TiO2 nanorod arrays decorated with exfoliated WS2 nanosheets for enhanced photoelectrochemical water oxidation

A novel three-dimensional (3D) photoanode consisting of TiO 2 nanorod arrays (TiO 2 NAs) coated by exfoliated WS 2 nanosheets was fabricated for enhanced photoelectrochemical water oxidation . Mixed phase WS 2 nanosheets with 1 T percentage of 55% were exfoliated by the lithium insertion, which were then coated on the top of TiO 2 NAs by a drop-casting method. By optimizing the loading amount of WS 2 , a maximum photocurrent of ∼1.8 mA/cm 2 could be obtained at +1.8 V vs. RHE under AM 1.5 irradiation (100 mW/cm 2 ), which is 2.3 times higher compared to the pure TiO 2 NAs (0.8 mA/cm 2 ). The enhanced photo-activity should be attributed to the presence of the mixed phase WS 2 nanosheets, which have excellent charge transport ability and can accept photogenerated holes for water oxidation.