3DOM-SrTiO3 photocatalysts with different pore sizes are firstly prepared.
The highest H2 production rate is obtained compared with reported SrTiO3 catalysts.
H2 evolution rate of 3DOM-SrTiO3(270 nm) is 31 times as high as that of SS-SrTiO3.
The notably enhanced activity is attributed to the slow photon effect of 3DOM-SrTiO3.
3DOM-SrTiO3 catalysts exhibit excellent durability in solar water splitting reaction.