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 H-2. 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 {10 (1) over bar0} to semipolar {10 (1) over bar1} and then finally to mixed {10 (1) over bar1} and polar {000 (1) over bar} by carefully controlling the growth temperature and nitridation time. Correspondingly, the ZnO content in the GaN lattice can be achieved in the range of similar to 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 H-2 production under visible-light irradiation.