A Highly Efficient Heterostructure Nanorod Bifunctional Electrocatalyst for Realizing Enhanced Overall Water Splitting at a Large Current Density

Exploring efficient, low cost and stable electrocatalysts working at large current densities is crucial for upgrading the current industrial electrochemical water splitting. Herein, a novel FeS2/Fe-Ni3S2 heterostructure was successfully prepared via a simple one-step in situ hydrothermal vulcanization using F- regulation engineering. The FeS2/Fe-Ni3S2 heterostructure array exhibits low overpotentials for both the OER (180 mV @ 10 mA cm(-2) and 300 mV @ 1 A cm(-2)) and the HER (105 mV @ 10 mA cm(-2) and 344 mV @ 1 A cm(-2)) with high stability operating at 1 A cm(-2) for 1000 h. In addition, the water-splitting system only needs 1.5 V to reach 10 mA cm(-2) and shows prolonged stability of more than 1200 h at 1 A cm(-2). The DFT calculations show that the electrons redistribute at the interface and favor the chemisorption of hydrogen and oxygen-containing intermediates. This work highlights a novel, low cost and practical electrode for industrial electrochemical water splitting.