Ternary composite of TiO nanotubes/Ti plates modified by g-CN and SnO with enhanced photocatalytic activity for enhancing antibacterial and photocatalytic activity.

A series of g-CN-SnO/TiO nanotubes/Ti plates were fabricated via simple dipping of TiO nanotubes/Ti in a solution containing SnCl and g-CN nanosheets and finally annealing of the plates. Synthesized plates were characterized by various techniques. The SEM analysis revealed that the g-CN-SnO nanosheets with high physical stability have been successfully deposited onto the surface of TiO nanotubes/Ti plate. Photocatalytic activity was investigated using two probe chemical reactions: oxidative decomposition of acetic acid and oxidation of 2-propanol under irradiation. Antibacterial activities for Escherichia coli (E. coli) bacteria were also investigated in dark and under UV/Vis illuminations. Detailed characterization and results of photocatalytic and antibacterial activity tests revealed that semiconductor coupling significantly affected the photocatalyst properties synthesized and hence their photocatalytic and antibacterial activities. Modification of TiO nanotubes/Ti plates with g-CN-SnO deposits resulted in enhanced photocatalytic activities in both chemical and microbial systems. The g-CN-SnO/TiO nanotubes/Ti plate exhibited the highest photocatalytic and antibacterial activity, probably due to the heterojunction between g-CN-SnO and TiO nanotubes/Ti in the ternary composite plate and thus lower electron/hole recombination rate. Based on the obtained results, a photocatalytic and an antibacterial mechanism for the degradation of E. coli bacteria and chemical pollutants over g-CN-SnO/TiO nanotubes/Ti plate were proposed and discussed.