Improving photocatalytic efficiency over ZnO nanowire fabricated on (111)Ag

A special technique to control a texture orientation of silver (Ag) thin films via using gas-timing (GT) RF magnetron sputtering was investigated. By utilizing GT technique, a dense structure and a high ratio of (111)/(200) of Ag film could be obtained without any applying additional energy sources. The GT technique not only provides the ability to adjust the number of sputter species from the target, but also generates the self-energy assisted deposition which related to the atomic peening effect. Ag thin film with (111)/(200) ratio of 40 was used as a substrate to grow ZnO nanowires. Small lattice mismatch between ZnO and Ag and small roughness and grain size with high (111) crystalline of Ag would provide dense growth of ZnO nanowires. A heterojunction of between ZnO and Ag formed Shottky contacts to prolong the excitation life time of ZnO photocatalysis around 2-4 times, compared with ZnO nanowire/ZnO thin film and ZnO powder.