Novel three-dimensionally ordered macroporous SrTiO3 photocatalysts with remarkably enhanced hydrogen production performance

Abstract

Three-dimensionally ordered macroporous SrTiO3 (3DOM-SrTiO3) materials with different pore sizes were originally prepared and employed as photocatalysts in the water splitting for hydrogen generation. These 3DOM-SrTiO3 photocatalysts were characterized by XRD, SEM, TEM, EDS, DR UV–vis and N2 sorption. Because of the slow photon effect of 3DOM-SrTiO3, notably enhanced efficiency of water splitting for hydrogen evolution was obtained compared with the solid-state SrTiO3 (SS-SrTiO3) and disordered porous SrTiO3 (Disorder-SrTiO3). The effect of stop-band on the efficiency of photocatalytic hydrogen production was studied by tuning the pore diameter of 3DOM-SrTiO3. It was found that higher hydrogen evolution efficiency could be achieved when the photonic stop-band of 3DOM-SrTiO3 was overlapped with its band gap, which was further confirmed by the control experiments under certain wavelength light irradiation. 3DOM-SrTiO3(270nm) exhibited the highest photocatalytic hydrogen evolution rate (up to 3599μmol/g·h), which was 31 times as high as that of SS-SrTiO3 and 11 times higher than that of Disorder-SrTiO3. Furthermore, these 3DOM-SrTiO3 catalysts were very stable and no obvious loss in photocatalytic efficiency of hydrogen production was observed after five cycles.