Abstract Scope |
Designing photoelectrodes by incorporation of photo-active nanomaterials is an emerging strategy to enhance photoelectrochemical performance of semiconducting metal oxides. The small diffusion paths through the ultrathin layer, large surface area, and exposing abundant active sites can effectively boost charge separation and charge transfer in photoelectrochemical water oxidation. Here, we investigate the influence of decorating graphene on the photoelectrochemical water oxidation performance of WO3/Nb:SrTiO3 photoanodes. The graphene-decorated photoanodes exhibit efficient charge transfer due to electronic and electrochemical properties of graphene edges, which leads to decreasing onset potential and increasing photocurrent density from 237 μA/cm2 to 763 μA/cm2 at 1.23 V vs RHE. In addition, such extremely thin layer can protect the photoelectrode from chemical corrosion without disturbing the light absorption. We discuss the role of graphene edges for photoelectrochemical water oxidation. Thus, these results can provide a new route for advanced designs of nanomaterial-based photoelectrochemical devices. |