Tailoring the active surface sites of ZnO nanorods on the glass substrate for photocatalytic activity enhancement

Abstract

Abstract The urgent need for inexpensive, efficient, ease in use and reusable photocatalyst has attracted the attention of many researchers. Here, the photocatalyst ZnO nanorods were synthesized with a simple, low cost and rapid ultrasonic spray pyrolysis method and then grown with a hydrothermal method for 2, 4, 6 and 8\u202fh. The ZnO nanorods grown for 6\u202fh shows the highest photocatalytic efficiency although do not have the largest surface area. This is probably due to its surface is dominated by (002) facets as indicated by the highest texture coefficient (TC) value. The (002) polar facets consisting of a positive Zn-terminated (002) facets and a negative O-terminated (00-2) facets may play an important role in more efficient UV absorption and photogenerated charges separation. Moreover, the highest crystallite size as shown in XRD result provide pathways for electrons and holes for redox reactions on the surface of ZnO nanorods. The synthesized ZnO nanorods also contain high concentration of oxygen interstitial as a source of holes that react with the OH− ions that easily adsorbed on (002) facets.