Uniform WMoSx nanoparticles attached graphene nanosheets as highly effective electrocatalyst for oxygen reduction reaction in alkaline medium.

Abstract Small and uniform bimetallic WMoS x nanoparticles well distributed on surface of thin graphene nanosheets (WMoS x -Gr) was prepared and investigated as an effective electrocatalysts for oxygen reduction reaction (ORR) in alkaline electrolyte. This material exhibited highly catalytic activity relative to a commercial Pt/C product. In this context, the material showed a large limit current density, positive onset potential (−0.05 V) as well as half wave potential (−0.13 V). In particularly, the superior durability and methanol tolerance of the as-synthesized material were also pronounced, as compared to Pt/C. The high ORR activity of the WMoS x -Gr material was assumed to the synergistic effect produced from a unique nanostructure of the WMoS x and the high surface area graphene with its excellent conductivity. The obtained results imply that such hybrid material can open a new type of highly efficient non-Pt catalyst for ORR in alkaline environment. Graphical abstract Image 1 Highlights • Uniform WMoS x nanoparticles dispersed graphene is prepared by a facile route. • The hybrid offers high catalytic performance for ORR, comparable to Pt/C. • The synergistic effect from WMoS x and graphene produces enhanced ORR performance. • The hybrid shows much better durability and methanol tolerance than Pt/C. [ABSTRACT FROM AUTHOR]