Carbonaceous nanostrucutres and their nanocomposites: Synthesis, properties and applications

Abstract

As a substance rich in carbon, carbonaceous nanostructures is a new class of carbon nanomaterials with properties that differ significantly from other forms of carbon , and shown potential application in the field of heavy metal sorption, catalytic, CO2 fixation , energy storage materials, and biomedicine. From the viewpoint of economic, environmental and societal issues , the hydrothermal carbonization (HTC) process form biomass presents superior characteristics that make it a promising route for the synthesis of these functional carbonaceous materials . In this thesis, a brief introduction of the relative research and a literature review on the carbonaceous nanostructures and their nanocomposites were presented in Chapter 2, the latest advances in the synthesis of functional carbonaceous materials from different biomasses or biomass derived sources via the HTC process will be outlined. Chapter 3 systematically described the preparation of monodispersed colloidal carbonaceous spheres (CCS) with different size by a facile twostep hydrothermal method. We demonstrated that the obtained monodispersed CCS can be controlled from 160 to 400 nm in diameter with a standard deviation no more than 8%. The success of this synthesis strongly depends on the accuracy control of the amount of seeds and monomers (glucose). In chapter 4 , high-quality carbonaceous nanotubes were prepared through one-pot hydrothermal process with well-controlled dimensions and high yield . The success of this method should first be attributed to the formation of silver@carbonaceous composites nanocables and then the etch removal of their silver core nanowires can be easily inspired by manipulating the dynamic equilibrium from growth to oxidative etching via controlling reaction temperature . To demonstrate the potential of carbonaceous nanomaterials for the biomedicine application, in chapter 5 and 6, successful synthesis of Carboncoated Au and Fe3O. nanocomposites were achieved respectively by modifying relative as-prepared nanoparticles with polymerized glucose under hydrothermal condition . In vitro experimental results show that overcoating by glucose- derived material is an effective method to reduce the cytotoxicity of nanoparticles without significant effect on "heat generating" ability. Finally, the conclusions were summarized in Chapter 7 .