A full compositional range for a (Ga1-x Zn x )(N1-x O x ) nanostructure: high efficiency for overall water splitting and optical properties.

ABSTRACT

Bulk (Ga1-x Zn x )(N1-x O x ) as a photocatalyst has received increasing attention as a potential solution for the energy shortage challenge; however, its catalytic performance is highly limited by its bulk form. To improve the photochemical potential, the nanoscale form of this multiple-metal oxynitrides is desirable. In this work, a new type of (Ga1-x Zn x )(N1-x O x ) nanostructure is obtained. Its composition can tuned to the full range (0.18 < x < 0.95). The (Ga1-x Zn x )(N1-x O x ) nanostructure exhibits excellent photocatalytic activity for overall water splitting, and the highest quantum efficiency of (Ga1-x Zn x )(N1-x O x ) is as high as 17.3% under visible light irradiation. Using this new type of (Ga1-x Zn x )(N1-x O x ) nanostructure, the narrowing of the bandgap for (Ga1-x Zn x )(N1-x O x ) is not only due to an increase in the valence band maximum, but it is also related to a decrease in the conduction band minimum.