To mitigate secondary electromagnetic pollution,there is an urgent need to develop absorption-dominant electromagnetic interference(EMI)shielding materials with low density,reduced thickness,lightweight construction,f...To mitigate secondary electromagnetic pollution,there is an urgent need to develop absorption-dominant electromagnetic interference(EMI)shielding materials with low density,reduced thickness,lightweight construction,flexibility,exceptional mechanical strength,and superior electrothermal and photothermal properties,particularly for flexible and wearable electronics.In this regard,we designed an absorption-based composite film comprising carbon nanotubes(CNT)and α-Fe_(2)O_(3),featuring a CNT layer sandwiched between twoα-Fe_(2)O_(3)layers on the upper and lower surfaces.This composite film was fabricated through an electrodeposition process followed by a thermal annealing procedure to achieve enhanced EMI shielding performance along with improved electrothermal and photothermal properties.The strategically designed sandwich structure allows the rough surface of the upper α-Fe_(2)O_(3)layer to not only improve the impedance mismatch between free space and the composite film,facilitating the penetration of incident electromagnetic(EM)waves into the film and promoting increased EM absorption rather than reflection,but also to enhance electrical conductivity,thereby improving electron mobility and density.Consequently,the average total shielding effectiveness(SE)of the CNT/Fe_(16)-300 composite demonstrates remarkable EMI shielding effectiveness(EMI SE:56.8 dB).Furthermore,the alteration in the absorption-to-reflection ratio(A/R)signifies a transition in the EMI shielding mechanism from reflection(0.69 for the pristine CNT film)to absorption(1.86 for the CNT/Fe_(16)-300)with the incremental deposition of α-Fe_(2)O_(3)nanoparticles.This work presents a feasible manufacturing approach for developing composite films with a sandwich structure that exhibits absorption-dominant EMI shielding capabilities,contributing to advancements in thermal management and multifunctional electromagnetic shielding applications.展开更多
An innovative photocatalyst, Carbon nanotube （CNT） supported Ce-TiO2 nanocomposite was successfully synthesized via modi-fied sol gel method and investigated in a batch reactor for abolition of phenol under UV light...An innovative photocatalyst, Carbon nanotube （CNT） supported Ce-TiO2 nanocomposite was successfully synthesized via modi-fied sol gel method and investigated in a batch reactor for abolition of phenol under UV light spectrum. Characterization of catalyst micro-structure and internal properties were done by means of X-ray diffraction （XRD）, Brunauer-Emmett-Teller （BET）, scanning electron micros-copy （SEM）, transmission electron microscopy （TEM） and UV-vis diffuse reflectance spectra （DRS）. Ce doping can inhibit phase transfor-mation from anatase to rutile and eliminate the recombination of electron-hole pairs in the catalyst. The presence of CNT in TiO2 composite can both increase the photoactivity under UV and change surface properties to achieve sensitivity to visible light. The optimum mass ratio of CNT support and cerium （Ce） dopant in TiO2 was the prominent factor to harvest CNT/Ce-TiO2 photocatalyst nanocomposite. The results demonstrated that optimum mass ratio of CNT：TiO2：Ce was 0.02：1.0：0.06, which resulted in the great performance of the photocatalyst to de-grade about 94% of phenol in a 50 mg/L solution in only 3 h. In this paper, dissimilar role of CNT support and Ce dopant in the TiO2 photo-catalysis of phenol was also discussed.展开更多
基金financially supported by the National Natural Science Foundation of China(Nos.52222202 and 51772310)Chinese Academy of Sciences Key Research Program of Frontier Sciences(No.QYZDY-SSWJSC031)Shanghai Pilot Program for Basic Research-Chinese Academy of Science,Shanghai Branch(No.JCYJ-SHFY-2021-001).
文摘To mitigate secondary electromagnetic pollution,there is an urgent need to develop absorption-dominant electromagnetic interference(EMI)shielding materials with low density,reduced thickness,lightweight construction,flexibility,exceptional mechanical strength,and superior electrothermal and photothermal properties,particularly for flexible and wearable electronics.In this regard,we designed an absorption-based composite film comprising carbon nanotubes(CNT)and α-Fe_(2)O_(3),featuring a CNT layer sandwiched between twoα-Fe_(2)O_(3)layers on the upper and lower surfaces.This composite film was fabricated through an electrodeposition process followed by a thermal annealing procedure to achieve enhanced EMI shielding performance along with improved electrothermal and photothermal properties.The strategically designed sandwich structure allows the rough surface of the upper α-Fe_(2)O_(3)layer to not only improve the impedance mismatch between free space and the composite film,facilitating the penetration of incident electromagnetic(EM)waves into the film and promoting increased EM absorption rather than reflection,but also to enhance electrical conductivity,thereby improving electron mobility and density.Consequently,the average total shielding effectiveness(SE)of the CNT/Fe_(16)-300 composite demonstrates remarkable EMI shielding effectiveness(EMI SE:56.8 dB).Furthermore,the alteration in the absorption-to-reflection ratio(A/R)signifies a transition in the EMI shielding mechanism from reflection(0.69 for the pristine CNT film)to absorption(1.86 for the CNT/Fe_(16)-300)with the incremental deposition of α-Fe_(2)O_(3)nanoparticles.This work presents a feasible manufacturing approach for developing composite films with a sandwich structure that exhibits absorption-dominant EMI shielding capabilities,contributing to advancements in thermal management and multifunctional electromagnetic shielding applications.
基金Project supported by Research University Grant Scheme (Project A/C No.814004)the Malaysian Technology Development Corporation (MTDC) under the Commercialization of Research and Development Fund (CRDF) (MBF065-USM/05)
文摘An innovative photocatalyst, Carbon nanotube （CNT） supported Ce-TiO2 nanocomposite was successfully synthesized via modi-fied sol gel method and investigated in a batch reactor for abolition of phenol under UV light spectrum. Characterization of catalyst micro-structure and internal properties were done by means of X-ray diffraction （XRD）, Brunauer-Emmett-Teller （BET）, scanning electron micros-copy （SEM）, transmission electron microscopy （TEM） and UV-vis diffuse reflectance spectra （DRS）. Ce doping can inhibit phase transfor-mation from anatase to rutile and eliminate the recombination of electron-hole pairs in the catalyst. The presence of CNT in TiO2 composite can both increase the photoactivity under UV and change surface properties to achieve sensitivity to visible light. The optimum mass ratio of CNT support and cerium （Ce） dopant in TiO2 was the prominent factor to harvest CNT/Ce-TiO2 photocatalyst nanocomposite. The results demonstrated that optimum mass ratio of CNT：TiO2：Ce was 0.02：1.0：0.06, which resulted in the great performance of the photocatalyst to de-grade about 94% of phenol in a 50 mg/L solution in only 3 h. In this paper, dissimilar role of CNT support and Ce dopant in the TiO2 photo-catalysis of phenol was also discussed.
