低温湿式化学法制备ZnO纳米棒阵列膜及其光催化活性研究

采用一種簡單的低溫濕式化學方法,即將預處理好的鋅片直接放入5%甲酰胺水溶液中,在65℃烘箱中加熱24 h,在鋅片基底上成功制備出了大面積具有良好取向的ZnO納米棒陣列.用XRD、SEM、DRS、PL等測試手段對其進行了表征.研究結果表明,ZnO納米棒是六方釬鋅礦晶,與基底垂直,具有沿(002)晶面擇優生長的特征.另外,該陣列薄膜在379 nm附近發出強熒光,禁帶寬度為Eg=3.28 eV.以自鎮流高壓汞燈為光源、以ZnO納米棒為催化劑處理水中的甲基橙.結果顯示,ZnO納米棒的光催化反應為一級反應,表觀速率常數與甲基橙的初始濃度有關. ZnO films made of nanorod arrays with (002) crystal face orientation were prepared by a low-temperature wet-chemical method on a zinc metal substrate.X-ray diffraction (XRD) , Scanning Electron Microscopy (SEM) , UV-vis diffuse reflection and Photoluminescence (PL) were used to characterize the ZnO nanorod arrays.Photo-degradation of methyl orange in aqueous solution was investigated using the ZnO nanorods as a photocatalyst and a fluorescent high pressure mercury lamp as the light source.The results show that the ZnO nanorods are hexagonal wurtzite structures with highly oriented ZnO (002) crystal faces, which indicates that the as-prepared films were highly c-axis oriented.The room temperature photoluminescence of the as-prepared ZnO films exhibits a strong UV emission centered on 379 nm and a weak emission at about 450 nm.The photocatalytic reaction follows first-order reaction kinetics and the apparent rate constant is related to the initial concentration of methyl orange.