中文摘要：

以月季花花瓣为模板,经钛盐溶液浸渍后煅烧,合成了新型TiO2分层介孔纳米片.采用X射线衍射（XRD）、场发射扫描电子显微镜（FESEM）、环境扫描电子显微镜（ESEM）、透射电子显微镜（TEM）、紫外-可见漫反射光谱（UV-Vis/DRS）和氮气吸附-脱附曲线分析等手段对样品进行了表征.结果表明,所得样品由厚度约4 nm的具有生物形态结构的锐钛矿型TiO2纳米片组成.TiO2薄层表面存在大量介孔,其孔径集中分布于4 nm左右.由紫外-可见漫反射吸收光谱可知,材料的吸收边较纳米TiO2（P25）红移了约20 nm,因而具有更高的可见光光催化活性.TiO2分层介孔纳米片在阳光下表现出较强的光催化活性,在90 min内对亚甲基蓝的降解率可达98%,远高于TiO2纳米粉.

英文摘要：

Hierarchical mesoporous TiO2 nanosheets were prepared using China rose petal as biotemplate through facile infiltration and thermal decomposition.For characterization of texture,X-ray diffraction spectroscopy（XRD）,field emission scanning electron microscopy（FESEM）,transmission electron microscopy（TEM）,UV-Vis diffuse reflectance spectra（UV-Vis/DRS） and nitrogen adsorption-desorption measurements were adopted.The results demonstrate that the biomorphic structure of anatase TiO2 nanosheets with the thickness of ca.4 nm is obtained.There exist mesopores with pore size of about 4 nm on the surface of the TiO2 nanosheets.Hierarchical mesoporous TiO2 nanosheets exhibit a clear red shift（20 nm） comparing with Degussa P25,which could be excited by visible irradiation and enhance the visible activity.Hierarchical mesoporous TiO2 nanosheets display the superior photocatalytic activity for the degradation of methylene blue under sun-light irradiation,with a which degradation rate as high as 98%.