Amino Acid-Assisted Hydrothermal Synthesis and Photocatalysis of SnO2 Nanocrystals

It is still a major challenge for preparing semiconductor nanocrysals with controllable size, shape, and doping, Especially, the size of nanoparticles under 10 nm still remains a big challenge. To date, there are very few researches of the synthesis of SnO2 nanocrystals by using biomolecule-assisted hydrothermal approach. SnO2 is an n-type semiconductor with the free exciton Bohr radius of 2.7 nm. The degradation of rhodamine B (RhB), an organic dye, in aqueous suspension is selected as a probe reaction to evaluate the catalytic activity of semiconductor photocatalytic performance. Herein, we report a biomolecule-assisted hydrothermal route for generating SnO2 with diameters < 10 nm, which presents excellent photocatalytic degradation of RhB. Under the basic condition, the degradation of RhB is close to 100% within 150 min. The high degradation rate of RhB on the as-synthesized SnO2 nanocrystals can be attributed to the small size. The degradation mechanism is also discussed.