Zn-Al2O3 Composites with High Aluminum Content and Nanostructured Al2O3/ZnO Prepared by Electrochemical Technique from Non-Suspended Solution

Zn-Al2O3 composites were electrodeposited from a non -suspended solution containing ZnSO4 center dot 7H(2)O and Al-2(SO4)(3)center dot 14-18H(2)O using benzyldimethyltetradecylammonium chloride dehydrate (BDTAC) as the additive at an electrodeposition current of 50-500A/m(2) with an air or a nitrogen bubbling. Initial layers with a thickness of approximately 1 mu m were observed in the Zn-Al2O3 composite on copper substrates. Furthermore, the Zn-Al2O3 composite was composed of two different crystallographic areas, namely, nano -level size deposited grains with 20-60 nm in width and 100-200 nm in length, and closely packed fine particle deposits with a diameter of approximately 5 nm containing more than 26 atomic% aluminum. The nano -level size deposited grains and the closely packed fine particle deposits comprised nano -size ZnO and theta-Al2O3, respectively. The oxygen concentration in Zn-Al2O3 composite by the air bubbling was higher than that in Zn-Al2O3 composite by the nitrogen bubbling. In contrast, the zinc content ratio in Zn-Al2O3 composite by the air bubbling was lower than that in Zn-Al2O3 composite by the nitrogen bubbling. The aluminum concentration in closely packed fine particle deposits in Zn-Al2O3 composite by the air bubbling was almost the same value as that in Zn-Al2O3 composite by the nitrogen bubbling. (C) The Electrochemical Society of Japan, All rights reserved.