Efficient bifunctional catalysts for overall water splitting: porous Fe-Mo oxide hybrid nanorods

Efficient and inexpensive bifunctional catalysts for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) are essential for water splitting. Herein, we successfully prepare porous Fe-Mo oxide hybrid nanorods through a hydrothermal method followed by annealing at high temperature. They exhibit excellent catalytic activity for OER and HER in alkaline media, and produce a current density of 10 mA cm −2 at overpotentials of 200 and 66 mV. Besides, they work as bifunctional electrode materials for overall water splitting, achieving a current density of 10 mA cm −2 at a voltage of 1.52 V, and maintaining a current density of 60 mA cm −2 for 60 h. The unique morphology with self-supported structure can expose more active sites and facilitate charge transfer, and is not easy to peel off, thus it improves the catalytic activity and stability. This work therefore provides a valuable route for designing and fabricating inexpensive and high-performance catalytic materials for overall water splitting. In this work, binary metal oxide porous nanorods are synthesized and exhibit evidently small overpotentials for OER and HER. They also display remarkable stability by holding a current density of ±200 mA cm −2 for 85 h for OER/HER.