A single-crystalline particulate BaTaO2N photocatalyst that is active in overall water splitting under visible light up to 640 nm is developed by coloading Cr2O3/Na-Rh and IrO2 cocatalysts to promote H2 and O2 evolution reactions, respectively, and combining RbCl flux-assisted nitridation with Mg doping to promote charge transfer to the cocatalysts.
