Guo L Q, Hu Y W, Yu B, Davis E, Irvin R, Yan X G, Li D Y
Department of Chemical and Materials Engineering, University of Alberta, Edmonton, AB T6G 2V4, Canada.
Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta, Canada.
Sci Rep. 2016 Feb 26;6:22247. doi: 10.1038/srep22247.
Titanium dioxide (TiO2) nanotubes are promising for a wide variety of potential applications in energy, biomedical and environmental sectors. However, their low mechanical strength and wide band gap limit their widespread technological use. This article reports our recent efforts to increase the mechanical strength of TiO2 nanotubes with lowered band gap by immobilizing a peptide of D-amino K122-4 (D) onto the nanotubes. Topographies and chemical compositions of the peptide-coated and uncoated TiO2 nanotubular arrays were characterized by scanning electron microscopy and X-ray photoelectron spectroscopy (XPS). Properties of the peptide-coated and uncoated TiO2 nanotubular arrays, including hardness, elastic modulus, electron work function and photocurrent, were evaluated using micromechanical probe, Kelvin Probe and electrochemical system. Effect of the peptide on surface conductivity was also investigated through current mapping and I-V curve analysis with conductive atomic force microscopy. It is demonstrated that the peptide coating simultaneously enhances the mechanical strength, photocatalytic and electrical properties of TiO2 nanotubes.
二氧化钛（TiO₂）纳米管在能源、生物医学和环境领域有着广泛的潜在应用前景。然而，它们较低的机械强度和较宽的带隙限制了其在技术上的广泛应用。本文报道了我们最近通过将D-氨基K122-4（D）肽固定在纳米管上来提高TiO₂纳米管机械强度并降低其带隙的研究工作。通过扫描电子显微镜和X射线光电子能谱（XPS）对涂覆肽和未涂覆肽的TiO₂纳米管阵列的形貌和化学成分进行了表征。使用微机械探针、开尔文探针和电化学系统评估了涂覆肽和未涂覆肽的TiO₂纳米管阵列的性能，包括硬度、弹性模量、电子功函数和光电流。还通过导电原子力显微镜的电流映射和I-V曲线分析研究了肽对表面电导率的影响。结果表明，肽涂层同时提高了TiO₂纳米管的机械强度、光催化性能和电学性能。
