Novel Composites of α-Fe2O3 Tetrakaidecahedron and Graphene Oxide as an Effective Photoelectrode with Enhanced Photocurrent Performances

Novel composites composed of alpha-Fe2O3 tetrakaidecahedrons and graphene oxide have been easily fabricated and demonstrated to be efficient photoelectrodes for photoelectrochemical water splitting reaction with superior photocurrent response. alpha-Fe2O3 tetrakaidecahedrons are facilely synthesized in a green manner without any organic additives and then modified with graphene oxide. The morphological and structural properties of alpha-Fe2O3/graphene composite are intensively investigated by several means, such as X-ray diffraction, field-emission scanning electron microscope, transmission electron microscope, X-ray photoelectron spectroscopy, Fourier Transform infrared spectroscopy, and Raman spectroscopy. The tetrakaidecahedronal hematite particles have been indicated to be successfully coupled with graphene oxide. Systematical photoelectrochemical and impedance spectroscopy measurements have been carried out to investigate the favorable performance of alpha-Fe2O3/graphene composites, which are found to be effective photoanodes with rapid, steady, and reproducible feature. The coupling of graphene with alpha-Fe2O3 particles has greatly enhanced the photoelectrochemical performance, resulting in higher photocurrent and lower onset potential than that of pure alpha-Fe2O3. This investigation has provided a feasible method to synthesize alpha-Fe2O3 tetrakaidecahedron and fabricate an efficient alpha-Fe2O3/graphene photoelectrode for photoelectrochemical water oxidation, suggesting a promising route to design noble metal free semiconductor/graphene photocatalysts.