Surfactant mediated synthesis of spherical binary oxides photocatalyst with enhanced activity in visible light

Spherical silica and zirconia mixed titania and pure titania samples were prepared in presence of
cetyltrimethylammonium bromide (CTAB) through controlled hydrolysis of corresponding metal alcoxides.
Effect of surfactant amount and calcinations temperature on morphology, surface area and photocatalytic
activity is studied using PXRD, SEM, FTIR, Solid state UV–vis spectroscopy and BET surface area. It is well
observed that in presence of 2 mol% CTAB, uniform sized spherical oxide particles can be synthesized.
However, increasing or decreasing the surfactant amount does not favor the spherical particle formation.
Material synthesis in presence of CTAB not only helps in the spherical particle formation but also
increases the surface area and visible light absorption. Studies on photocatalytic lead removal with
respect to calcination temperature indicate that the calcination at 500 ◦C is most suitable for the best
photocatalytic activity. Mixing of zirconia and silica helps in anatase phase stabilization even at 900◦C
calcination. Accordingly low decrease in surface area even at 900◦C calcination is observed. Due to
the phase stabilization and higher surface area binary oxide materials showed comparatively better
photocatalytic activity even after calcination at 900◦C. So it can be concluded that present synthesis
approach can produce uniform sized spherical binary oxide materials with better photocatalytic activity
in visible light.