Graphene Supported Co-g-C₃N₄ as a Novel Metal–Macrocyclic Electrocatalyst for the Oxygen Reduction Reaction in Fuel Cells

Abstract

Graphitic carbon nitride (g-C3N4) polymer was doped with cobalt species and supported on a similar sp(2) structure graphene, to form a novel nitrogen-metal macrocyclic catalyst for the oxygen reduction reaction (ORR) in alkaline fuel cells. The structural characterizations confirmed the formation of Co-N bonds and the close electron coupling between Co-g-C3N4 and graphene sheets. The electrocatalytic measurements demonstrated Co-g-C3N4-catalyzed reduction of oxygen mainly in a four electron pathway. The improvement of ORR activity is closely related to the abundant accessible Co-Nx active sites and fast charge transfer at the interfaces of Co-g-C3N4/graphene. Also, Co-g-C3N4@graphene exhibited comparable ORR activity, better durability, and methanol tolerance ability in comparison to Pt/C, and bodes well for a promising non-noble cathode catalyst for the application of direct methanol fuel cells. The chemical doping strategy in this work would be helpful to improve other present catalysts for fuel cell applications.

A visible light induced photoelectrochemical aptsensor constructed by aligned ZnO@CdTe core shell nanocable arrays/carboxylated g-C3N4 for the detection of Proprotein convertase subtilisin/kexin type 6 gene

“…1F presented the XRD patterns of g-C 3 N 4 and carboxylated g-C 3 N 4 . For g-C 3 N 4 (above line), two peaks confirmed a graphitic-like layer structure (Liao et al 2012;Liu and Zhang 2013). The peak at 13.1 o should be assigned to (100) peak corresponding to in-planar ordering of tri-s-triazine units with distance of 0.676 nm.…”

Co-porphyrin/carbon nitride hybrids for improved photocatalytic CO2 reduction under visible light

“…3b) can be assigned to three signals which correspond to pyridinic N (C=N-C, 398.8 eV), tertiary nitrogen (N-C3, 400.1 eV) and hydrogen-bonded N (NH2/NH, 401.2 eV). [29,30] For POM (Fig. 3c), additional signals at 400.2 eV and 397.6 eV were ascribed to the kinds of N in the porphyrin rings, both of which are replaced by a peak at 398.4 eV from Co-N in Co-POM (Fig.…”

Fabrication of TiO2/Co-g-C3N4 heterojunction catalyst and its photocatalytic performance

“…After the incorporation of cobalt into g-C 3 N 4 networks, the XRD pattern shows a significant intensity decrease and broadening of the (002) peak at 27.4°. Together with the absence of the peak at ~13°, suggesting that cobalt ions are embedded into in-planes of carbon nitride sheet [14]. The blue line in Fig.…”

“…2 illustrates the high-resolution XPS spectra of Co. The peak at ~781.2 eV can be ascribed to the Co(Ⅱ ) state in the form of Co-N x [14]. This value is higher than that of metallic Co (~779 eV) and Co oxide (~780 eV) as a result of the increased electronegativity of N (3.04) compared to that of Co (1.88) and O (2.55).…”