We present a comparison of Mo, V and Nb oxides as shell materials atop haematite cores used for selective methanol oxidation. While Mo and V both yield high selectivity to formaldehyde, Nb does not. Very different rea...We present a comparison of Mo, V and Nb oxides as shell materials atop haematite cores used for selective methanol oxidation. While Mo and V both yield high selectivity to formaldehyde, Nb does not. Very different reactivity patterns are seen for Nb, which mainly shows dehydrogenation (to CO) and dehydration (to DME), indicating the lack of a complete shell, while Raman spectroscopy shows that the Mo and V formation process is not followed by NbOx. We suggest this is due to the large differences in mobility within the solid materials during formation, NbOx requiring significantly higher (and deleterious) calcination temperatures to allow sufficient mobility for shell completion.展开更多
Electrocatalytic nitrate reduction to ammonia(NO3−RR)for removing nitrate from wastewater is a promising but challengeable technology that is increasingly studied.Herein,we developed an efficient CuO_(x)and CoCuO_(x)c...Electrocatalytic nitrate reduction to ammonia(NO3−RR)for removing nitrate from wastewater is a promising but challengeable technology that is increasingly studied.Herein,we developed an efficient CuO_(x)and CoCuO_(x)composed hybrid catalyst(CoCuO_(x)@CuO_(x)/copper foam(CF)),characteristic of distinctive shell-core nanowires grown on CF substrate with CuO_(x)core and CoCuO_(x)shell.The built-in electric field formed at the interface of the CoO/Cu_(2)O heterostructure promotes NO3−adsorption by modulating the charge distribution at the interface,which greatly improves the ammonia yield rate and Faradaic efficiency.At−0.2 V vs.reversible hydrogen electrode(RHE),CoCuO_(x)@CuO_(x)/CF achieves not only an excellent ammonia yield rate of up to 519.1μg·h^(−1)·cm^(−2)and Faradaic efficiency of 99.83%at 1 mM NO3−concentration,but also excellent mechanical stabilities.This study provides a novel pathway to design electrocatalyst for the removal of nitrate from dilute nitric acid solutions(≤2 mM).展开更多
Spiral fibers with high energy storage and high output efficiency are highly desirable for soft robots and actuators.However,it is still a great challenge to achieve spiral fibers with excellent water actuation perfor...Spiral fibers with high energy storage and high output efficiency are highly desirable for soft robots and actuators.However,it is still a great challenge to achieve spiral fibers with excellent water actuation performance,structural stability,and high scalability in a low-cost strategy.A coaxial spiral structure is reported for the fabrication of high-performance fiber actuators.The developed shell-core helical fiber actuators were based on alginate/poly(ethylene glycol)acrylate shell and alginate/GO core with green and excellent spinnability.Owing to the high water-absorbing-swelling capacity and energy storage of the shell,the prepared spiral fibers are characterized by fast response,high energy output,and good repeatability of cycling.On the other hand,the core endows the spiral fibers with the additional features of strong force retention and photothermal response.The shell-core spiral structure promotes the output efficiency of the twisted fiber actuator with a large rotation(2500°/cm),untwisting speed(2250 rpm),and recovery speed(2700 rpm).In addition,the tertiary spiral structure based on TAPG fibers exhibits excellent humidity and photothermal response efficiency.The application of fibers to smart textiles enables efficient human epidermal thermal management.展开更多
Using SnSO4,D-glucose,urea and water,hierarchical shell-core SnO2 microspheres were successfully synthesized via a simple hydrothermal method.The characte rization results showed that the sizes of asprepared SnO2 micr...Using SnSO4,D-glucose,urea and water,hierarchical shell-core SnO2 microspheres were successfully synthesized via a simple hydrothermal method.The characte rization results showed that the sizes of asprepared SnO2 microspheres were 0,6-1μm,with shell thicknesses of 4060 nm,The shell and large core of the SnO2 microspheres were all comprised of the same basic rice-like nanoparticles with diameters of 16-25 nm and lengths of 16-45 nm.Further investigaton showed that the glucose and urea served as structural guiding agents,and urea facilitated the formation of the hierarchical structure.The as-prepared SnO2 nanomaterials were used to fabricate a gas sensor with an electrode blade used for the gas sensitivity tests,The hierarchical shell-core SnO2 microspheres exhibited high sensitivity and selectivity toward ethanol,with a responsivity of 63.8 for 50 ppm ethanol at 250℃,while the response and recovery time were 7 s and 28 s,respectively.Moreover,the responsivity of the materials showed good linearity at ethanol concentrations from 500 ppb to 10 ppm.The simple synthetic method,environmentally-friendly raw materials,and excellent gas sensitivity demonstrate that the as-prepared SnO2 nanomaterial has great potential applications for the sensing of ethanol gas.展开更多
The synthesis of carbon supporter/nanoscale high-entropy alloys(HEAs)electromagnetic response composites by carbothermal shock method has been identified as an advanced strategy for the collaborative competition engin...The synthesis of carbon supporter/nanoscale high-entropy alloys(HEAs)electromagnetic response composites by carbothermal shock method has been identified as an advanced strategy for the collaborative competition engineering of conductive/dielectric genes.Electron migration modes within HEAs as manipulated by the electronegativity,valence electron configurations and molar proportions of constituent elements determine the steady state and efficiency of equivalent dipoles.Herein,enlightened by skin-like effect,a reformative carbothermal shock method using carbonized cellulose paper(CCP)as carbon supporter is used to preserve the oxygencontaining functional groups(O·)of carbonized cellulose fibers(CCF).Nucleation of HEAs and construction of emblematic shell-core CCF/HEAs heterointerfaces are inextricably linked to carbon metabolism induced by O·.Meanwhile,the electron migration mode of switchable electronrich sites promotes the orientation polarization of anisotropic equivalent dipoles.By virtue of the reinforcement strategy,CCP/HEAs composite prepared by 35%molar ratio of Mn element(CCP/HEAs-Mn_(2.15))achieves efficient electromagnetic wave(EMW)absorption of−51.35 dB at an ultra-thin thickness of 1.03 mm.The mechanisms of the resulting dielectric properties of HEAs-based EMW absorbing materials are elucidated by combining theoretical calculations with experimental characterizations,which provide theoretical bases and feasible strategies for the simulation and practical application of electromagnetic functional devices(e.g.,ultra-wideband bandpass filter).展开更多
基金EPSRC for support via the UK Catalysis Hub(EP/K014854/1,EP/K014714/1)EPSRC and Diamond Light Source for funding the studentship to PH
文摘We present a comparison of Mo, V and Nb oxides as shell materials atop haematite cores used for selective methanol oxidation. While Mo and V both yield high selectivity to formaldehyde, Nb does not. Very different reactivity patterns are seen for Nb, which mainly shows dehydrogenation (to CO) and dehydration (to DME), indicating the lack of a complete shell, while Raman spectroscopy shows that the Mo and V formation process is not followed by NbOx. We suggest this is due to the large differences in mobility within the solid materials during formation, NbOx requiring significantly higher (and deleterious) calcination temperatures to allow sufficient mobility for shell completion.
基金the National Natural Science Foundation of China(No.22204119)Science and Technology Plans of Tianjin(No.22ZYJDSS00070).
文摘Electrocatalytic nitrate reduction to ammonia(NO3−RR)for removing nitrate from wastewater is a promising but challengeable technology that is increasingly studied.Herein,we developed an efficient CuO_(x)and CoCuO_(x)composed hybrid catalyst(CoCuO_(x)@CuO_(x)/copper foam(CF)),characteristic of distinctive shell-core nanowires grown on CF substrate with CuO_(x)core and CoCuO_(x)shell.The built-in electric field formed at the interface of the CoO/Cu_(2)O heterostructure promotes NO3−adsorption by modulating the charge distribution at the interface,which greatly improves the ammonia yield rate and Faradaic efficiency.At−0.2 V vs.reversible hydrogen electrode(RHE),CoCuO_(x)@CuO_(x)/CF achieves not only an excellent ammonia yield rate of up to 519.1μg·h^(−1)·cm^(−2)and Faradaic efficiency of 99.83%at 1 mM NO3−concentration,but also excellent mechanical stabilities.This study provides a novel pathway to design electrocatalyst for the removal of nitrate from dilute nitric acid solutions(≤2 mM).
基金the financial support provided by the Fundamental Research Funds for the Central Universities(No.2232023G-04)Shanghai Frontiers Science Center of Advanced Textiles,Donghua University,Shanghai,China.
文摘Spiral fibers with high energy storage and high output efficiency are highly desirable for soft robots and actuators.However,it is still a great challenge to achieve spiral fibers with excellent water actuation performance,structural stability,and high scalability in a low-cost strategy.A coaxial spiral structure is reported for the fabrication of high-performance fiber actuators.The developed shell-core helical fiber actuators were based on alginate/poly(ethylene glycol)acrylate shell and alginate/GO core with green and excellent spinnability.Owing to the high water-absorbing-swelling capacity and energy storage of the shell,the prepared spiral fibers are characterized by fast response,high energy output,and good repeatability of cycling.On the other hand,the core endows the spiral fibers with the additional features of strong force retention and photothermal response.The shell-core spiral structure promotes the output efficiency of the twisted fiber actuator with a large rotation(2500°/cm),untwisting speed(2250 rpm),and recovery speed(2700 rpm).In addition,the tertiary spiral structure based on TAPG fibers exhibits excellent humidity and photothermal response efficiency.The application of fibers to smart textiles enables efficient human epidermal thermal management.
基金financially supported by the National Natural Science Foundation of China (No.21471120)。
文摘Using SnSO4,D-glucose,urea and water,hierarchical shell-core SnO2 microspheres were successfully synthesized via a simple hydrothermal method.The characte rization results showed that the sizes of asprepared SnO2 microspheres were 0,6-1μm,with shell thicknesses of 4060 nm,The shell and large core of the SnO2 microspheres were all comprised of the same basic rice-like nanoparticles with diameters of 16-25 nm and lengths of 16-45 nm.Further investigaton showed that the glucose and urea served as structural guiding agents,and urea facilitated the formation of the hierarchical structure.The as-prepared SnO2 nanomaterials were used to fabricate a gas sensor with an electrode blade used for the gas sensitivity tests,The hierarchical shell-core SnO2 microspheres exhibited high sensitivity and selectivity toward ethanol,with a responsivity of 63.8 for 50 ppm ethanol at 250℃,while the response and recovery time were 7 s and 28 s,respectively.Moreover,the responsivity of the materials showed good linearity at ethanol concentrations from 500 ppb to 10 ppm.The simple synthetic method,environmentally-friendly raw materials,and excellent gas sensitivity demonstrate that the as-prepared SnO2 nanomaterial has great potential applications for the sensing of ethanol gas.
基金Financial support from the National Natural Science Foundation of China(52372289,52102368,52231007,12327804,T2321003,22088101,22178037 and U22A20424)Regional Joint Fund for Basic Research and Applied Basic Research of Guangdong Province(No.2020A1515110905)+1 种基金Guangdong Special Fund for key Areas(20237DZX3042)Shenzhen Stable Support Project,Liaoning Revitalization Talents Program(XLYC2002114)are highly appreciated.
文摘The synthesis of carbon supporter/nanoscale high-entropy alloys(HEAs)electromagnetic response composites by carbothermal shock method has been identified as an advanced strategy for the collaborative competition engineering of conductive/dielectric genes.Electron migration modes within HEAs as manipulated by the electronegativity,valence electron configurations and molar proportions of constituent elements determine the steady state and efficiency of equivalent dipoles.Herein,enlightened by skin-like effect,a reformative carbothermal shock method using carbonized cellulose paper(CCP)as carbon supporter is used to preserve the oxygencontaining functional groups(O·)of carbonized cellulose fibers(CCF).Nucleation of HEAs and construction of emblematic shell-core CCF/HEAs heterointerfaces are inextricably linked to carbon metabolism induced by O·.Meanwhile,the electron migration mode of switchable electronrich sites promotes the orientation polarization of anisotropic equivalent dipoles.By virtue of the reinforcement strategy,CCP/HEAs composite prepared by 35%molar ratio of Mn element(CCP/HEAs-Mn_(2.15))achieves efficient electromagnetic wave(EMW)absorption of−51.35 dB at an ultra-thin thickness of 1.03 mm.The mechanisms of the resulting dielectric properties of HEAs-based EMW absorbing materials are elucidated by combining theoretical calculations with experimental characterizations,which provide theoretical bases and feasible strategies for the simulation and practical application of electromagnetic functional devices(e.g.,ultra-wideband bandpass filter).
