【摘要】 采用简单的水热法制备了比表面积高达7.9801m²/g的ZnO微米星状结构（ZnO star）,利用AgNO₃紫外光照还原反应在其表面附着Ag纳米颗粒,构成Ag@ZnO star微-纳米复合分型结构,其光学吸收波长尺度涵盖从近紫外至近红外的太阳光谱波段.用X射线衍射光谱（XRD）、X射线光电子能谱（XPS）等测定了样品的相结构和组成元素.用扫描电子显微镜（SEM）、透射电子显微镜（TEM）以及高分辨透射电子显微镜（HRTEM）确定了所合成样品的形貌和晶面结构并且证实了Ag@ZnO star异质结构的存在.紫外-可见-近红外分光光度计（UV-VIS-NIR spectrophotometer,UVNS）测试显示样品在近紫外至近红外波段都具有良好的光吸收性能.用Labsolar-6A高气密性自动在线光催化分析系统测量了样品的CO₂光催化还原为CO的性能,结果表明Ag@ZnOstar微-纳复合结构显著地提高了CO₂光催化还原的能力,较商用ZnO粉末提高了4倍,其原因归于两点:一是ZnO的分型结构显著提高了比表面积,二是Ag粒子与ZnO的耦合产生的等离激元增强效应以及使非极性面的活性得到增强.此工作对高效微-纳复合结构CO₂光催化还原剂的构建具有重要的指导意义.更多还原

【Abstract】 This paper reports that a simple hydrothermal method was used to synthesize the crystalline zinc oxide micron-nano fractal star structure with the specific surface area of up to 7.9801 m²/g,and the silver nanoparticles were grown on the surface of the zinc oxide by silver nitrate reduction method,which constituted the Ag@ZnO configuration.Its scale ranges from near-ultraviolet（NUV）to near-infrared（NIR）solar spectral bands.The morphology and crystal phase were characterized by scanning electron microscopy（SEM）,transmission electron microscopy（TEM）, high resolution transmission electron microscopy（HRTEM）, X-ray photoelectron spectroscopy（XPS）and X-ray diffraction（XRD）.Measurement of the UV-visible-near infrared spectrophotometry shows that the sample has a good optical absorption performance ranged from NUV to NIR band.We mainly studied the properties of photocatalytic reduction of carbon dioxide with Labsolar-6 A（a high air tightness automatic online photocatalytic analysis system）.Compared to the commercial zinc oxide powder,the Ag@ZnO micron star structure shows about four time higher photocatalytic activity reduction of CO₂.The reason is attributed to two points:First,the type structure of ZnO significantly improves the specific surface area,and secondly,the plasmon enhancement effect due to the coupling of Ag particles and ZnO and the activity of the non-polar surface are enhanced.This work has important guiding significance for the construction of micro-nano composite CO₂ photocatalytic reduction catalysts.更多还原