Constructing Conductive Channels between Platinum Nanoparticles and Graphitic Carbon Nitride by Gamma Irradiation for an Enhanced Oxygen Reduction Reaction

Abstract

Electrocatalytic performance of low-cost graphitic carbon nitride (g-C₃N₄) is greatly limited by its conductivity. In this work, an innovative method, gamma irradiation technology, was used to efficiently synthesize g-C₃N₄/Pt nanoparticle (CN/Pt) nanocomposites, which can construct conductive channels between the nanostructure g-C₃N₄ and supported platinum nanoparticles (PtNPs). Then, the as-prepared CN/Pt nanocomposites were applied in the oxygen reduction reaction (ORR) as an electrocatalyst, which shows a small Tafel slope and the fast four-electron transfer path in the ORR. The oxygen reduction performance over the CN/Pt nanocomposite is much superior to that of the commercial Pt/C and mostly reported in g-C₃N₄-based electrodes. Experimental results have confirmed the fast charge transfer between PtNPs and g-C₃N₄ through a metal-support interaction, and using gamma irradiation technique to disperse PtNPs on g-C₃N₄ proves to be an effective strategy to enhance the catalytic performance of g-C₃N₄ in ORR. Therefore, gamma irradiation may possess great potential for preparing CN/Pt nanocomposites as a highly efficient ORR catalyst.