One-step in-situ formation of TiO2 nanosheets interconnected hematite photoanode for enhanced water oxidation

Abstract In this study, by using a facile one-pot hydrothermal method, a Ti3C2 MXene derived TiO2 nanosheets/hematite photoanode with interconnected structures is fabricated via the in-situ chemical etching and exfoliation of bulk Ti3AlC2 powder. Compared to the pristine Fe2O3 film, the as-obtained Fe2O3/TiO2 photoanode exhibits an increased photocurrent density of 1.72 mA cm−2 at 1.23 V vs. RHE, and a further improved performance of 2.03 mA cm−2 at 1.23 V vs. RHE accompanied by a cathodic shift in the onset potential are also achieved after the loading of FeNiOOH cocatalyst. Further characterizations reveal that the enhanced PEC performance of Fe2O3/TiO2 photoanode can be ascribed to the facilitated charge separation and transport as well as the accelerated OER kinetics owing to the decoration of TiO2 nanosheets and the formation of interconnected structures. This study provides a favorable route for effectively improving the PEC activity of hematite photoanode, and also promotes the application of Ti3C2 MXene in solar water splitting.