Liberating photocarriers in mesoporous single-crystalline SrTaO2N for efficient solar water splitting

Porous single-crystalline SrTaO2N, combining structural homogeneity and high porosity, afford a great promise as an active photocatalyst. The lack of grain boundaries in SrTaO2N porous single crystals (PSCs) enables fast photocarrier migration from bulk to the surface whilst the high porosity offers adequate accessible surface to perform photocatalytic reactions. In this work, we demonstrate a facile synthesis of SrTaO2N PSCs via a top-otactic conversion route. These SrTaO2N PSCs deliver exceptional activity and stability for photocatalytic O-2 production from water with a record-breaking apparent quantum efficiency as high as 17.9% at 420 +/- 20 nm. Overall water splitting with H-2/O-2 equals 2 has also been attained in a Z-scheme system employing SrTaO2N PSCs as the O-2-evolution moiety. These results signify a paradigm to improve photocatalytic performance based on PSCs, which extends the toolbox to achieve efficient solar water splitting over conventional photocatalysts.

Automated summary

The study demonstrates the exceptional activity and stability of porous single-crystalline SrTaO2N in photocatalytic oxygen production, achieving a record-breaking apparent quantum efficiency. Water splitting with a hydrogen/oxygen ratio of 2 has been accomplished in a Z-scheme system using SrTaO2N as the oxygen-evolution component. These results indicate a paradigm shift in improving photocatalytic performance and expanding the toolbox for efficient solar water splitting.