Controlled synthesis of SnO_2 nanostructures with different morphologies and the influence on photocatalysis properties

摘要

SnO_2 nanoparticles, nanoflowers, and nanorods of highly crystalline were synthesized via a simple hydrothermal method. The size and morphology of the SnO_2 nanostructures could be controlled by varying the NaOH concentration of the precursor solutions. The SnO_2 structures appeared to be sphere-like nanoparticles with diameters in the range of 5-10 nm in lower NaOH concentrations. In higher NaOH concentrations, the nanostructures showed orientation growth behavior and were flower-like or rod-like in morphology. The sphere-like shape demonstrated that Ostwald ripening took effect only at lower NaOH concentration while the preferential growth behavior at higher NaOH concentration testified "oriented attachment" was more suitable under this condition. Photocatalysis experiments were carried out to study the influence of the morphology, size, and surface on photocatalytic activities of SnO_2. The nanoparticles synthesized with the M_(NaOH) : M_(SnCl_4) =4:1 showed the highest photolytic activities owing to their tiny size, large surface area, and abundant defect-related energy states.