Effect of synthesis parameters on the structural characteristics and photocatalytic activity of ZnO

This paper describes the development of crystalline ZnO particles by a chemical route, using three different precursor salts (zinc acetate, zinc sulfate and zinc nitrate) and two different synthesis methods: precipitation and citrate method. This study aimed to shed light on how the precursor salts and synthesis method affect the photocatalytic activity of the zinc oxide. Rhodamine B (RhB) degradation was used as a probe reaction to test the as-synthesized ZnO photoactivity. It was observed that crystallinity and surface availability, which is related to the presence of synthesis residues, are the key parameters to determine photoactivity. On the other hand, surface area, agglomeration and sintering degree, which are indeed affected by synthesis route and counterions, do not play any important role on it. Precipitation method appeared to be the most suitable for the synthesis aiming photodegradation. Regarding the sample features, crystallinity becomes the most relevant factor to explain the photoactivity of the samples.

► ZnO particles were produced using different precursor salts and two different routes.
► Effect of counterions on ZnO morphology and photocatalytic activity was studied.
► Poisoning surfaces, which the presence of synthesis residues, affect photocatalysis.
► Crystallinity of ZnO particles affect photocatalytic activity.