Fast and clean preparation of highly crystalline SnO2 nanoparticles incorporated in amorphous carbon, and its dye removal performance

The thermal oxidation of molten SnCl 2 leads to the formation of SnO 2 nanocrystals of less than 50 nm in diameter at 600 °C. These nanoparticles grow to large crystals with sizes of up to 10 µm by increasing the heat-treatment temperature to 800 °C. The excessive growth of SnO 2 crystals can be prevented by the introduction of polyethylene terephthalate (PET) and inorganic salts, through which SnO 2 @carbon nanocomposites could be prepared in a fast and clean way. Increasing the heat-treatment temperature from 600 to 800 °C leads to the enhancement of the crystalline quality of SnO 2 present in the nanocomposites, while the excessive crystal growth at high temperatures is prevented. A large number of highly-crystalline SnO 2 nanocrystals with sizes of less than 5 nm embedded in carbon substrate could be detected in the nanocomposite material prepared at 800 °C. The prepared sample exhibits an interesting combination of dye adsorption, with the capacity of 63 mg dye /g nanocomposite , as well as photocatalytic performance under normal sunlight irradiation toward the removal of methylene blue. This article suggests a clean and fast strategy for the preparation of highly crystalline SnO 2 - amorphous carbon nanocomposites.