Wenguang Tu1,2, Yong Zhou1,3,2, Qi Liu4,1,5, Zhongping Tian1,2, Jun Gao1,2, Xiaoyu Chen4,2, Haitao Zhang6, Jianguo Liu4,1,3, Zhigang Zou4,1,3,2
1Eco-materials and Renewable Energy Research Center (ERERC), Nanjing University, Nanjing 210093, P.R. China
2School of Physics, Nanjing University, Nanjing 210093, P. R. China
3National Laboratory of Solid State Microstructures, Nanjing University, Nanjing 210093, P.R. China
4Department of Materials Science and Engineering, Nanjing University, Nanjing 210093, P. R. China
5School of Mechanical and Automotive Engineering, Anhui Polytechnic University, Wuhu 241000, P. R. China
6CAS Key Lab of Green Process & Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing100190, P. R. China
Tóm tắt
AbstractRobust hollow spheres consisting of molecular‐scale alternating titania (Ti0.91O2) nanosheets and graphene (G) nanosheets are successfully fabricated by a layer‐by‐layer assembly technique with polymer beads as sacrificial templates using a microwave irradiation technique to simultaneously remove the template and reduce graphene oxide into graphene. The molecular scale, 2D contact of Ti0.91O2 nanosheets and G nanosheets in the hollow spheres is distinctly different from the prevenient G‐based TiO2 nanocomposites prepared by simple integration of TiO2 and G nanosheets. The nine times increase of the photocatalytic activity of G‐Ti0.91O2 hollow spheres relative to commercial P25 TiO2 is confirmed with photoreduction of CO2 into renewable fuels (CO and CH4). The large enhancement in the photocatalytic activity benefits from: 1) the ultrathin nature of Ti0.91O2 nanosheets allowing charge carriers to move rapidly onto the surface to participate in the photoreduction reaction; 2) the sufficiently compact stacking of ultrathin Ti0.91O2 nanosheets with G nanosheets allowing the photogenerated electron to transfer fast from the Ti0.91O2 nanosheets to G to enhance lifetime of the charge carriers; and 3) the hollow structure potentially acting as a photon trap‐well to allow the multiscattering of incident light for the enhancement of light absorption.
