nos.21771169,11804325,11722543,11875258,11505187)the National Key Research and Development Program of China(2017YFA0206703)+3 种基金Anhui Provincial Natural Science Foundation(BJ2060190077)USTC start-up fundingRecruitment Program of Global Expertthe Fundamental Research Funds for the Central Universities(WK2060190074,WK2060190081,WK2310000066)。
文摘Nitrogen reduction reaction(NRR)under ambient conditions is always a long-standing challenge in science,due to the extreme difficulty in breaking the strong N≡N triple bond.The key to resolving this issue undoubtedly lies in searching superior catalysts to efficiently activate and hydrogenate the stable nitrogen molecules.We herein evaluate the feasibility of WP_(2) for N2 activation and reduction,and first demonstrate WP_(2) with an impressive ammonia yield rate of 7.13 lg h^(-1)cm^(-2),representing a promising W-based catalyst for NRR.DFT analysis further reveals that the NRR catalysis on WP_(2) proceeds in a distal reaction pathway,and the exceptional NRR activity is originated from superior surface electron energy level matching between WP_(2) and NRR potential which facilitates the interfacial proton-coupled electron transfer dynamics.The successfully unraveling the intrinsic catalytic mechanism of WP_(2) for NRR could offer a powerful platform to manipulate the NRR activity by tuning the electron energy levels.
基金Project supported by the National Reward Plan of Outstanding Youth Teacher, China and the Natural Science Foundation of Shanxi Prov-ince (No. 2004E17), China
文摘CdS/SiO2 nanowire arrays and CdS nanobelts were synthesized by thermal evaporation of CdS and CdO mixture powders, with highly selective etching occurring on the silicon substrate surfaces. Study of the growth mechanism of CdS/SiO2 nanowire arrays and the growth process of CdS nanobelts showed that the growth of CdS dendrites plays an important role in the formation of CdS/SiO2 nanowire arrays, and that the mechanism of CdS/SiO2 nanowire arrays growth was in good agreement with “self-assembling nanoelectrochemistry”. In the thermal evaporation process, an interaction between Si from silicon substrate and Cd took place.
基金This work was supported by the National Natural Science Foundation of China (51973157,61904123)the Tianjin Natural Science Foundation (18JCQNJC02900)+3 种基金the Special Grade of the Financial Support from the China Postdoctoral Science Foundation (2020T130469)the Sci-ence and Technology Plans of Tianjin (19PTSYJC00010)the Science&Technol-ogy Development Fund of Tianjin Education Commission for Higher Education (2018KJ196)State Key Laboratory of Membrane and Membrane Separation,Tiangong University.
文摘Low-cost and flexible solid polymer electrolytes are promising in all-solid-state Li-metal batteries with high energy density and safety.However,both the low room-temperature ionic conductivities and the small Li^(+)transference number of these electrolytes significantly increase the internal resistance and overpotential of the battery.Here,we introduce Gd-doped CeO_(2) nanowires with large surface area and rich surface oxygen vacancies to the polymer electrolyte to increase the interaction between Gd-doped CeO_(2) nanowires and polymer electrolytes,which promotes the Li-salt dissociation and increases the concentration of mobile Li ions in the composite polymer electrolytes.The optimized composite polymer electrolyte has a high Li-ion conductivity of 5×10^(-4)4 S cm^(-1) at 30℃ and a large Li+transference number of 0.47.Moreover,the composite polymer electrolytes have excellent compatibility with the metallic lithium anode and high-voltage LiNi_(0.8)Mn _(0.1)Co_(0.1)O_(2)(NMC)cathode,providing the stable cycling of all-solid-state batteries at high current densities.
基金This study was financially supported by the National Natural Science Foundation of China(No.52072106)the Science and Technology Major Project of Anhui Province(No.202003a05020007)+2 种基金111 Project“New Materials and Technology for Clean Energy”(No.B18018)Fundamental Research Funds for the Central Universities of China(Nos.JZ2019HGBZ0134 and PA2019GDZC0096)the Enterprise Entrusted Project(No.W2021JSKF0868).
文摘Spinel MnCo_(2)O_(4) is a promising energy storage candidate as anode materials in lithium-ion batteries owing to synergistic effects of two intrinsic solid-state redox couples.However,low conductivity,poor rate capacity and rapid capacity fading have seriously impaired its practical applications.To overcome the inferiorities,urchin-like MnCo_(2)O_(4)@C core–shell nanowire arrays have been fabricated directly within a porous copper current collector via a facile hydrothermal method followed by a chemical vapor deposition carbonization process.In a typical nanowire,the core is composed of interconnected MnCo_(2)O_(4)nanoparticles and the shell shows as a thin amorphous carbon layer.The integrated MnCo_(2)O_(4)@C/Cu structure could act as working anodes without using additives or polymer binders.While MnCo_(2)O_(4)@C/Cu possesses slightly longer Li-ion insertion/desertion pathway than that of MnCo_(2)O_(4)/Cu,the carbon shell could effectively prevent the pulverization of MnCo_(2)O_(4) and lower down charge transfer resistance and actively participate in Li-ion cycles.The rearrangement of carbon atoms during lithiation/delithiation cycling could inhibit the formation of passive solid electrolyte interphase films.As a result,the MnCo_(2)O_(4)@C/Cu electrode presents superior rate capacity(600 mAh·g^(−1) at 1 A·g^(−1)) and better stability(797 mAh·g^(−1) after 200 cycles at 100 mA·g^(−1)).The excellent reversible Li ion storage capacity,cycling stability and rate capacity endow MnCo_(2)O_(4)@C/Cu great potential as stable and high output integrated anode materials in Li-ion batteries.
基金This work was supported by the National Natural Science Foundation of China (No. 51102134), the Natural Science Foundation of Jiangsu Province (No. BK20131349), the China Postdoctoral Science Foundation (No. 2013M530258), and the Jiangsu Planned Projects for Postdoctoral Research Funds (No. 1202001B).
文摘This paper reports a simple yet efficient method for the synthesis of hierarchical TiO2-B nanowire@α-Fe2O3 nanothorn core-branch arrays based on a stepwise hydrothermal approach. The as-fabricated hybrid arrays show impressive performance as a high-capacity anode for lithium-ion batteries. The key design in this study is a core-branch hybrid architecture, which not only provides large surface active sites for lithium ion insertion/extraction, but also enables fast charge transport owing to the reduced diffusion paths for both electrons and lithium ions. The peculiar combination of attributes of TiO2 (good structural stability) and Fe2O3 (large specific capacity) provides the hybrid array electrodes with several desirable electrochemical features: large reversible capacity (-800 mA.h.g^-1 for specific mass capacity and -750 μA.h-cm^-2 for specific areal" capacity), good cycling stability, and high rate capability. The impressive electrochemical performance, together with the facile synthesis procedure, may provide an efficient platform to integrate the TiO2 nanowire@Fe2O3 nanothorn core-branch arrays as a three-dimensional thin film electrode for lithium-ion microbatteries.
基金supported by the National Natural Science Foundation of China (Grant No.50772006)
文摘Highly ordered Cu2O coated silicon nanowire arrays (SiNWAs) were fabricated as photocatalyst via depositing Cu nanoparticles on silver-assisted electroless-etched SiNWAs and subsequently annealing. The as-prepared samples have been characterized by scanning electron microscopy, X-ray diffraction and UV-VIS-NIR spectrophotometry. The photocatalytic properties of the Cu2O coated SiNWAs were investigated by degradation of Rhodamine B (RhB) under simulated solar light with a cut-off filter (λ 〉 420 nm). The results indicated that H2O2 could greatly improve the photocatalytic properties of Cu2O coated SiNWAs, and exhibited strong synergy effect between them. The hybrid nanowire arrays will be promising photocatalytic materials in the field of energy and environment.
基金financially supported by the National Natural Science Foundation of China (Nos. 51232006, 51472218 and 11474249)the National Basic Research Program of China (No. 2015CB654900)
文摘Vertically aligned TiO2/SrTiO3 core–shell heterostructured nanowire arrays with different shell thicknesses(5–40 nm)were fabricated on fluorine-doped tin oxide substrate via a hydrothermal process.Microstructural characterization demonstrated that the TiO2 nanowires were uniformly coated by the singlecrystal SrTiO3 shell,where continuous and large-area interface could be clearly observed.By this means,significantly enhanced photoelectrochemical water splitting properties(0.78 mA·cm^-2 at 1.23 V vs.RHE)were successfully realized in well-designed sample(with a shell thickness of 5–10 nm)compared with those of pristine TiO2(0.38 mA·cm^-2 at 1.23 V vs.RHE).The improvement of photoelectrochemical properties was attributed to the improved charge injection and charge separation,which are calculated by the results of water oxidation and sulfite oxidation measurements.Based on these results,a mechanism was proposed that SrTiO3 shell acted as an electron–hole separation layer to improve the photocurrent density.On the other hand,the sample with an over-thick SrTiO3 shell(20–40 nm)exhibited slightly reduced photoelectrochemical properties(0.66 mA·cm^-2),which could be explained by the increase of the recombination rate in thethicker SrTiO3 shell.This work provided a facile strategy to improve and modulate the photoelectrochemical performance of heterostructured photoanodes.
基金supported by the National Natural Science Foundation of China (51571072)the Fundamental Research Funds for the Central Universities (AUGA5710012715)+1 种基金China Postdoctoral Science Foundation (2015M81436)Heilongjiang Postdoctoral Science Foundation (LBH-Z15065)
文摘In this paper, hierarchical mesoporous Co3O4@ZnCo2O4 hybrid nanowire arrays(NWAs) on Ni foam were prepared through a two-step hydrothermal process associated with successive annealing treatment. The Co3O4@ZnCo2O4 hybrid NWAs exhibited excellent electrochemical performances with a high specific capacity of 1,240.5 C g^-1 at a current density of 2 mA cm^-2, with rate capability of 59.0%shifting from 2 to 30 mA cm^-2, and only a 9.1% loss of its capacity even after 3,000 cycles at a consistent current density of 10 mA cm^-2. An asymmetric supercapacitor(Co3O4@ZnCo2O4 NWAs||activated carbon) was fabricated and exhibited a high specific capacity of 168 C g^-1 at a current density of 1 A g^-1. And a preferable energy density of 37.3 W h kg^-1 at a power density of 800 W kg^-1 was obtained. The excellent electrochemical performances indicate the promising potential application of the hierarchical mesoporous Co3O4@ZnCo2O4 hybrid NWAs in energy storage field.
基金supported by the National Natural Science Foundation of China(No.22072015)the Foundation of Sichuan Department of Science and Technology(No.2017FZ0079).
文摘The advancement of cost-effective and selective electrocatalyst towards CO_(2) to CO conversion is crucial for renewable energy conversion and storage,thus to achieve carbon-neutral cycle in a sustainable manner.In this communication,we report that CujSb decorated Cu nanowire arrays on Cu foil act as a highly active and selective electrocatalyst for CO_(2) to CO conversion.In CO_(2)-saturated 0.1 M KHCO_(3),it achieves a high Faraday efficiency(FE)of 86.5%for CO,at-0.90 V vs.reversible hydrogen electrode(RHE).The H_(2)/CO ratio is tunable from 0.08:1 to 5.9:1 by adjusting the potential.It is worth noting that HCOO-product was totally suppressed on such catalyst,compared with Sb counterpart.The improving selectivity for CO could be attributed to the bimetallic effect and nanowire arrays structure.
基金supported by the Ministry of Science and Technology of the People’s Republic of China (2017YFA0206704, 2016YFB0100103)the National Basic Research Program of China (2014CB932300)+3 种基金Strategic Priority Research Program of the Chinese Academy of Sciences (XDA09010404)Technology and Industry for National Defence of the People’s Republic of China (JCKY2016130B010)the National Natural Science Foundation of China (51771177, 21422108, 51472232)Jilin Province Science and Technology Development Program (20160101289JC)
文摘The successful development of Li-O_2 battery technology depends on developing a stable and efficient cathode. As an important step toward this goal, for the first time, we report the development of CeO_2 nanoparticles modified NiCo_2O_4 nanowire arrays(NWAs) grown on the carbon textiles as a new carbon-free and binder-free cathode system. In this study, the Li-O_2 battery with the CeO_2@NiCo_2O_4 NWAs has exhibited much reduced overpotentials, a high discharge capacity, an improved cycling stability,outperforming the Li-O_2 battery with NiCo_2O_4 NWAs. These improvements can be attributed to both the tailored morphology of discharge product and improved oxygen reduction reaction(ORR) and oxygen evolution reaction(OER) activity after CeO_2 NPs deposition. To a considerable extent, this idea of cathode construction including structure design and composition optimization can provide guidance for further researches in developing more powerful cathode for Li-O_2 battery.
基金supported by the Institute of Science and High Technology and Environmental Sciences(No.1/1859)
文摘TiO2 nanowire arrays were successfully fabricated by liquid-phase deposition method using porous alumina templates. The obtained TiO2 nanowires were characterized using Raman spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), field emission scanning electron microscopy (FE- SEM), transmission electron microscopy (TEM), and selected area electron diffraction (SAED) analysis. Results of electron microscopic observations indicated that the nanowires were smooth and uniform with a diameter of about 50-80 nm and several micrometers in length. SAED, Raman, and XRD mea- surements showed that TiO2 nanowires were single-crystalline with a pure rutile structure after heating at 800 ~C for 10 h. In this situation, the nanowire constituents grew preferentially along the 〈001〉 direction. Furthermore, the formation process and mechanistic study of the Ti02 nanowire arrays were proposed and discussed in detail. The nanowires are clearly produced by the deposition of TiO2 particles on the inner wall of the template nanochannels.
基金supported by the National Natural Science Foundation of China(No.51872254)the Outstanding Youth Foundation of Jiangsu Province of China(No.BK20211548)the Excellent Doctoral Dissertation Fund of Yangzhou University(2022).
文摘It is a huge challenge for metal oxide semiconductor gas sensors to inspect volatile organic compounds(VOCs)at room temperature(RT).Herein,the effective utilization of cerium oxide(CeO_(2))nanowires for RT detection of VOCs was realized via regulating its surface chemical state.Oxygen vacancy engineering on CeO_(2) nanowires,synthesized via hydrothermal method,can be manipulated by annealing under various controlled atmospheres.The sample annealed under 5%H_(2)+95%Ar condition exhibited outstanding RT sensing properties,displaying a high response of 16.7 towards 20 ppm linalool,a fast response and recovery time(16 and 121 s,respectively),and a low detection of limit of 0.54 ppm.The enhanced sensing performance could be ascribed for the synergistic effects of its nanowire morphology,the large specific surface area(83.95 m^(2)/g),and the formation of extensive oxygen vacancy accompanied by an increase in Ce^(3+).Additionally,the practicability of the sensor was verified via two varieties of rice(Indica and Japonica rice)stored in various periods(1,3,5,7,15,and 30 d).The experimental results revealed that the sensor was able to distinguish Indica rice from Japonica rice.Accordingly,the as-developed sensor delivers a strategic material to develop high-performance RT electronic nose equipment for monitoring rice quality.