Black phosphorus incorporated cobalt oxide: Biomimetic channels for electrocatalytic water oxidation

Learning from nature photosynthesis, the development of efficient artificial catalysts for water oxidation is an ongoing challenge. Herein, a lamellar cobalt oxide (CoO), black phosphorus (BP) and reduced graphene oxide (RGO) hybrid electrocatalyst is reported. BP domains are anchored on RGO and coated with CoO via P–O bonds. The widespread P–O bond network constitutes the proton acceptor and forms a proton exit channel, akin to the use of Asp61 in Photosystem II (PSII). The innermost kernel layer RGO serves as the current collector and forms an electron exit channel, mimicking the function of Tyr161 for charge transfer. The outermost encapsulation CoO layer acts as water oxidation catalyst (WOC). These biology-inspired features endow an outstanding OER performance of the hybrid material with a low overpotential of 206 mV at a current density of 10 mA cm−2. This work provides a new design guide for OER electrocatalysts through constructing two specialized channels for proton and electron transfer.