Novel Fe2O3/{101}TiO2 nanosheet array films with stable hydrophobicity and enhanced photoelectrochemical performance

Single crystal TiO2 nanosheet (TNS) arrays with coexposed {101} and {001} facets were synthesized on FTO conductive glass directly, thorn-like Fe2O3 were deposited on the {101} surface of TNS by a chemical bath deposition method. Taking advantage of different energy band positions of {101} and {001} facets, the higher band offset value between Fe2O3 and {101} facets was achieved, which would accelerate the photoexcited electrons and holes separation between Fe2O3 and {101} facets of TNS and enhance photoelectrochemical properties. Furthermore, without modification by low energy chemicals, such novel Fe2O3/TNS heterostructure electrodes exhibited stability hydrophobicity. After UV irradiation for 240 min, the contact angle of the Fe2O3/TNS (80min) films retained hydrophobicity (134.8°), which is approximately 7.1 times higher than that of bare TNS films. The optimal composite photoelectrode exhibited the highest transient photocurrent intensity (48 μA), which is about 4.4 times superior over the bare TNS. The superior photoelectrochemical properties and stability hydrophobicity were attributed to the suitable band edge positions and hydrophobic thorn-like α-Fe2O3.