Comparison of photocatalytic activity of zinc stannate particles and zinc stannate/zinc oxide composites for the removal of phenol from water, and a study on the effect of pH on photocatalytic efficiency

Zinc stannate and composite zinc stannate/zinc oxide particles were synthesized by a precipitation method in aqueous media at room temperature. As synthesized particles were characterized by SEM, TEM and XRD. Photocatalytic degradation of 50 ppm phenol in water in the presence of as synthesized particles was studied using the fluorescence decay. Experiments were carried out in both acidic and basic conditions to assess the stability of the catalyst particles and the role of pH on the photocatalytic degradation efficiency. Composite material showed enhanced activity in slightly acidic conditions. Efficiency of photodegradation was observed to be closely related to the isoelectric point of zinc stannate/zinc oxide composites.