Several Inorganic Nanomaterials: Preparation, Characterization And Application

Nanomaterials have become a hot issue in the field of international research astheir peculiar physical and chemical properties and their potential application in thechemical industry, environment, bio-materials, bio-medicine and other fields. Inrecent years, research about the relationship between structures and properties ofnano-materials, explore a simple and practical approach for chemical synthesis ofnano materials, explore novel properties of nanomaterials have become a focus ofattention. In this paper, on the basis of these mature the integrated application oftemplate method, solvothermal, hydrothermal and other methods, we have fabricatedand characterized several inorganic nanomaterials and their shape, size anddistribution can be well controlled. We have further studied lithium-ion batteryperformance, gas sensor properties and biosensor properties of the as-preparednanomaterials. The relationship between the nanostructure and their properties hasalso been investigated. The detailed materials are summarized as follows:In chapter2, mesoporous SnO₂fibers have been prepared via precipitation ofmetal ions on green cotton template with further calcinations. The anode comprised ofthis novel SnO₂structure exhibits large reversible capacity and exceptional capacityretention ability. The improved electrochemical performance can be attributed to thelarge surface mesoporous network structure of SnO₂fibers, which can provide fasttransport channels for the conductive ions and act as a buffer layer for volume changeduring lithium ion insertion/extraction. The gas sensor tests show that mesoporousSnO₂fibers also manifest good sensor performance towards ethanol with rapidresponse and high sensitivity, as the gas diffusion and mass transportation have beensignificantly enhanced by their unique structures.In chapter3, we developed a facile ethanol solvothermal approach to fabricatehighly disperse3D flowerlike SnS₂architectures. The effects of synthetic conditions,such as the solvent system and the concentration of thiourea, on the morphology ofthe products were investigated. A possible growth mechanism for the formation of3Dflowerlike architectures was preliminarily propounded on the basis of the evolution ofthe structure and the morphology with increasing the reaction time. As anodematerials of rechargeable Li-ion batteries, the as-prepared flowerlike SnS₂structuresexhibited exceptional good electrochemical properties, which revealed a higher reversible capacity about502mA h g^-1and more stable cyclic retention at50th cyclethan the as-prepared SnS₂nanoplates. The reasons for the improved electrochemicalperformance of the flowerlike structures have been proposed. All the resultsdemonstrated that they were potential anode materials in Li-ion batteries. A facilechemical bath deposition （CBD） approach has been developed to fabricating SnS₂nanowall （NW） arrays directly on copper foils. As an anode material for lithium ionbattery, the NW arrays exhibit enhanced lithium ion storage property. At a rate of0.3C, the NW arrays maintain a capacity of about700mAh g^-1after40cycles. Even at ahigh rate of1.2C, the NW arrays can still deliver a stable capacity of400mAh g^-1.The high electrochemical performance is well related to the in situ growth of uniformSnS₂nanosturctures on a conductive copper current collector, which results in arobust adhesion for the SnS₂NW on the copper, and leads to an enhanced electronconductivity, improved lithium ion transport, and sustained volume variations.In chapter4, a novel non-enzymatic hydrogen peroxide sensor was realized fromMn-nitrilotriacetate acid （Mn-NTA） nanowires, which were fabricated via a facilehydrothermal route. Cyclic voltammetry （CV） revealed that the Mn-NTA nanowiresexhibited direct electrocatalytic activity for the oxidation of H₂O₂in phosphate buffersolution. The sensor showed linear response to H₂O₂at the concentrations range from5×10-6to2.5×10^-3M with a detection limit of2×10^-7 The sensitivity was up to78.9μAμM^-1cm^-2. These results indicated that the Mn-NTA nanowires werepromising in realizing non-enzymatic H₂O₂detection.