Photocatalytic Enhancement in ZnO-Ag2O Core-shell NanorodHeterostructure

• Main Authors: Tsai, Hung-Yi, 蔡虹驛
• Other Authors: Wu, Jenn-Ming
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/26877074227361567968

碩士 === 國立清華大學 === 材料科學工程學系 === 102 === Ag2O thin film, which possessed 2.42eV optical band gap, were deposited on glass and silicon substrates by RF magnetron sputtering using silver target under 25% oxygen flow ratios, 170°C substrate temperature, 50W sputtering power and 5 mTorr working pressure. The influence of oxygen flow ratio and substrate temperature on the structural, morphological, electrical, and optical properties of deposited Ag2O films was investigated. Increasing oxygen partial pressure during sputtering decreases the crystallinity of Ag2O due to oxidation of large portion of the metal target and re-sputtering effect. X-ray diffraction and X-ray photoelectron spectroscopy indicates that sputtering with higher oxygen partial pressure prefers to deposit silver oxide film with higher oxidation state, and sputtering at higher substrate temperature tend to demonstrate silver oxide film with lower oxidation state. Reactive-sputtered Ag2O was deposited on ZnO nanowires which were hydrothermally grown on conductive Zn0.99Ga0.01O film/ Si substrate. Absorption in the visible-NIR range of the ZnO-Ag2O core-shell heterostructure is investigated. Photodegradation of organic pollutants in aqueous solution is a promising application for this ZnO-Ag2O core-shell heterostructure, which exhibit a photodegradation rate 1.7 times higher than that recorded for the bare ZNA under sun irradiation.