Palladium sulfide nanoparticles attached MoS2/nitrogen-doped graphene heterostructures for efficient oxygen reduction reaction

A novel nanohybrid based on palladium sulfide nanoparticles uniformly dispersing on heterostructure of MoS2/nitrogen-doped graphene (PdxSy-MoS2/N-GR) was developed for catalyzing oxygen reduction reaction in alkaline medium. The nanohybrid demonstrated effectively catalytic performance with a positive onset potential of -0.141 V and half-wave potential of -0.214 V, along with high current response, which are comparable to a commercial Pt/C product. In addition, the nanohybrid also exhibited good stability and excellent methanol tolerance, significantly superior to those of the Pt/C. The obtained results were assumed to the synergistic effects produced by PdxSy, MoS2, and N-GR to enhance numbers of electroactive sites and charge conductivity. In addition, the large surface area of the MoS2/N-GR heterostructure effectively accelerated the electrolyte penetration and diffusion rate of reactant. The outstanding catalytic performance of the PdxSy-MoS2/N-GR opens up a novel approach for developing efficient and cost-effective catalyst towards ORR in alkaline fuel cell applications.