Abstract
•A generic process has been developed for fabricating metal stannate nanostructures by simple substitution solution reactions followed by post-thermal treatments.•Band energy alignment, high carrier mobility and large specific surface area are found to play key roles for the enabled high efficiency in stannate nanostructured photocatalysts.•The developed process can be easily extended to the fabrication of other complex metal oxide nanostructures.
A variety of stannate nanostructures have been fabricated for UV photocatalysis, including zinc- and cadmium-based stannates. As the template nanostructures, high surface-area mesoporous metal hydroxystannate [ZnSn(OH)6 and CdSn(OH)6] nanoparticles (>100m2/g) have been synthesized using a simple, low-temperature substitution chemical process with controlled porosity, morphology and crystallinity. Post-synthetic thermal treatments were employed to obtain amorphous ZnSnO3, CdSnO3, ilmenite CdSnO3, and crystalline Zn2SnO4–SnO2 nanoparticles. As a result, the band gaps can be tuned from 5.4eV to 3.3eV and from 4.9eV to 2.1eV for Zn-based and Cd-based stannates, respectively. Amorphous ZnSnO3 porous nanoparticles showed highest activity toward dye degradation under UV illumination followed by the Zn2SnO4-SnO2 and ilmenite CdSnO3 nanostructures due to their beneficial band structure alignment, high conductivities, and high specific surface areas. This study may provide an important strategy for high throughput synthesis and screening of functional complex metal oxide nanomaterials, while the enabled stannate nanomaterials could be utilized in various applications.