• 文献标题:   Graphene-wrapped TiO2 nanofibers with effective interfacial coupling as ultrafast electron transfer bridges in novel photoanodes
  • 文献类型:   Article
  • 作  者:   DAI YQ, SUN YB, YAO J, LING DD, WANG YM, LONG H, WANG XT, LIN BP, ZENG TTH, SUN YM
  • 作者关键词:  
  • 出版物名称:   JOURNAL OF MATERIALS CHEMISTRY A
  • ISSN:   2050-7488 EI 2050-7496
  • 通讯作者地址:   Southeast Univ
  • 被引频次:   49
  • DOI:   10.1039/c3ta13399k
  • 出版年:   2014

▎ 摘  要

For TiO2-based photoanodes, the interfacial coupling between TiO2 and conductive materials (e.g., carbon) plays a vital role in determining the electron transfer efficiency and thus photoelectrical performance. In this paper, we describe a facile approach to effectively engineering the interfacial coupling between reduced graphene oxide (RGO) and TiO2 in well-designed one-dimensional (1D) RGO-wrapped TiO2 nanofibers, which act as ultrafast electron transfer bridges when implanted in photoanodes. The 3-5 nm RGO nanoshells were hybridized with TiO2 nanofibers as an electron donor component via d-pi electron orbital overlap between C and Ti atoms, by adopting a thermal reduction at 450 degrees C. Remarkable photoelectric improvement, in terms of high photocurrent density by 2.2-fold and ultralow charge transfer resistance (R-ct) by 0.2-fold, is ascribed to the interfacial charge transfer. Completely reduced RGO in RGO/TiO2 nanofibers was not necessary at the expense of their hydrophilicity, as it led to unexpected isolation in the photoanodes. The thermal reduction temperature of RGO/TiO2 nanofibers was found to be critical, and a maximal photocurrent density could be achieved by 2.7-fold at 530 degrees C. An excess of RGO/TiO2 nanofibers of more than 5 wt% had a degrading effect on the photoelectrical activity, largely due to the light-block effect and isolation in the matrix. This strategy provides new insight for tuning the intrinsic chemical and/or physical properties of well-designed semiconductor nanostructures with promising photoactivities in highly efficient photovoltaic devices.