Renewable porous biochar and 2 D MXene have attracted significant attention in high-end electromagnetic interference(EMI)shielding fields,due to unique orderly structures and excellent electrical conductivity(r)value....Renewable porous biochar and 2 D MXene have attracted significant attention in high-end electromagnetic interference(EMI)shielding fields,due to unique orderly structures and excellent electrical conductivity(r)value.In this work,the wood-derived porous carbon(WPC)skeleton from natural wood was performed as a template.And excellent conductive and ultra-light 3D MXene aerogel was then constructed to prepare the MXene aerogel/WPC composites,based on highly ordered honeycomb cells inner WPC as a microreactor.Higher carbonization temperature is more conducive to the graphitization degree of natural wood.MXene aerogel/WPC composites achieve the optimal EMI SE value of up to 71.3 d B at density as low as 0.197 g/cm^3.Such wall-like"mortar-brick"structures(WPC skeleton as"mortar"and MXene aerogel as"brick")not only effectively solve the unstable structure problem of MXene aerogel networks,but also greatly prolong the transmission paths of the electromagnetic waves and dissipate the incident electromagnetic waves in the form of heat and electric energy,thereby exhibiting the superior EMI shielding performance.In addition,MXene aerogel/WPC composites also exhibit good anisotropic compressive strength,excellent thermal insulation and flame retardant properties.Such ultra-light,green and efficient multi-functional bio-carbon-based composites have great application potential in the high-end EMI shielding fields of aerospace and national defence industry,etc.展开更多
The development of functional composites with excellent thermal management capabilities and electro-magnetic interference(EMI)shielding has become extremely urgent for keeping up with the continuous improvement of the...The development of functional composites with excellent thermal management capabilities and electro-magnetic interference(EMI)shielding has become extremely urgent for keeping up with the continuous improvement of the operating speed and efficiency for electronic equipment.In this study,the biolog-ical wood-derived porous carbon(WPC)was determined as the supporting material to encapsulating polyethylene glycol(PEG),and a series of WPC/PEG/Fe_(3)O_(4) phase change composites(PCCs)with excel-lent shape stability,EMI shielding and thermal management capabilities were prepared via a simple vac-uum impregnation method.The Fe_(3)O_(4) magnetic particles modified PCCs have greatly improved the EMI shielding effectiveness(SE).The EMI SE of WP-4(7.5 wt.% Fe_(3)O_(4) in PEG)can be up to 55.08 dB between 8.2−12.4 GHz,however,the WP-0 without Fe_(3)O_(4) addition is only 40.08 dB.Meanwhile,the absorption ratio of electromagnetic waves(EMW)has also increased from 75.02%(WP-0)to 85.56%(WP-4),which effectively prevents secondary pollution.In addition,after wrapping a thin layer of polydimethylsiloxane resin(PDMS),the obtained WP-4 can maintain a high heat storage capacity(109.52 J/g)and good wa-ter stability.In short,the prepared WPC/PEG/Fe_(3)O_(4) PCCs have great potential application value in the thermal management and electromagnetic shielding requirements for electronic devices.展开更多
Expanding the application scenarios of wood-derived biochar guided by the conversion of traditional energy to new energy shows great promise as a field.As thrilling energy conversion apparatus,zinc-air batteries(ZABs)...Expanding the application scenarios of wood-derived biochar guided by the conversion of traditional energy to new energy shows great promise as a field.As thrilling energy conversion apparatus,zinc-air batteries(ZABs)require cathode catalysts with high oxygen reduction reaction(ORR)and oxygen evolution reaction(OER)activities and stability.Herein,two-dimensional nickel-iron hydroxide nanosheets were creatively assembled in N-doped wood-derived biochar(NiFe-LDH@NC)by an in-situ growth method.The categorized porous organization in wood-derived biochar facilitates the rapid seepage of electrolytes and rapid diffusion of reaction gases.The unique interfacial structure of biochar and NiFe-LDH accelerates electron transfer during oxygen electrocatalysis,and endows NiFe-LDH@NC with first-class catalytic activity and durability for ORR and OER.The ZAB derived from NiFe-LDH@NC showed elevated discharge productivity and cycle endurance,making it promising for viable applications.This work provided a convenient way for the conversion of wood-derived biochar to high-value added electrocatalysts.展开更多
Wood-derived carbon has a 3D porous framework composed of through channels along the growth direction,which is a suitable matrix for preparing electromagnetic wave(EMW)absorbing materials with low cost,light weight,an...Wood-derived carbon has a 3D porous framework composed of through channels along the growth direction,which is a suitable matrix for preparing electromagnetic wave(EMW)absorbing materials with low cost,light weight,and environmental friendliness.Herein,the carbonized wood decorated by short cone-like NiCo_(2)O_(4)(NiCo_(2)O_(4)@CW)with highly ordered straight-channel architecture was successfully manufactured through a facile calcination procedure.The horizontal arrangement of the through channels of NiCo_(2)O_(4)@CW(H-NiCo_(2)O_(4)@CW)exhibits a strong reflection loss value of-64.0 dB at 10.72 GHz with a thickness of 3.62 mm and a low filling ratio of 26 wt%(with the density of 0.98 g-cnf3),and the effective absorption bandwidth(EAB)is 8.08 GHz(9.92-18.0 GHz)at the thickness of 3.2 mm.The excellent microwave absorption(MA)property was ascribed to the ordered-channel structure with abundant interfaces and defects from NiCo_(2)O_(4)@CW,which could promote the interfacial polarization and dipole polarization.What is more,this advantageous structure increased the multiple reflections and scattering.Finite element analysis(FEA)simulation is carried out to detect the interaction between the prepared material and EMW when the ordered channels are arranged in different directions.This research provides a low-cost,sustainable,and environmentally friendly strategy for using carbonized wood to fabricate microwave absorbers with strong attenuation capabilities and light weight.展开更多
Wood-derived carbons have been demonstrated to have large specific capacities as the anode materials of lithium-ion batteries(LIBs). However, these carbons generally show low tap density and minor volumetric capacity ...Wood-derived carbons have been demonstrated to have large specific capacities as the anode materials of lithium-ion batteries(LIBs). However, these carbons generally show low tap density and minor volumetric capacity because of high specific surface area and pore volume. Combination with metal oxide is one of the expected methods to alleviate the obstacles of wood-derived carbons. In this work, the composites of Mn O loaded wood-derived carbon fibers(CF@Mn O) were prepared via a simple and environmentally friendly method, showing decreased specific surface area due to the generation of Mn O nanoparticles on carbon fibers. Furthermore, the CF@Mn O compostites exhibit superior electrochemical performance as anode materials of LIBs, which show high reversible capacity in the range of 529-734 m Ah/g at a current density of 100 m A/g. The optimal CF@Mn O product(Mn O:carbon = 1:2) delivers reversible capacity of 734 and 265.3 m Ah/g at current density of 100 and 2000 m A/g, respectively. Besides, the material presents outstanding stability with coulombic efficiency around 100% after 200 cycles at a high current density of 400 m A/g, revealing a potential as promising anode materials for high-performance LIBs.展开更多
The flow-through electro-Fenton(EF-T)reactor with WBC cathode was designed to remove florfenicol(FF).The activated WBC cathode was prepared by facile carbonization and activation methods,and featured high specific sur...The flow-through electro-Fenton(EF-T)reactor with WBC cathode was designed to remove florfenicol(FF).The activated WBC cathode was prepared by facile carbonization and activation methods,and featured high specific surface area,natural multi-channel structure,abundant oxygen-containing groups,good hydrophilicity,and excellent O_(2)reducing capacity.WBC cathode was located above Ti/Ru-IrO_(2)mesh anode.O_(2)evolved at the anode was carried to the inner wall of channel of WBC by the force of buoyancy and water flow,which increases oxygen source of H_(2)O_(2)generation at the cathode.The flow-through system by using WBC electrode promote the mass transfer of O_(2)and FF.The production amount of H_(2)O_(2)at activated WBC was 32.2 mg/L,which was almost twice as much as that at non-activated WBC(15.0 mg/L).FF removal ratio in EF-T system was 98%,which was much higher than that of traditional flow-by electro-Fenton(EF-B,33%)or single electrooxidation system(EO,16%).EF-T system has the lowest energy consumption(4.367 kWh/kg)among the three electrochemical systems.The cathodic adsorption,anodic electrooxidation,and EF reaction are responsible for the degradation of FF.After five consecutive cycle experiments,FF removal ratio was still 98%,indicating WBC has the good stability.展开更多
目的研究木浆源甾醇对高脂高胆固醇仓鼠肝脏中胆固醇代谢基因表达的影响。方法测定空白组、高脂组、实验组仓鼠的质量、脏器重量、血清中总胆固醇(total cholesterol,TC)、高密度脂蛋白胆固醇(high density lipoprotein cholesterol,HDL...目的研究木浆源甾醇对高脂高胆固醇仓鼠肝脏中胆固醇代谢基因表达的影响。方法测定空白组、高脂组、实验组仓鼠的质量、脏器重量、血清中总胆固醇(total cholesterol,TC)、高密度脂蛋白胆固醇(high density lipoprotein cholesterol,HDL-C)、甘油三酯(triglyceride,TG)水平。检测肝脏中胆固醇代谢相关调控基因m RNA表达水平及肝脏胆固醇含量和粪便固醇排泄量。结果木浆源甾醇可以极显著降低TC、TG、和Non HDL-C水平(P<0.01),同时极显著降低肝脏中胆固醇含量和肝脏重量(P<0.01),显著增加粪中固醇排泄量(P<0.05)。实验组肝脏中SREBP2、CYP7A1、HMG-Co A-R和LDL-R m RNA表达水平显著上调(P<0.05)。给予木浆源甾醇后可以改变肠道菌群多样性,增加有益菌减少有害菌数量。结论木浆源甾醇可能通过调控肝脏中胆固醇代谢相关基因的表达,抑制胆固醇的合成吸收并增加固醇的排泄,同时丰富肠道微生物多样性,增加有益菌数量,协同作用调控机体胆固醇的代谢。展开更多
基金supported by the Foundation of National Natural Science Foundation of China(51973173)Natural Science Basic Research Plan for Distinguished Young Scholars in Shaanxi Province of China(2019JC-11)+2 种基金Space Supporting Fund from China Aerospace Science and Industry Corporation(2019-HT-XG)Foundation of Aeronautics Science Fund(2017ZF53071)the School-enterprise Collaborative Innovation Fund for Graduate Students of Northwestern Polytechnical University(XQ201913)。
文摘Renewable porous biochar and 2 D MXene have attracted significant attention in high-end electromagnetic interference(EMI)shielding fields,due to unique orderly structures and excellent electrical conductivity(r)value.In this work,the wood-derived porous carbon(WPC)skeleton from natural wood was performed as a template.And excellent conductive and ultra-light 3D MXene aerogel was then constructed to prepare the MXene aerogel/WPC composites,based on highly ordered honeycomb cells inner WPC as a microreactor.Higher carbonization temperature is more conducive to the graphitization degree of natural wood.MXene aerogel/WPC composites achieve the optimal EMI SE value of up to 71.3 d B at density as low as 0.197 g/cm^3.Such wall-like"mortar-brick"structures(WPC skeleton as"mortar"and MXene aerogel as"brick")not only effectively solve the unstable structure problem of MXene aerogel networks,but also greatly prolong the transmission paths of the electromagnetic waves and dissipate the incident electromagnetic waves in the form of heat and electric energy,thereby exhibiting the superior EMI shielding performance.In addition,MXene aerogel/WPC composites also exhibit good anisotropic compressive strength,excellent thermal insulation and flame retardant properties.Such ultra-light,green and efficient multi-functional bio-carbon-based composites have great application potential in the high-end EMI shielding fields of aerospace and national defence industry,etc.
基金supported by the National Key Technology R&D Program of China (Grant Nos. 2020YFB1709301 and 2020YFB1709304)the National Natural Science Foundation of China (No. 52173036 and 52073107)+3 种基金the Central University Basic Research Fund of China (Grants 2021XXJS035)the Innovation and Talent Recruitment Base of New Energy Chemistry and Device (Grants B21003)the Opening Project of Key Laboratory of Polymer Processing Engineering (South China University of Technology),Ministry of Education (Grant No. KFKT2002)fund from Henan University of Science and Technology (2020-RSC02)
文摘The development of functional composites with excellent thermal management capabilities and electro-magnetic interference(EMI)shielding has become extremely urgent for keeping up with the continuous improvement of the operating speed and efficiency for electronic equipment.In this study,the biolog-ical wood-derived porous carbon(WPC)was determined as the supporting material to encapsulating polyethylene glycol(PEG),and a series of WPC/PEG/Fe_(3)O_(4) phase change composites(PCCs)with excel-lent shape stability,EMI shielding and thermal management capabilities were prepared via a simple vac-uum impregnation method.The Fe_(3)O_(4) magnetic particles modified PCCs have greatly improved the EMI shielding effectiveness(SE).The EMI SE of WP-4(7.5 wt.% Fe_(3)O_(4) in PEG)can be up to 55.08 dB between 8.2−12.4 GHz,however,the WP-0 without Fe_(3)O_(4) addition is only 40.08 dB.Meanwhile,the absorption ratio of electromagnetic waves(EMW)has also increased from 75.02%(WP-0)to 85.56%(WP-4),which effectively prevents secondary pollution.In addition,after wrapping a thin layer of polydimethylsiloxane resin(PDMS),the obtained WP-4 can maintain a high heat storage capacity(109.52 J/g)and good wa-ter stability.In short,the prepared WPC/PEG/Fe_(3)O_(4) PCCs have great potential application value in the thermal management and electromagnetic shielding requirements for electronic devices.
基金Jiangsu Province Key Laboratory of Biomass Energy and Materials(No.JSBEM-S-202101)Young Top Talent Program of Zhongyuan-Yingcai-Jihua,the Top-Notch Talent Program of Henan Agricultural University(No.30501034)National Natural Science Foundation of China(No.31901272).
文摘Expanding the application scenarios of wood-derived biochar guided by the conversion of traditional energy to new energy shows great promise as a field.As thrilling energy conversion apparatus,zinc-air batteries(ZABs)require cathode catalysts with high oxygen reduction reaction(ORR)and oxygen evolution reaction(OER)activities and stability.Herein,two-dimensional nickel-iron hydroxide nanosheets were creatively assembled in N-doped wood-derived biochar(NiFe-LDH@NC)by an in-situ growth method.The categorized porous organization in wood-derived biochar facilitates the rapid seepage of electrolytes and rapid diffusion of reaction gases.The unique interfacial structure of biochar and NiFe-LDH accelerates electron transfer during oxygen electrocatalysis,and endows NiFe-LDH@NC with first-class catalytic activity and durability for ORR and OER.The ZAB derived from NiFe-LDH@NC showed elevated discharge productivity and cycle endurance,making it promising for viable applications.This work provided a convenient way for the conversion of wood-derived biochar to high-value added electrocatalysts.
基金supported by the National Natural Science Foundation of China(NSFC,Grant Nos.51772060,51372052,and 51621091).
文摘Wood-derived carbon has a 3D porous framework composed of through channels along the growth direction,which is a suitable matrix for preparing electromagnetic wave(EMW)absorbing materials with low cost,light weight,and environmental friendliness.Herein,the carbonized wood decorated by short cone-like NiCo_(2)O_(4)(NiCo_(2)O_(4)@CW)with highly ordered straight-channel architecture was successfully manufactured through a facile calcination procedure.The horizontal arrangement of the through channels of NiCo_(2)O_(4)@CW(H-NiCo_(2)O_(4)@CW)exhibits a strong reflection loss value of-64.0 dB at 10.72 GHz with a thickness of 3.62 mm and a low filling ratio of 26 wt%(with the density of 0.98 g-cnf3),and the effective absorption bandwidth(EAB)is 8.08 GHz(9.92-18.0 GHz)at the thickness of 3.2 mm.The excellent microwave absorption(MA)property was ascribed to the ordered-channel structure with abundant interfaces and defects from NiCo_(2)O_(4)@CW,which could promote the interfacial polarization and dipole polarization.What is more,this advantageous structure increased the multiple reflections and scattering.Finite element analysis(FEA)simulation is carried out to detect the interaction between the prepared material and EMW when the ordered channels are arranged in different directions.This research provides a low-cost,sustainable,and environmentally friendly strategy for using carbonized wood to fabricate microwave absorbers with strong attenuation capabilities and light weight.
基金financially supported by the Hunan Provincial Natural Science Foundation of China (No.2020JJ2058)Forestry science and technology innovation of Hunan Province (No.XLK202107-3)+2 种基金Scientific Research Foundation of Hunan Provincial Education Department (No.18A159)Scientific Research Foundation of Central South University of Forestry and Technology (Nos.104–0452,2018YC003)the National Natural Science Foundation of China (No.52073064)。
文摘Wood-derived carbons have been demonstrated to have large specific capacities as the anode materials of lithium-ion batteries(LIBs). However, these carbons generally show low tap density and minor volumetric capacity because of high specific surface area and pore volume. Combination with metal oxide is one of the expected methods to alleviate the obstacles of wood-derived carbons. In this work, the composites of Mn O loaded wood-derived carbon fibers(CF@Mn O) were prepared via a simple and environmentally friendly method, showing decreased specific surface area due to the generation of Mn O nanoparticles on carbon fibers. Furthermore, the CF@Mn O compostites exhibit superior electrochemical performance as anode materials of LIBs, which show high reversible capacity in the range of 529-734 m Ah/g at a current density of 100 m A/g. The optimal CF@Mn O product(Mn O:carbon = 1:2) delivers reversible capacity of 734 and 265.3 m Ah/g at current density of 100 and 2000 m A/g, respectively. Besides, the material presents outstanding stability with coulombic efficiency around 100% after 200 cycles at a high current density of 400 m A/g, revealing a potential as promising anode materials for high-performance LIBs.
基金supported by the National Science Fund for Distinguished Young Scholars(No.51625801)Major Science and Technology Program for Water Pollution Control and Treatment in China(No.2017ZX07202-001-007)+4 种基金Guangdong Province Universities and Colleges Pearl River Scholar Funded Scheme(2017)Guangdong Provincial Science and Technology Project(No.2017A020216014)the National Natural Science Foundation of China(No.21777106)Pearl River S&T Nova Program of Guangzhou,China(No.201710010065)Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology(No.2020B1212060022)。
文摘The flow-through electro-Fenton(EF-T)reactor with WBC cathode was designed to remove florfenicol(FF).The activated WBC cathode was prepared by facile carbonization and activation methods,and featured high specific surface area,natural multi-channel structure,abundant oxygen-containing groups,good hydrophilicity,and excellent O_(2)reducing capacity.WBC cathode was located above Ti/Ru-IrO_(2)mesh anode.O_(2)evolved at the anode was carried to the inner wall of channel of WBC by the force of buoyancy and water flow,which increases oxygen source of H_(2)O_(2)generation at the cathode.The flow-through system by using WBC electrode promote the mass transfer of O_(2)and FF.The production amount of H_(2)O_(2)at activated WBC was 32.2 mg/L,which was almost twice as much as that at non-activated WBC(15.0 mg/L).FF removal ratio in EF-T system was 98%,which was much higher than that of traditional flow-by electro-Fenton(EF-B,33%)or single electrooxidation system(EO,16%).EF-T system has the lowest energy consumption(4.367 kWh/kg)among the three electrochemical systems.The cathodic adsorption,anodic electrooxidation,and EF reaction are responsible for the degradation of FF.After five consecutive cycle experiments,FF removal ratio was still 98%,indicating WBC has the good stability.
文摘目的研究木浆源甾醇对高脂高胆固醇仓鼠肝脏中胆固醇代谢基因表达的影响。方法测定空白组、高脂组、实验组仓鼠的质量、脏器重量、血清中总胆固醇(total cholesterol,TC)、高密度脂蛋白胆固醇(high density lipoprotein cholesterol,HDL-C)、甘油三酯(triglyceride,TG)水平。检测肝脏中胆固醇代谢相关调控基因m RNA表达水平及肝脏胆固醇含量和粪便固醇排泄量。结果木浆源甾醇可以极显著降低TC、TG、和Non HDL-C水平(P<0.01),同时极显著降低肝脏中胆固醇含量和肝脏重量(P<0.01),显著增加粪中固醇排泄量(P<0.05)。实验组肝脏中SREBP2、CYP7A1、HMG-Co A-R和LDL-R m RNA表达水平显著上调(P<0.05)。给予木浆源甾醇后可以改变肠道菌群多样性,增加有益菌减少有害菌数量。结论木浆源甾醇可能通过调控肝脏中胆固醇代谢相关基因的表达,抑制胆固醇的合成吸收并增加固醇的排泄,同时丰富肠道微生物多样性,增加有益菌数量,协同作用调控机体胆固醇的代谢。
