Fe2TiO5-incorporated hematite with surface P-modification for high-efficiency solar water splitting

Hematite is a promising photocatalyst for solar water splitting while its performance has been severely limited by various factors. Recently surface Fe 2 TiO 5 layer was widely reported to enhance the performance of hematite with a favorable band position to facilitate hole transport. Here we further show that the Fe 2 TiO 5 -incorporation in bulk hematite can also improve the performance with faster charge separation. Moreover, it can be well coupled with surface P-modification to simultaneously improve charge separation and hole transfer with a synergetic effect. The Ti and P co-modified hematite shows a significantly enhanced photocurrent of 2.37   mA/cm 2 at 1.23   V vs. RHE when compared to the pristine value of 0.85   mA/cm 2 . After coupling with Co-Pi catalysts, the hematite sample can even achieve a stable, high photocurrent of 2.90   mA/cm 2 at 1.23   V vs. RHE. The design of Ti and P co-modified hematite hollow nanostructures can be used as a promising candidate for solar water splitting applications. The discrete Fe 2 TiO 5 -incorporation also provides a good insight on the mechanism to understand other Ti-based treatments of hematite.