0D–2D Schottky heterostructure coupling of FeS nanosheets and Co9S8 nanoparticles for long-term industrial-level water oxidation

The effective electron and interface/structural coupling for heterostructure electrocatalyst is the key to regulating the intrinsic activity and stability for oxygen evolution reaction (OER). Herein, a facile strategy is developed to fabricate well-dispersed zero-dimensional (0D) metallic Co 9 S 8 nanoparticles on two-dimensional (2D) FeS nanosheets, forming FeS-Co 9 S 8 Schottky heterostructures with abundant heterointerfaces as OER electrocatalyst. The strong electronic coupling between FeS and Co 9 S 8 expedites electrons flow from Fe atoms in FeS nanosheets to Co atoms in tetrahedron sites (Co Td ), thereby leading to the structural integrity of the heterostructure and the constant exposure of active sites. Operando Raman spectroscopy also indicates the Co sites in the FeS-Co 9 S 8 Schottky heterostructure are OER active sites. Therefore, FeS-Co 9 S 8 heterostructure supported by iron foam (FeS-Co 9 S 8 /IF) shows the remarkable activity and durability, achieving an industrial-level 500 mA·cm −2 current density at an overpotential of only 332 mV and maintaining for 100 h. This work demonstrates that constructing Schottky heterostructure interface with strong coupling effect may be a good strategy for excellent catalytic performances.