A novel Zn2GeO4 superstructure for effective photocatalytic hydrogen generation

Crystal orientation-ordered hexagonal Zn2GeO4 nanorod-bundles have been obtained via a synergistic self-assembly route. Each nanorod unit of the bundles maintains its individual hexagonal rod-shaped structure and is dominated by (110) and ((1) over bar(1) over bar0) facets, and all of them are aligned parallel to the growth direction in a high density. An ordered self-assembly of anisotropic nanorods was suggested to elucidate the formation of the unique bundle structures. The novel structure of Zn2GeO4 bundles assembled from hexagonal nanorods leads to a surprisingly high UV-light-driven activity for the photocatalytic decomposition of water-methanol solution to hydrogen. The correlation of structure and photocatalytic activity of the ordered nanorod-bundles was discussed, indicating a new strategy of bundling Zn2GeO4 nanorods with reactive facets to effectively enhance photocatalytic activities of 1-D nanostructures.