Nickel-tungsten sulfides nanostructures assembled nitrogen-doped graphene as a novel catalyst for effective oxygen reduction reaction

• Published in: Journal of electroanalytical chemistry (Lausanne, Switzerland) Vol. 848; p. 113343
• Main Authors: Bich, H.N., Thi, M.L.N., Son, N.T., Bui, Q.B., Ai-Le, P.H., Nhac-Vu, H.-T.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.09.2019; Elsevier Science Ltd
• Subjects: Bimetals; Charge transfer; Durability; Electrocatalyst; Electronic structure; Fuel cells; Graphene; Nanostructure; Nickel; Nickel‑tungsten sulfides; Nitrogen; Nitrogen-doped graphene; Oxygen reduction reaction; Oxygen reduction reactions; Sulfides; Tungsten; Nickel‑tungsten sulfides; Electrocatalyst; Nitrogen-doped graphene; Oxygen reduction reaction
• ISSN: 1572-6657; 1873-2569
• DOI: 10.1016/j.jelechem.2019.113343

Here we propose a novel nanohybrid of bimetallic nickel‑tungsten sulfides nanostructures uniformly distributed on nitrogen-doped graphene with efficient ORR performance in 0.1 M KOH electrolyte. The material exhibits high limit current density, positive onset potential (+0.97 V) and half-wave potential (+0.82 V), and a small Tafel slope of 101 mV/dec, which are comparable to a commercial Pt/C (20 wt%). In addition, the material also shows superior stability, durability, and methanol tolerance than those of the Pt/C. The good performance can be credited to the synergistic effects of bimetallic nickel‑tungsten sulfides, which lead to the modification of electronic structure with the enhanced electroactive sites for ORR. In addition, the large surface area and high conductivity of nitrogen-doped graphene stably disperse active metals with good interaction to effectively avoid reaggregation/agglomeration and promote the charge transfer at the interface. The achieved results of this work present efficient and durable electrocatalyst, highly potential towards ORR in alkaline fuel cell applications. [Display omitted] •Hybrid of NiW-S nanostructures dispersing on NG nanosheets is facilely prepared.•The synergistic effect between Ni-W-S and NG increases ORR performance.•The hybrid produces good catalytic activity for ORR in alkaline medium.•The hybrid shows comparative activity but superior stability and MeOH tolerance to Pt/C.