不同缓冲层水热生长ZnO及其光催化性能

Hydrothermal Growth of Zinc Oxide on Different Buffer Layers and Its Photocatalytic Performance

采用低温水热法在氧化铟锡(ITO)和石墨烯(GR)分别覆盖的聚对苯二甲酸乙二醇酯(PET)柔性衬底上制备了ZnO纳米棒阵列。通过X射线光电子能谱表征了生长ZnO的籽晶层的元素种类及其化合价态,揭示溅射籽晶层的机理;通过X射线衍射和场发射扫描电子显微镜分别表征了两种样品的物相结构和微观形貌;通过光致发光光谱和电化学阻抗分别表征了其光、电性能;通过对亚甲基蓝的降解来表征其光催化性能。结果表明,在PET-ITO上生长的ZnO晶体具有更好的结晶度,但在PET-GR上制备的ZnO薄膜更加均匀致密,界面电阻较小,光生电子-空穴对的复合率较低。并且GR与ZnO纳米棒呈p-n异质结特性,有助于光生电子-空穴对的分离,从而表现出更优的光电性能。同时GR的芳环结构和π电子结构能有效吸附有机污染物分子,有助于提高其光催化性能。这使得PET-GR生长ZnO在60 min光催化降解亚甲基蓝溶液的降解率明显提高,达到90.5%。

Zinc oxide nanorod arrays were prepared on flexible polyethylene terephthalate substrates covered with indium tin oxide(ITO) and graphene(GR) via low-temperature hydrothermal method. X-ray photoelectron spectroscopy was used to characterize the element types and their chemical valence states of the seed layer of the growing zinc oxide, revealing the mechanism of sputtering the seed layer. X-ray diffraction and field emission scanning electron microscopy respectively characterized the phase structure and microscopic morphology of the two samples. Besides, the photoluminescence spectroscopy and electrochemical impedance respectively showed their optical and electrical properties. By degrading methylene blue, it showed its photocatalytic capability. The results demonstrate that the zinc oxide crystals grown on PETITO had better crystallinity, but the zinc oxide films prepared on PET-GR were more uniform and denser,with lower interface resistance, and the recombination rate of photogenerated electron-hole pairs was low.Furthermore, GR and zinc oxide nanorods exhibited p-n heterojunction characteristics, which contributed to facilitating the separation of photogenerated electron-hole pairs, thereby exhibited better photoelectric performance. Meanwhile, the aromatic ring structure and π electronic structure of GR could effectively adsorb organic pollutant molecules, which was conducive to improve its photocatalytic performance. This made the degradation rate of PET-GR growing zinc oxide photocatalytically degraded methylene blue solution significantly increased within 60 minutes, reaching 90.5%.