Solubility and crystallographic facet tailoring of (GaN)(1-x)(ZnO)(x) pseudobinary solid-solution nanostructures as promising photocatalysts.

(GaN)1-x(ZnO)x solid-solution nanostructures with superior crystallinity, large surface areas and visible light absorption have been regarded as promising photocatalysts for overall water splitting to produce H2. In this work, we report the preparation of (GaN)1-x(ZnO)x solid-solution nanorods with a high ZnO solubility up to 95% via a two-step synthetic route, which starts from a sol-gel reaction and follows with a nitridation process. Moreover, we clearly demonstrated that the crystallographic facets of (GaN)1-x(ZnO)x solid-solution nanorods can be finely tailored from non-polar {10̄10} to semipolar {10̄11} and then finally to mixed {10̄1} and polar {000̄1} by carefully controlling the growth temperature and nitridation time. Correspondingly, the ZnO content in the GaN lattice can be achieved in the range of ∼25%-95%. Room-temperature cathodoluminescence (CL) measurements on the three types of (GaN)1-x(ZnO)x solid-solution nanorods indicate that the minimum band-gap of 2.46 eV of the solid-solution nanorods is achieved under a ZnO solubility of 25%. The efficiency and versatility of our strategy in the band-gap and facet engineering of (GaN)1-x(ZnO)x solid-solution nanorods will enhance their promising photocatalytic utilizations like an overall water splitting for H2 production under visible-light irradiation.