ABSTRACT
Figure 6.1 shows schematically the configuration of a ZnO nanowire array EC cell. The ZnO nanowire array was hydrothermally prepared using the procedures reported elsewhere.19 In brief, ITO glass (2 × 2 cm) was first immersed in an 80 mL 5 mM zinc acetate aqueous solution with a small amount of ammonia (28%, Wako Chemicals, 0-5 mL) in a bottle with autoclavable screw cap, and then the solution was kept at 95°C for 12 h with the solution refreshed every
3 h. Before the growth, a thin layer of ZnO film with the thickness of about 5 nm was sputtered on the ITO substrate as the seed layer. After reaction, a uniform ZnO nanowire array covering ITO glass was obtained. To fabricate the EC cell, ZnO nanowires grown at the edge of the substrate were removed using HCl (10%) leaving an area of 1 cm × 1 cm covered with a ZnO nanowire array.
