TiO2-SiO2 Janus particles with highly enhanced photocatalytic activity

Titania-silica (TiO2-SiO2) Janus particles with high photocatalytic activity were synthesized using a Pickering emulsion method. The Janus particles were calcined at two temperatures and the effect of the calcination temperature on photocatalysis was explored. Their morphology and structure were characterized. The photocatalytic activity of the calcined Janus particles was compared with that of calcined SiO2-TiO2 core-shell particles and commercially available P25 TiO2 nanoparticles. Janus particles calcined at 450 degrees C (Janus@450) showed significantly higher adsorption (by almost 2-14x) and rate of degradation (by almost 6.6-211x) of a photo-stable Solophenyl green dye compared to other TiO2 structures. The higher activity of Janus@450 was attributed to its unique electronic structure which showed a significantly higher average carrier lifetime of 1.98 ns compared to 0.18 ns of other structures.