Na/Mo co-doped PbTiO for photocatalytic water oxidation and Z-scheme overall water splitting under visible light.

Herein, we demonstrate a sodium/molybdenum (Na/Mo) co-doped ferroelectric PbTiO for efficient photocatalysis under visible light. Doped with a high concentration of Mo, quasi-continuous new energy levels are successfully introduced below the conduction band minimum of PbTiO, giving rise to a band-to-band redshift of the absorption edge. The valence state difference of Mo and Ti in the doped PbTiO is compensated by the Na dopant, thus effectively suppressing the formation of the recombination centres caused by Mo. Combined with the intrinsic built-in electric field in PbTiO, this Na/Mo co-doping strategy enables PbTiO to exhibit superior water oxidation activity under visible light with threshold wavelength up to 550 nm, which also promotes overall water splitting under visible light in a Z-scheme photocatalytic system. This strategy provides a generally applicable solution to extend the visible light absorption spectrum and engineer electronic structures of ferroelectric materials for photocatalysis and other energy conversion applications.