Kuo Chi-Liang, Kuo Tz-Jun, Huang Michael H
Department of Chemistry, National Tsing Hua University, Hsinchu 30013, Taiwan.
J Phys Chem B. 2005 Nov 3;109(43):20115-21. doi: 10.1021/jp0528919.
Unusual ZnO microspheres constructed of interconnected sheetlike nanostructures were prepared by the hydrothermal synthesis approach. These microspheres possess high surface areas (28.9 m(2)/g) and are amorphous. Trisodium citrate plays a key role in directing the formation of these microstructures. By increasing the reaction time, these microspheres gradually dissolved to form short hexagonal microrods with stacked nanoplate or nanosheet structure. The microrods were also formed under the influence of trisodium citrate. They are crystalline and show a strong (002) X-ray diffraction peak of wurtzite ZnO structure. Both microsphere and microrod samples show near-band-edge emission at approximately 385 nm, but only the microrod sample exhibits yellow luminescence at approximately 560 nm. Due to their high surface areas, these ZnO microstructures were examined for their ability to photodecompose phenol. The as-prepared samples did not display photocatalytic activity due to possible surface adsorption of solution species. However, microspheres with heat treatment to 300 degrees C can substantially enhance the photodecomposition of phenol under direct sunlight irradiation and still maintain their high surface area nanosheet structure.
采用水热合成法制备了由相互连接的片状纳米结构构成的特殊氧化锌微球。这些微球具有高比表面积（28.9 m²/g）且为非晶态。柠檬酸钠在引导这些微观结构的形成过程中起关键作用。通过延长反应时间，这些微球逐渐溶解形成具有堆叠纳米板或纳米片结构的短六方微棒。微棒也是在柠檬酸钠的影响下形成的。它们是晶体，显示出纤锌矿型氧化锌结构的强（002）X射线衍射峰。微球和微棒样品在约385 nm处均显示近带边发射，但只有微棒样品在约560 nm处呈现黄色发光。由于其高比表面积，对这些氧化锌微观结构进行了光催化分解苯酚能力的研究。由于溶液物种可能在表面吸附，所制备的样品未表现出光催化活性。然而，经300℃热处理的微球在阳光直射下能显著增强苯酚的光分解，且仍保持其高比表面积纳米片结构。
