Photocatalytic production of superoxide ion in the aqueous suspensions of two kinds of ZnO under simulated solar light

Photocatalytic production of superoxide ion in the suspensions of tetrapod-like ZnO whisker (t ZnO) or nanosized ZnO particles (n-ZnO) under simulated solar light was quantitatively studied The yield of superoxide ion in suspension of t-ZnO with smaller specific surface area is much higher than that of n-ZnO This indicates that the specific surface area generally regarded as a key factor affecting photocatalytic activity does not play a critical role in generating superoxide ion The difference in the production of superoxide ion from t-ZnO and n-ZnO is mainly attributed to the smaller microstrain less defects and special surface properties of t-ZnO (C) 2010 Elsevier B V All rights reserved