Graphitic carbon nitride nanosheet coated carbon black as a high-performance PtRu catalyst support material for methanol electrooxidation

PtRu supported on a C@g-C3N4 NS (g-C3N4 nanosheet coated Vulcan XC-72 carbon black) catalyst has been prepared by a microwave-assisted polyol process (MAPP). The results of electrochemical measurements show that the PtRu/C@g-C3N4 NS catalyst has excellent activity due to more uniform dispersion and smaller size of PtRu nanoparticles (PtRu NPs), and higher stability ascribed to the stronger metal-support interaction (SMSI) between PtRu NPs and the composite support. Physical characterisation using techniques such as X-ray diffraction (XRD), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) has indicated that the bulk g-C3N4 shell outside of the as-prepared C@bulk g-C3N4 (bulk g-C3N4 coated Vulcan XC-72 carbon black, C@bulk g-C3N4) indeed exfoliated to layered g-C3N4 nanosheets and formed a composite material of Vulcan XC-72 coated with g-C3N4 nanosheets. Furthermore, the results indicate that the mass catalytic activity of the PtRu/C@g-C3N4 NS catalyst substantially enhanced, which is a factor of 2.1 times higher than that of the PtRu/C catalyst prepared by the same procedure and the accelerated potential cycling tests (APCTs) show that the PtRu/C@g-C3N4 NS catalyst possesses 14% higher stability and much greater poison tolerance than as-prepared PtRu/C. The significantly enhanced performance of the PtRu/C@g-C3N4 NS catalyst is ascribed to the following reasons: the inherently excellent mechanical resistance and stability of g-C3N4 nanosheets in acidic and oxidative environments; the increased electron conductivity of the support by forming a core-shell structure of C@g-C3N4 NS; SMSI between metal NPs and the composite support. Based on this novel approach to fabricate a C@g-C3N4 NS hybrid nanostructure, many other interesting applications might also be discovered.