Tailoring 2D MoS2 heterointerfaces for promising oxygen reduction reaction electrocatalysis

Abstract

Two-dimensional MoS₂ has been proposed to be an effective low-cost electrocatalyst for the oxygen reduction reaction (ORR) due to its appropriate electronic configuration. However, the catalytic activity of pristine MoS₂ is still far from what is expected. Herein, we rationally synthesize ultrathin Ni₃S₂/MoS₂ heterostructured nanosheets for a direct 4-electron transfer ORR. A half-wave potential of 0.885 V (versus the reversible hydrogen electrode (RHE)) is achieved in 0.1 M KOH, which is 22 mV more positive than that of commercial 20 wt% Pt/C. The abundant heterointerfaces in Ni₃S₂/MoS₂ not only provide numerous highly active Mo edges/Mo–Ni–S sites and accelerate charge transport but also enable the binding of more oxygen-containing intermediates. This work is expected to inspire the design of advanced MoS₂-based materials for diverse applications.