Redox-active Sn(II) to lead to SnFeO spinel as a bi-functional water splitting catalyst.

Despite several reports on metal ferrites for water splitting studies, SnFeO is a rarely explored spinel oxide. Herein, solvothermally prepared 5 nm SnFeO nanoparticles deposited on nickel foam (NF) behaves as a bi-functional electrocatalyst. In alkaline pH, the SnFeO/NF electrode exhibits oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) at moderate overpotentials and shows a fair chronoamperometric stability. Detailed study indicates that iron sites of the spinel are preferably active for the OER while the Sn sites not only enhance the electrical conductivity of the material but also favor the HER.