Yongpeng Lei1 (*), Qi Shi2,4, Cheng Han2, Bing Wang2, Nan Wu2, Hong Wang2, and Yingde Wang2,3 (*)
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1 College of Basic Education, National University of Defense Technology, Changsha 410073, China 2 Science and Technology on Advanced Ceramic Fiber and Composites Laboratory, National University of Defense Technology, Changsha 410073, China 3 College of Materials Science and Engineering, Wuhan Textile University, Wuhan 430074, China 4 Luoyang Ship Material Research Institute, Luoyang 471039, China
Carbon-based metal-free catalysts are a promising substitute for the rare andexpensive platinum (Pt) used in the oxygen reduction reaction. We herein reportN-doped graphene (NG) that is exquisitely integrated into highly conductiveframeworks, simultaneously providing more active sites and higher conductivity.The NG was in situ grown on carbon fibers derived from silk cocoon (SCCf) usinga simple one-step thermal treatment. The resulting product (NG-SCCf), possessinga meso-/macroporous structure with three-dimensional (3D) interconnectednetworks, exhibits an onset potential that is only 0.1 V less negative than thatof Pt/C and shows stability and methanol tolerance superior to those of Pt/C inalkaline media. Moreover, in the absence of Pt as co-catalyst, NG-SCCf shows aphotocatalytic H2 production rate of 66.0 μmol·h–1·g–1, 4.4-fold higher than thatof SCCf. This outstanding activity is intimately related to the in situ grown NG,hierarchically porous structure, and 3D interconnected networks, which notonly introduce more active sites but also enable smooth electron transfer,mass transport, and effective separation of electron-hole pairs. Considering theabundance of the green raw material in combination with easy and low-costpreparation, this work contributes to the development of advanced sustainablecatalysts in energy storage/conversion fields, such as electro- and photocatalysis.