Synthesis And Characterization Of Nanomaterials With Special Morphologies By Low-heating Solid-state Chemical Reaction

Nanostructured materials are a focused research field due to their unusual properties and potential applications ranging from mesoscopic research to the development of nanodevices. Especially, all sorts of nanoscale materials with specific structure or interesting morphology, such as one-dimensional (ID) nanomaterials and hollow nanostructures have become the focus of materials research. These reported methods for preparing ID nanomaterials and hollow nanostructures usually require multi-process, higher temperature, special instruments and rigorous conditions. In this paper, a series of ID nanomaterials and hollow nanostructures were prepared by simple and convenient low-heating solid-state chemical reaction methods with the assistance of a nonionic surfactant, polyethylene glycol (PEG). Compared with these reported methods, surfactant-assisted solid-state chemical reaction is a good synthetic method for nanomaterials with special morphologies because of its advantages such 'as simple technique, low temperature, no special instrument et al.This paper is divided into three parts. The first part introduces some basically conception of nanomaterials, nanostructured materials and ID nanomaterials. The synthetic method and the developing foreground for ID nanomaterials were also presented. The history and advantages of low-heating solid-state chemical reaction were introduced. Based on the advantages of solid-state chemical reaction method, the investigative subject of the paper was proposed.The second part includes five chapter: synthesis and characterization of ID oxide nanorods, ID hydroxide nanorods, ID metal oxalate complex nanorods, hollow metallic oxalate complex nanostructures, metallic malonate and tartratecomplex nanostructure with special morphologies.In the first chapter, ZnO nanospheres was prepared by one-step solid-state chemical reaction of zinc salt and sodium hydroxide, ZnO and PbO nanorods were synthesized by solid-state chemical reaction of zinc (lead) salt and NaOH in the presence of PEG 400. The compositions of samples were determined by XRD. The sphere-like or rod-like morphology of samples were observed by TEM and SEM. The optical properties of ZnO were studied by IR, UV and PL. Results show that the ultraviolet absorption intension of nanoscale ZnO was stronger than bulk ZnO, and the peaks in IR and PL of nanoscale ZnO become blue-shift. The reactive processes and mechanisms of one-step solid-state reaction were discussed. It can be summarized that oxide can be directly obtained by solid-state reaction of metallic salt and NaOH or KOH if corresponding metal hydroxides have low decomposition temperature or are of unsteadiness.In the second chapter, Cd(OH)2, Co(OH)2 and Sr(OH)a nanorods were synthesized by solid-state chemical reaction of metallic salt and NaOH in the presence of PEG 400. The compositions of samples were characterization by XRD and TG. The rod-like morphologies of samples were observed by TEM and SEM. The morphologies of samples were also investigated when different salts were selected as reactants. Results show that the morphologies of samples are different when reactants have different structures.In the third chapter, CoC2O4-2H2O, CuC2O4, and NiC2O4-2H2O nanorods were synthesized by solid-state chemical reaction of metallic salts and oxalic acid in the presence of PEG. The compositions of samples were characterization by XRD and TG. The rod-like morphologies of samples were observed by TEM and SEM. The structural water was determined by TG and IR. The morphologies of samples were also investigated when different salts were selected as reactants andPEG with different degree of polymerization were selected as surfactant, and found different. The formational mechanism of nanorods was also discussed. It was found that the surfactant plays an important soft-template role in the growth process of nanorods.In the forth chapter, hollow ZnC2O4-2H2O, MgC2O4-2H2O, MnC2O4-2H2O and SrC2O2H2O nanostructures with different morphologies were synthesized by solid-state chemical...