Electrocatalytic performance of low-cost graphitic carbon nitride (CN) is greatly limited by its limited conductivity and small specific surface area. Herein, a simple and cost-effective idea to produce novel nanocomposite is constructed by the CN and cetyl trimethyl ammonium bromide functionalized carbon black (CB) anchored platinum nanoparticles as highly efficient oxygen reduction catalysts based on gamma irradiation. The assembled carbon nitride/positive carbon black anchoring PtNPs (Pt/CN 2 -CB + 1 ) catalyst exhibits significantly improved specific surface area, high graphitization, and uniformly dispersed ultra-small platinum nanoparticles. For the oxygen reduction reaction (ORR) performance, the catalyst shows more positive onset-potential (0.93 V versus RHE) and larger diffusion limiting current density (5.65 mA cm −2 ) compared with benchmark Pt/C catalysts in alkaline medium. Moreover, the Pt/CN 2 -CB + 1 catalyst exhibits a small Tafel slope (92 mV dec −1 ). Besides, the catalyst was demonstrated the remarkable methanol tolerance and good long-term stability under working conditions. This work provides a new and effective γ -rays irradiation for synthesizing the carbon nitride catalysts for energy conversion and storage applications.

We systematically investigate interfacial modification mechanisms on interfacial structure, mechanical and antifatigue performances of carbon fiber/epoxy (CF/EP) composites. The same interfacial shear strength (IFSS) was achieved by reasonable experiment design based on three explored mechanisms: (i) Ar plasma treatment for mechanical interlocking mechanism, (ii) UV-induced grafting acrylic acid for chemical bonding effect and (iii) carbon nanotubes electrophoretic deposition for transition layer theory. We found that the interface layer thickness and modulus of composites vary greatly due to different interfacial modification mechanisms. The damage resistance can be improved by increasing the propagation paths or hindering the propagation direction of the destructive cracks. Under the condition of the same interfacial strength, the variation trend of mechanical strength and fatigue properties were signfificantly different owing to the different interface microstructure. The nanotube deposition method has advantages in flexural strength, tensile strength and storage modulus, because the formed gradient interface layer has the dual effects of strengthening, toughening resin and increasing stress transfer efficiency. Plasma etching method is superior to the other two methods in residual bending strength retention because the mechanical interlocking in the interface micro-region can improve the stiffness of the composite and hinder the propagation of cracks. UV-induced grafting method is beneficial in improving the tensile strength of composites, because it has low damage to the mechanical strength of fiber. Therefore, when the interfacial strength is the same, carbon nanotubes electrophoretic deposition among the three modification methods has more attractive application prospects.

In this article, we utilized a facile approach for growth of carbon nanotubes onto the surface of carbon fibers by microwave plasma‐enhanced chemical vapor deposition to improve the interfacial properties of composites. By adjusting the deposition time, the length and density of carbon nanotubes could be controlled, and the results of Brunauer–Emmett–Teller testing indicated that the specific surface area was increased with the deposition time prolonged, which improve the contact area between fiber and resin matrix. The interfacial shear strength of the composites increased significantly with increasing in deposition time. When the deposited time reached 15 min, the interfacial shear strength of carbon fiber/epoxy composites increased 153%, reaching to 129.92 Mpa. On the basis of investigation for the relationship between the interfacial properties and the micro‐structures of composites, we found that the propagation path of transverse cracks on interface increased with the increasing of interfacial properties. POLYM. COMPOS., 39:E1262–E1268, 2018. © 2018 Society of Plastics Engineers