Synthesis of platinum/metal oxide nanostructure based on elastin protein fiber template and application in lithium-oxygen battery

Abstract

The synthesis method of functional one-dimensional (1D) platinum-cobalt oxide and platinum-manganese oxide using self-assemble GPG-AG3 fusion protein was proposed and verified. The AG3 and GPG peptide sequence were joined to enable mineralization of inorganic materials on the self-assemble fibers surface and thus produce the nanoscale heterostructures by a hydrothermal treatment and annealing. Field-Emission Scanning Electron Microscopy (FESEM), Transmission Electron Microscopy (TEM), X-Ray Diffraction (XRD) were used to investigate the morphologies, structure and composition of the prepared samples. The GPG-AG3 was proved to be able to assemble into nanofibers with an average thickness of 50-100 nm and bind with the metal ions. The synthesized cobalt oxides were mainly Co3O4 and manganese oxides were mainly Mn2O3 and MnO according to XRD measurements. The hybrids were tested as cathode for Lithium Oxygen Batteries (LOBs) and showed low overpotentials during charge and discharge. The performance might be attributed to the unique 1D structure of the composites, which can facilitate oxygen diffusion and catalytic reaction at same time.