Three-dimensional(3D)ordered porous carbon is generally believed to be a promising electromagnetic wave(EMW)absorbing material.However,most research works targeted performance improvement of 3D ordered porous carbon,a...Three-dimensional(3D)ordered porous carbon is generally believed to be a promising electromagnetic wave(EMW)absorbing material.However,most research works targeted performance improvement of 3D ordered porous carbon,and the specific attenuation mechanism is still ambiguous.Therefore,in this work,a novel ultra-light egg-derived porous carbon foam(EDCF)structure has been successfully constructed by a simple carbonization combined with the silica microsphere template-etching process.Based on an equivalent substitute strategy,the influence of pore volume and specific surface area on the electromagnetic parameters and EMW absorption properties of the EDCF products was confirmed respectively by adjusting the addition content and diameter of silica microspheres.As a primary attenuation mode,the dielectric loss originates from the comprehensive effect of conduction loss and polarization loss in S-band and C band,and the value is dominated by polarization loss in X band and Ku band,which is obviously greater than that of conduction loss.Furthermore,in all samples,the largest effective absorption bandwidth of EDCF-3 is 7.12 GHz under the thickness of 2.13 mm with the filling content of approximately 5 wt%,covering the whole Ku band.Meanwhile,the EDCF-7 sample with optimized pore volume and specific surface area achieves minimum reflection loss(RL_(min))of−58.08 dB at 16.86 GHz while the thickness is 1.27 mm.The outstanding research results not only provide a novel insight into enhancement of EMW absorption properties but also clarify the dominant dissipation mechanism for the porous carbon-based absorber from the perspective of objective experiments.展开更多
Recently,developing carbon-based hybrid materials loaded with magnetic components has been generally regarded as a promising and practically feasible strategy when it comes to constructing lightweight electromagnetic ...Recently,developing carbon-based hybrid materials loaded with magnetic components has been generally regarded as a promising and practically feasible strategy when it comes to constructing lightweight electromagnetic wave absorbers.In the current work,reclaimed carbon black(CB)nanopowder was firstly produced by simple burning of wheat straw,which was then employed as sustainable carbon-based host materials(carrier)and successfully decorated Co@C nanoparticles via a simple thermal reduction process.Remarkably,both the as-fabricated nanocomposites and corresponding electromagnetic wave absorption performances could be effectively tuned by tailoring the dosage of the Co@C nanoparticles.The minimum reflection loss(RLmin)of–53.989 d B was achieved for CB/Co@C-2#at 2.28 mm thickness,meanwhile,CB/Co@C-3#was featured by a wide effective absorption band(EAB)of 6 GHz(6.72–12.72 GHz)at a 2.73 mm matching thickness,which covered the entire X band,suggesting that the CB/Co@C nanocomposites were an attractive candidate for electromagnetic wave absorber.According to the synergistic influence of dielectric loss and magnetic loss from CB and Co@C,respectively,as well as the properly matched impedance,a reasonable electromagnetic wave attenuation mechanism was illustrated.It is noteworthy that the preparation process of CB is a facile,recycled,and low-cost strategy for achieving nanoscale carbon-based absorbing materials,moreover,the CB/Co@C nanocomposites provide a reference for constructing lightweight dielectric-magnetic products with superb electromagnetic wave absorption performances.展开更多
基金supported by the National Natural Science Foundation of China under Grant No.52072196,52002199,52002200,52102106Major Basic Research Program of Natural Science Foundation of Shandong Province under Grant No.ZR2020ZD09+2 种基金the Natural Science Foundation of Shandong Province under Grant No.ZR2019BEM042,ZR2020QE063the Innovation and Technology Program of Shandong Province under Grant No.2020KJA004the Taishan Scholars Program of Shandong Province under No.ts201511034
文摘Three-dimensional(3D)ordered porous carbon is generally believed to be a promising electromagnetic wave(EMW)absorbing material.However,most research works targeted performance improvement of 3D ordered porous carbon,and the specific attenuation mechanism is still ambiguous.Therefore,in this work,a novel ultra-light egg-derived porous carbon foam(EDCF)structure has been successfully constructed by a simple carbonization combined with the silica microsphere template-etching process.Based on an equivalent substitute strategy,the influence of pore volume and specific surface area on the electromagnetic parameters and EMW absorption properties of the EDCF products was confirmed respectively by adjusting the addition content and diameter of silica microspheres.As a primary attenuation mode,the dielectric loss originates from the comprehensive effect of conduction loss and polarization loss in S-band and C band,and the value is dominated by polarization loss in X band and Ku band,which is obviously greater than that of conduction loss.Furthermore,in all samples,the largest effective absorption bandwidth of EDCF-3 is 7.12 GHz under the thickness of 2.13 mm with the filling content of approximately 5 wt%,covering the whole Ku band.Meanwhile,the EDCF-7 sample with optimized pore volume and specific surface area achieves minimum reflection loss(RL_(min))of−58.08 dB at 16.86 GHz while the thickness is 1.27 mm.The outstanding research results not only provide a novel insight into enhancement of EMW absorption properties but also clarify the dominant dissipation mechanism for the porous carbon-based absorber from the perspective of objective experiments.
基金the National Natural Science Foundation of China(Nos.51672144,51572137,51702181,52072196,52002199,52002200)the Major Basic Research Program of Natural Science Foundation of Shandong Province under Grant No.ZR2020ZD09+5 种基金the Shandong Provincial Key Research and Development Program(SPKR&DP)under Grant No.2019GGX102055the Natural Science Foundation of Shandong Province(Nos.ZR2019BEM042,ZR2020QE063)the Innovation and Technology Program of Shandong Province under Grant No.2020KJA004Guangdong Basic and Applied Basic Research Foundation(No.2019A1515110933)the China Postdoctoral Science Foundation(No.2020M683450)the Taishan Scholars Program of Shandong Province under No.ts201511034。
文摘Recently,developing carbon-based hybrid materials loaded with magnetic components has been generally regarded as a promising and practically feasible strategy when it comes to constructing lightweight electromagnetic wave absorbers.In the current work,reclaimed carbon black(CB)nanopowder was firstly produced by simple burning of wheat straw,which was then employed as sustainable carbon-based host materials(carrier)and successfully decorated Co@C nanoparticles via a simple thermal reduction process.Remarkably,both the as-fabricated nanocomposites and corresponding electromagnetic wave absorption performances could be effectively tuned by tailoring the dosage of the Co@C nanoparticles.The minimum reflection loss(RLmin)of–53.989 d B was achieved for CB/Co@C-2#at 2.28 mm thickness,meanwhile,CB/Co@C-3#was featured by a wide effective absorption band(EAB)of 6 GHz(6.72–12.72 GHz)at a 2.73 mm matching thickness,which covered the entire X band,suggesting that the CB/Co@C nanocomposites were an attractive candidate for electromagnetic wave absorber.According to the synergistic influence of dielectric loss and magnetic loss from CB and Co@C,respectively,as well as the properly matched impedance,a reasonable electromagnetic wave attenuation mechanism was illustrated.It is noteworthy that the preparation process of CB is a facile,recycled,and low-cost strategy for achieving nanoscale carbon-based absorbing materials,moreover,the CB/Co@C nanocomposites provide a reference for constructing lightweight dielectric-magnetic products with superb electromagnetic wave absorption performances.
