Tailoring 2D MoS2 heterointerfaces for promising oxygen reduction reaction electrocatalysis

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 0.885V (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.