The graphene oxide powder(GOP)obtained from the spray drying process often exhibits poor redispersibility which is considered due to the partial reduction of GO sheets.The reduction of drying temperature can effective...The graphene oxide powder(GOP)obtained from the spray drying process often exhibits poor redispersibility which is considered due to the partial reduction of GO sheets.The reduction of drying temperature can effectively increase the redispersibility of GOP,but result in a decreased drying efficiency.Herein,we found that the redispersibility of GOP is strongly affected by its microstructure,which is determined by the feed concentration.With the increase of feed concentration,the GO nanosheet assembly varies from the disordered stacking to relatively oriented assembly,making the morphology of the GOP transform from balllike(the most crumpled one)to flakelike(the least crumpled one),and the 0.8 mgml 1 is the threshold concentration for the morphology,structure,and redispersibility change.Once the feed concentration reaches 0.8 mg ml 1,the appearance of the nematic phase in droplet ensures the relatively oriented assembly of GO sheets to form the layered structure with a low crumpling degree,which greatly improves the polar parts surface tension of the solid GOP,making the GOP easier to form hydrogen bonding with water during the redispersion process,thus stabilizing dispersion.This work provides useful information for understanding the relationships between the morphology,microstructure,and final redispersibility of GOPs.展开更多
High-entropy materials(HEMs)have attracted extensive attention in the field of electrochemical catal-ysis due to their unique properties.However,the preparation of high-entropy catalysts typically relies on high-tempe...High-entropy materials(HEMs)have attracted extensive attention in the field of electrochemical catal-ysis due to their unique properties.However,the preparation of high-entropy catalysts typically relies on high-temperature,energy-intensive,and time-consuming synthesis methods due to their compositional complexity.In this study,a facile low-temperature electrochemical reconstruction approach is adopted to synthesize Ag-decorated septenary Co-Cu-Fe-Mo-Zn-Ag-Ru high-entropy(oxy)hydroxide electro-catalysts for oxygen evolution reaction(OER).By introducing Ag and Ru elements and implanting Ag nanoparticles to co-regulate the electronic structure of the catalysts,the as-prepared catalyst achieves remarkable OER performance with a low overpotential of 298 mV at 100 mA/cm^(2)and a small Tafel slope of 30.1 mV/dec in 1 mol/L KOH.This work offers a valuable strategy for developing high-performance high-entropy OER electrocatalysts.展开更多
High-performance fiber-shaped power sources are anticipated to considerably contribute to the continuous development of smart wearable devices.As one-/two-dimensional(1D/2D)frameworks constructed from graphene sheets,...High-performance fiber-shaped power sources are anticipated to considerably contribute to the continuous development of smart wearable devices.As one-/two-dimensional(1D/2D)frameworks constructed from graphene sheets,graphene fibers and fabrics inherit the merits of graphene,including its lightweight nature,high electrical conductivity,and exceptional mechanical strength.The as-fabricated graphene fiber/fabric flexible supercapacitor(FSC)is,therefore,regarded as a promis-ing candidate for next-generation wearable energy storage devices owing to its high energy/power density,adequate safety,satisfactory flexibility,and extended cycle life.The gap between practical applications and experimental demonstrations of FSC is drastically reduced as a result of technological advancements.To this end,herein,recent advancements of FSCs in fiber element regulation,fiber/fabric construction,and practical applications are methodically reviewed and a forecast of their growth is presented.展开更多
Ti_(3)C_(2)T_(x)MXene fiber has shown extraordinary potential for supercapacitor electrode in wearable elec-tronics and textile energy storage,but realizing high energy density and practical-powered applications remai...Ti_(3)C_(2)T_(x)MXene fiber has shown extraordinary potential for supercapacitor electrode in wearable elec-tronics and textile energy storage,but realizing high energy density and practical-powered applications remains a great challenge.Here,we report a covalent-architected molybdenum disulfide-Ti_(3)C_(2)T_(x)(MoS_(2)-Ti_(3)C_(2)T_(x))core-shell fiber for high-performance supercapacitor.Benefiting from the microfluidic and micro-reaction strategies,the ordered MoS_(2)arrays are strongly bridged on Ti_(3)C_(2)T_(x)fiber via Ti-O-Mo bond,re-sulting in large exposed surface,enhanced porosity and excellent interfacial conduction for charges high diffusion and faradaic transfer.The MoS_(2)-Ti_(3)C_(2)T_(x)fiber exhibits ultra-large capacitance of 2028 F cm^(-3)and admirable reversibility in 1 M H_(2)SO_(4)aqueous electrolyte.Meanwhile,MoS_(2)-Ti_(3)C_(2)T_(x)fiber-based solid-state supercapacitor presents high energy density of 23.86 mWh cm^(-3),capacitance of 1073.6 F cm^(-3)and superior cycling ability of 92.13%retention after 20,000 cycles,which can realize stable energy supply for wearable watch,LEDs,electric fans,toy ship and self-powered devices.Our work may provide an insight-ful guidance for the advanced design of structural fiber towards robust new energy and next-generation wearable industry.展开更多
An ordered hollow M0S2 nanocages/RGO nanocomposite is constructed by a simple solvothermal-assisted assembly method combined with freeze-drying and annealing.In this novel nanostructure,hollow M0S2 nanocages are homog...An ordered hollow M0S2 nanocages/RGO nanocomposite is constructed by a simple solvothermal-assisted assembly method combined with freeze-drying and annealing.In this novel nanostructure,hollow M0S2 nanocages are homogeneously distributed on graphene sheets with a tight bond of C-O-Mo.The nanosized and hollow MoS2 nanocages can effectively accommodate the huge volume change during charge/discharge process and increase the number of electrochemical reaction active sites,accelerating the kinetics of lithiation/delithiation.The tight C-O-Mo bond between graphene and MoS2 further reinforces the structural stability,thus improve the electrical conductivity and substantially enhance the lithium storage performance of M0S2 anode material.As a result,this novel nanocomposite shows a long-cycle stability of 717.4 mAh·g^-1 after 800 cycles at a high current density of 3 A·g^-1,exhibiting great potential as an anode nanocomposite for advanced lithium-ion batteries.展开更多
（Ce_（0.04）Y_（2.96））Al_5O_（12） phosphor nanoparticles were prepared by a modified co-precipitation method with graphene oxide（GO） nanosheets used as dispersing agent. The GO concentration is controlled at 0.0...（Ce_（0.04）Y_（2.96））Al_5O_（12） phosphor nanoparticles were prepared by a modified co-precipitation method with graphene oxide（GO） nanosheets used as dispersing agent. The GO concentration is controlled at 0.0.005,0.01, 0.02, and 0.03 g/L. The addition of lamellar GO nanosheets in the precipitant solution possibly enhances both the dispersity of precursor particles and the crystallinity of phosphor nanoparticles. Pure Ce-doped YAG phase is obtained by calcining the precipitate at 1000 ℃ for 3 h. The（Ce_（0.04）Y_（2.96））Al_5 O_（12）phosphor nanoparticles have an average size of 64 nm and there is no significant change on particle size with increase of the GO concentration in precipitant solution. The luminescence property of（Ce_（0.04）Y_（2.96））Al_5O_（12） phosphor nanoparticles varies with different concentrations of GO. The photoluminescence emission intensity of the optimum sample with 0.02 g/L GO is about 1.6 times higher than the sample without using GO.展开更多
基金the National Key R&D Program of China(2019YFD1101200,2019YFD1101204)Natural Science Foundation of China(51772150)the Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)Jiangsu Provincial Key Research and Development Program(BE2018008-1).
文摘The graphene oxide powder(GOP)obtained from the spray drying process often exhibits poor redispersibility which is considered due to the partial reduction of GO sheets.The reduction of drying temperature can effectively increase the redispersibility of GOP,but result in a decreased drying efficiency.Herein,we found that the redispersibility of GOP is strongly affected by its microstructure,which is determined by the feed concentration.With the increase of feed concentration,the GO nanosheet assembly varies from the disordered stacking to relatively oriented assembly,making the morphology of the GOP transform from balllike(the most crumpled one)to flakelike(the least crumpled one),and the 0.8 mgml 1 is the threshold concentration for the morphology,structure,and redispersibility change.Once the feed concentration reaches 0.8 mg ml 1,the appearance of the nematic phase in droplet ensures the relatively oriented assembly of GO sheets to form the layered structure with a low crumpling degree,which greatly improves the polar parts surface tension of the solid GOP,making the GOP easier to form hydrogen bonding with water during the redispersion process,thus stabilizing dispersion.This work provides useful information for understanding the relationships between the morphology,microstructure,and final redispersibility of GOPs.
基金supported by the National Key Research and Development Program of China[grant number 2020YFE0100100]the National Natural Science Foundation of China[grant number 52222103]the Fundamental Research Funds for the Central Universities and the Key Research and Development Program of Sichuan Province(Scientific and Technological Cooperation of Sichuan Province with Institutes and Universities)[grant number 2020YFSY0001].
文摘High-entropy materials(HEMs)have attracted extensive attention in the field of electrochemical catal-ysis due to their unique properties.However,the preparation of high-entropy catalysts typically relies on high-temperature,energy-intensive,and time-consuming synthesis methods due to their compositional complexity.In this study,a facile low-temperature electrochemical reconstruction approach is adopted to synthesize Ag-decorated septenary Co-Cu-Fe-Mo-Zn-Ag-Ru high-entropy(oxy)hydroxide electro-catalysts for oxygen evolution reaction(OER).By introducing Ag and Ru elements and implanting Ag nanoparticles to co-regulate the electronic structure of the catalysts,the as-prepared catalyst achieves remarkable OER performance with a low overpotential of 298 mV at 100 mA/cm^(2)and a small Tafel slope of 30.1 mV/dec in 1 mol/L KOH.This work offers a valuable strategy for developing high-performance high-entropy OER electrocatalysts.
基金supported by the Natural Science Foundation of China(No.51425202,No.51772150)the Natural Science Foundation of Jiangsu Province(No.BK20211592,No.BK20160093)+1 种基金the Key Research and Development Program of Jiangsu Province(No.BE2016006-1)the Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD).
文摘High-performance fiber-shaped power sources are anticipated to considerably contribute to the continuous development of smart wearable devices.As one-/two-dimensional(1D/2D)frameworks constructed from graphene sheets,graphene fibers and fabrics inherit the merits of graphene,including its lightweight nature,high electrical conductivity,and exceptional mechanical strength.The as-fabricated graphene fiber/fabric flexible supercapacitor(FSC)is,therefore,regarded as a promis-ing candidate for next-generation wearable energy storage devices owing to its high energy/power density,adequate safety,satisfactory flexibility,and extended cycle life.The gap between practical applications and experimental demonstrations of FSC is drastically reduced as a result of technological advancements.To this end,herein,recent advancements of FSCs in fiber element regulation,fiber/fabric construction,and practical applications are methodically reviewed and a forecast of their growth is presented.
基金This work was financially supported by the National Natu-ral Science Foundation of China(Nos.22278378,22208190,and 21706120)the Natural Science Foundation of Jiangsu Province(No.BK20211592)+2 种基金the National Postdoctoral Program for Innovative Tal-ents(No.BX2021146)the Shuimu Tsinghua Scholar Program(No.2021SM055)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD).
文摘Ti_(3)C_(2)T_(x)MXene fiber has shown extraordinary potential for supercapacitor electrode in wearable elec-tronics and textile energy storage,but realizing high energy density and practical-powered applications remains a great challenge.Here,we report a covalent-architected molybdenum disulfide-Ti_(3)C_(2)T_(x)(MoS_(2)-Ti_(3)C_(2)T_(x))core-shell fiber for high-performance supercapacitor.Benefiting from the microfluidic and micro-reaction strategies,the ordered MoS_(2)arrays are strongly bridged on Ti_(3)C_(2)T_(x)fiber via Ti-O-Mo bond,re-sulting in large exposed surface,enhanced porosity and excellent interfacial conduction for charges high diffusion and faradaic transfer.The MoS_(2)-Ti_(3)C_(2)T_(x)fiber exhibits ultra-large capacitance of 2028 F cm^(-3)and admirable reversibility in 1 M H_(2)SO_(4)aqueous electrolyte.Meanwhile,MoS_(2)-Ti_(3)C_(2)T_(x)fiber-based solid-state supercapacitor presents high energy density of 23.86 mWh cm^(-3),capacitance of 1073.6 F cm^(-3)and superior cycling ability of 92.13%retention after 20,000 cycles,which can realize stable energy supply for wearable watch,LEDs,electric fans,toy ship and self-powered devices.Our work may provide an insight-ful guidance for the advanced design of structural fiber towards robust new energy and next-generation wearable industry.
基金This research was supported by the National Natural Science Foundation of China(No.51772150,21808103)Natural Science Foundation of Jiangsu Province(No.BK20171012)the Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD).The authors are grateful to Dr.Lin Gao and the Reviewers for their helpful suggestions and comments.
文摘An ordered hollow M0S2 nanocages/RGO nanocomposite is constructed by a simple solvothermal-assisted assembly method combined with freeze-drying and annealing.In this novel nanostructure,hollow M0S2 nanocages are homogeneously distributed on graphene sheets with a tight bond of C-O-Mo.The nanosized and hollow MoS2 nanocages can effectively accommodate the huge volume change during charge/discharge process and increase the number of electrochemical reaction active sites,accelerating the kinetics of lithiation/delithiation.The tight C-O-Mo bond between graphene and MoS2 further reinforces the structural stability,thus improve the electrical conductivity and substantially enhance the lithium storage performance of M0S2 anode material.As a result,this novel nanocomposite shows a long-cycle stability of 717.4 mAh·g^-1 after 800 cycles at a high current density of 3 A·g^-1,exhibiting great potential as an anode nanocomposite for advanced lithium-ion batteries.
基金Project supported by the Natural Science Foundation of Jiangsu Province(BK20160093)the Natural Science Foundation of China(51425202)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)
文摘（Ce_（0.04）Y_（2.96））Al_5O_（12） phosphor nanoparticles were prepared by a modified co-precipitation method with graphene oxide（GO） nanosheets used as dispersing agent. The GO concentration is controlled at 0.0.005,0.01, 0.02, and 0.03 g/L. The addition of lamellar GO nanosheets in the precipitant solution possibly enhances both the dispersity of precursor particles and the crystallinity of phosphor nanoparticles. Pure Ce-doped YAG phase is obtained by calcining the precipitate at 1000 ℃ for 3 h. The（Ce_（0.04）Y_（2.96））Al_5 O_（12）phosphor nanoparticles have an average size of 64 nm and there is no significant change on particle size with increase of the GO concentration in precipitant solution. The luminescence property of（Ce_（0.04）Y_（2.96））Al_5O_（12） phosphor nanoparticles varies with different concentrations of GO. The photoluminescence emission intensity of the optimum sample with 0.02 g/L GO is about 1.6 times higher than the sample without using GO.
