Search

Fe-N-C Catalysts: Direct Growth of Carbon Nanotubes Doped with Single Atomic Fe-N4 Active Sites and Neighboring Graphitic Nitrogen for Efficient and Stable Oxygen Reduction Electrocatalysis (Adv. Funct. In article number 1906174, Jia Li, Lin Gan, Feiyu Kang, and co-workers report the direct growth of carbon nanotubes doped with Fe-N SB 4 sb moieties for improved electrocatalytic stability in the cathodic oxygen reduction reaction (ORR) in proton-exchange-membrane fuel cells. By increasing the neighboring graphitic nitrogen, the Fe-N SB 4 sb moieties also show enhanced activity due to the modified spin state of the Fe center and thereby optimized binding energy with ORR intermediates. [Extracted from the article]

Efficient thermal dissipation is one of the most critical factors constraining the development of modern microelectronic devices. Placing vertically aligned carbon nanotubes (VACNTs) with anisotropic thermal conductive between high-power devices and heat sink such as copper plate can improve the interfacial thermal conductance. Due to the limited contact area between CNTs and the surface of the devices, direct use of ACNTs as thermal interface material fails to meet people's expectations. Here, we employ reduced graphene oxide (rGO) as the substrate for the growth of CNT arrays. VACNTs grown on rGO (rGO-ACNT) by chemical vapor deposition are then used as thermal conducting filler in epoxy resin. Compared with direct contact between CNT and the interface, using CNT and reduced graphene oxide junction to form contact with the surface can improve heat transfer efficiency. The resultant composite film exhibited excellent thermal conductivity at 9.62 W m−1 K−1 along the thickness direction. The obtained rGO-ACNT and its composite present higher thermal conductivity and heat transfer ability than ACNT. This strategy offers an insight into the easy preparation of flexible and highly thermal conductive composite materials, which may enable potential applications in advanced electronic devices. [ABSTRACT FROM AUTHOR]