Enhanced hot electron generation by inverse metal–oxide interfaces on catalytic nanodiode

Identifying the electronic behavior of metal–oxide interfaces is essential for understanding the origin of catalytic properties and for engineering catalyst structures with the desired reactivity. For a mechanistic understanding of hot electron dynamics at inverse oxide/metal interfaces, we employed a new catalytic nanodiode by combining Co3O4 nanocubes (NCs) with a Pt/TiO2 nanodiode that exhibits nanoscale metal–oxide interfaces. We show that the chemicurrent, which is well correlated with the catalytic activity, is enhanced at the inverse oxide/metal (CoO/Pt) interfaces during H2 oxidation. Based on quantitative visualization of the electronic transfer efficiency with chemicurrent yield, we show that electronic perturbation of oxide/metal interfacial sites not only promotes the generation of hot electrons, but improves catalytic activity.