Co₃O₄/CoS₂ Heterostructure: Synergistic Interfacial Coupling Induced Superior Electrochemical Performance for Hydrazine Oxidation Reaction

This work reports the fabrication of a Co 3 O 4 /CoS 2 heterostructure using a facile and low-temperature hydrothermal technique for overall hydrazine-assisted water splitting (OHzWS). The structural analyses using physical characterization techniques confirm the coexistence of Co 3 O 4 and CoS 2 phases with a significant interfacial interaction. The developed Co 3 O 4 /CoS 2 heterostructure shows superior electrochemical HzOR performance compared to individual Co 3 O 4 and CoS 2 phases. It could deliver a current densities of 10 and 100 mA/cm 2 at 240 and 340 mV, respectively. In addition, it delivers a high current density of 300 mA/cm 2 @ 480 mV without using any electrochemically active and expensive metallic substrate such as nickel foam, cobalt foam, etc. Furthermore, overall hydrazine-assisted water splitting by the Co 3 O 4 /CoS 2 heterostructure required a low cell potential of 0.49 V, which is 1.35 V less than that for the overall conventional water splitting (10 mA/cm 2 @ 1.84 V). Additionally, the heterostructured catalyst is electrochemically stable for 3000 continuous cycles.