KuQuinone-sensitized cobalt oxide nanoparticles for photoelectrocatalytic oxygen evolution with visible light

Photocatalytic nanomaterials offer promising solutions for conducting chemical transformations under safe, green and sustainable conditions. In particular, the storage of solar energy into chemical bonds is an appealing but challenging goal in the field of artificial photosynthesis. Using water as the source of electrons and protons through the photodriven water oxidation (WO) reaction is at the core of this endeavour. In this work, we disclose photoactive hybrid nanomaterials designed through a dyadic approach. We exploit Co3O4 nanoparticles (NPs) covalently functionalized with a fully organic pentacyclic polyquinoid KuQuinone (KuQ) dye, providing a rare example of a noble metal-free photocatalytic dyadic nanomaterial (hereafter denoted as KuQ3Pn@Co3O4). KuQ3Pn@Co3O4 NPs have been characterized by electron microscopy and optical and core-level spectroscopy studies. When cast onto a SnO2 photoanode, they are active towards WO upon visible light irradiation (400-580 nm) with a faradaic efficiency for O2 evolution of ca. 90%. This work provides a novel contribution to the rational design and mechanistic understanding of hybrid photocatalytic nanomaterials relevant for energy and sustainable synthesis applications.