Facile synthesis of carbon-coated hematite nanostructures for solar water splitting

Carbon-coated hematite nanostructures for solar water splitting were prepared by a simple pyrolysis of ferrocene which showed a remarkable photocurrent of 2.1 mA cm−2 at 1.23 V vs. RHE, compared to a value of 0.5 mA cm−2 for hematite without the carbon layer. The carbon layer is a few nm thick covering the surface of hematite nanostructures. X-Ray photoelectron spectroscopy and X-ray absorption spectroscopy revealed that the electronic structure of hematite was significantly modified with the existence of oxygen vacancy, which was responsible for the remarkable photocurrent. The carbon layer plays an important role for the appearance of oxygen vacancy. The simple and cheap method could be scaled up easily which may pave the way for the practical application for efficient solar water splitting.