Pore walls as high-way for efficient bulk charge transfer in porous SrTiO 3 single crystals boosting photocatalytic overall water splitting

Suppressing carrier recombination in bulk and facilitating carrier transfer to surface via rational structure design is of great significance to improve solar -to -H 2 conversion efficiency. We demonstrate a facile hydrothermal method to synthesize porous SrTiO 3 single crystals (SrTiO 3 -P) with exposed (001) facets by introducing carbon spheres as templates. The obviously increased surface photovoltage and photocurrent response indicate that the interconnected pore walls act as enormous charge transfer "highways ", accelerating carrier transport from bulk to surface. Furthermore, the absence of grain boundaries and high crystallinity could also lower the carrier recombination rate. Thus, the SrTiO 3 -P photocatalyst loaded with Rh/Cr 2 O 3 as cocatalyst exhibits 1.5 times higher overall water splitting activity than that of solid SrTiO 3 , with gas evolution rate of 19.99 mu mol h -1 50 mg - 1 for H 2 and 11.37 mu mol h -1 50 mg - 1 for O 2 . Additionally, SrTiO 3 -P also shows superior stability without any decay during cycling testing. This work provides a new insight into designing efficient multicomponent photocatalysts with a single -crystal porous structure.