Chemically Deposited Cobalt-Based Oxygen-Evolution Electrocatalysts on DOPA-Displaying Viruses

Filamentous bacteriophages were engineered to display 3,4-dihydroxy-l-phenylalanine (DOPA) onto which a cobalt oxide based oxygen-evolution catalyst (Co-OEC) spontaneously deposited at room temperature. Relative to the electrodeposited Co-OEC, the catalyst formed on the virus exhibited improved durability and current density in a small overpotential region, as well as decreased oxidation states for the formation of Co(OH)(2), as confirmed by electrochemical and X-ray photoelectron spectroscopy analysis. Chemically deposited Co(OH)(2) on the virus was oxidized to CoOOH during the water-oxidation process. Thus, the DOPA-displaying virus illustrates the affordability of a genetically engineered bacteriophage as a molecular support that can improve the catalytic performance of inorganic materials without any additional electrical energy.