Oxygen reduction reaction properties of vacuum-deposited Pt on thermally grown epitaxial graphene layers

We prepared platinum nanostructures on epitaxial graphene layers (EGLs) generated via the thermal annealing of SiC(0001) substrates [Pt/EGLs/SiC(0001)], and the oxygen reduction reaction (ORR) properties were investigated. 4H_ and 6H_SiC(0001) substrates were annealed at 1600 & DEG;C in a vacuum to generate EGLs through the sublimation of Si atoms from the Si-terminated SiC(0001) substrate surfaces. Subsequently, a 1.2 nm thick Pt layer was vacuum-deposited on the EGLs/SiC(0001) surfaces at 10(-8) Pa to synthesize Pt/EGLs/SiC(0001) nanostructures. Furthermore, the Pt nanostructures were fabricated separately on a 500 eV hydrogen-ion-beam (H-2(+)-beam) irradiated EGL/6H_SiC(0001) [Pt/H-2(+)-EGLs/SiC(0001)]. The ORR properties of the three vacuum-synthesized Pt/EGLs/SiC(0001) samples were evaluated, and the Pt/H-2(+)-EGLs/SiC(0001) surface revealed improved electrochemical structural stability, that is, enhanced ORR durability relative to the non-H-2(+)-irradiated Pt/EGLs/SiC(0001) surfaces.

Automated summary

In this study, platinum nanostructures were prepared on epitaxial graphene layers, and their oxygen reduction reaction (ORR) properties were investigated. It was found that hydrogen-ion irradiation improved the electrochemical structural stability and ORR durability of the Pt nanostructures.