Metallic Zinc Nanowires Effect in High-Performance Photoresponsive and Photocatalytic Properties of Composite Zinc Stannate Nanowires

Abstract

High-performance photocatalytic and photoresponsive properties have been made from composite ZnSnO3 nanowires. The composite nanowires consist of several phases, such as a major phase of ZnSnO3 and second phases of ZnO, SnO2, and metallic Zn nanowires. These nanowires formed many nanowire-to-nanowire junctions at the networking points of the ZnO/ZnSnO3/SnO2 interfaces; thus, a heterojunction cascade is obtained in the presence of these semiconductors. A charge transfer takes place at the composite nanowires under UV-light (λ ∼ 365 nm, I = 2.33 mWcm−2), and the Zn nanowires subsequently act as effective electron collectors, resulting in an extremely high photocurrent under an Ohmic contact electrode. The photoelectric current of the composite ZnSnO3 nanowires exhibited a rapid photoresponse of ∼1 sec upon irradiation by UV light. An extremely high photo-current to dark-current ratio is 2.7 × 105%. The composite nanowires exhibited an extremely high photodegradation ratio of ∼66% within 30 minutes under UV-light irradiation. Photocatalysts of composite ZnSnO3 nanowires were found to be superior to those made from composite ZnO-SnO2, ZnO, and SnO2 nanowires. The ZnSnO3 nanowires successfully acted as key components of the photoexcited separation and migration of the generated charges with a low recombination rate.