Tin oxide nanocrystals embedded in nanopore arrays on stainless steel surface for photocatalytic applications

The immobilization of SnO₂ nanocrystals on solid substrates for practical photocatalytic applications suffers from poor adhesion that will lead to loss of photocatalytic activity and short service life. An efficient hydrothermal synthesis of SnO₂ nanocrystals embedded in nanopore arrays on stainless steel surface was presented in this paper. The morphology, chemical composition and microstructure of the embedded tin oxide nanocrystals were investigated by X-ray diffraction, field-emission scanning electron microscope, X-ray photoelectron spectroscopy and UV-visible diffuse reflectance spectroscopy. The photocatalytic activity and stability of SnO₂ nanocrystals was evaluated by photodegradation of methylene blue. SnO₂ nanocrystals embedded in nanopore arrays on stainless steel surface existed in a tetragonal rutile structure. The increasing of the hydrothermal temperature will lead to the improvement in photocatalytic activity of SnO₂ nanocrystals. The SnO₂ nanocrystals prepared at 220 °C performed the highest photocatalytic activity and good photocatalytic stability, indicating the effective immobilization of SnO₂ nanocrystals on anodized stainless steel.