纳米多孔银基底材料的可控制备及其性能研究

发布时间：2018-08-26 09:23

【摘要】：本论文报道了一种快速、简单的新方法,制得由纳米粒子构建而成的三维、大面积、具有开放式连续孔结构、形貌和尺寸可控的纳米多孔银材料,探讨了不同反应参数对形貌和尺寸的影响。并研究了其作为SERS活性基底材料和电化学电极基底材料的应用。主要包括：(1)用化学刻蚀法制备了三维、大面积、具有均匀开放式孔结构的纳米银材料。整个合成过程包括：银纳米海绵结构的常温制备、压片过程及化学刻蚀。为了获得均匀纳米孔结构,研究了反应参数的影响。发现,常温、16%硝酸浓度是获得三维纳米多孔银材料的最优条件。最优条件下获得的纳米多孔银材料具有连续的网状结构与相互连接的孔结构。这种网状结构的韧带由很多平均粒径在-72nm的颗粒组成。平均孔径在90.5nm。对所涉及的基于刻蚀时间的纳米孔结构的形成演化过程和刻蚀机制进行了探讨。(2)基于所制备的多孔银基底材料突出的颗粒性,研究了该基体材料在表面增强拉曼散射分子检测中的应用。通过对粒子尺寸、表面粗糙度和孔尺寸等进行调控,优化了基体材料对吸附在其表面的罗丹明分子的检测灵敏度。可检测的最低浓度达10-6M,比国际上报道的最低浓度(10-14M)高2个数量级,且特征峰强度变化量的相对标准偏差低于6%。显示了突出的检测灵敏度和稳定的重复性。(3)以所制备的纳米多孔银材料为基底,采用水热法生长纳米C0304从而制得Ag/Co3O4复合电极材料。材料具有优秀的离子扩散、质子迁移和电荷转移能力,以及良好的导电性及电荷存储性能。优选的Ag/Co3O4电极材料(C0304覆盖在银网状韧带上)显示出极高的比电容值,在lAg-1电流密度下比电容值高达1276Fg-1,远高于之前报道的各种不同形貌的Co3O4纯物质的电容值,也高于其他Co3O4-Ag复合纳米阵列电极。此外,这种电极材料还具有很好的放电容量(在10Ag-1仍有986Fg-1)和稳定性,经过2000次循环后仍有92%的电容剩余。
[Abstract]:In this paper, we report a fast and simple new method to fabricate three dimensional, large area, open and continuous porous silver materials with controllable morphology and size. The effects of different reaction parameters on morphology and size were discussed. Its application as SERS active substrate and electrochemical electrode substrate was studied. The main contents are as follows: (1) Nano-silver materials with large area and uniform opening pore structure were prepared by chemical etching. The synthesis process includes the preparation of silver nanosponges at room temperature, sheet pressing and chemical etching. In order to obtain uniform nanopore structure, the effect of reaction parameters was studied. It is found that 16% nitric acid concentration at room temperature is the best condition for obtaining three dimensional porous silver materials. The nano-porous silver materials obtained under the optimal conditions have continuous reticular structure and interlinked pore structure. The reticular ligaments consist of a number of particles with an average diameter of-72 nm. The average aperture is 90.5 nm. The formation and evolution process and etching mechanism of nano-pore structures based on etching time were discussed. (2) based on the outstanding particle properties of the prepared porous silver substrate materials, The application of the substrate in the detection of surface enhanced Raman scattering (SRS) was studied. By adjusting the particle size, surface roughness and pore size, the sensitivity of the matrix to Rhodamine molecules adsorbed on its surface was optimized. The lowest detectable concentration is 10-6m, which is two orders of magnitude higher than the lowest concentration (10-14M) reported internationally, and the relative standard deviation of the change of characteristic peak intensity is less than 6. The results show that the sensitivity and repeatability of Ag/Co3O4 are outstanding. (3) Ag/Co3O4 composite electrode materials are prepared by hydrothermal growth of nano-C0304 based on the prepared nano-porous silver materials. The materials have excellent ion diffusion, proton transport and charge transfer capabilities, as well as good electrical conductivity and charge storage properties. The selected Ag/Co3O4 electrode material (C0304 covered with silver reticular ligament) showed extremely high specific capacitance value, and the specific capacitance value at lAg-1 current density was 1276 Fg-1, which was much higher than the capacitance value of all kinds of Co3O4 pure materials with different morphologies reported previously. It is also higher than other Co3O4-Ag composite nanoscale array electrodes. In addition, the electrode has good discharge capacity (still 986Fg-1 at 10Ag-1) and stability. After 2000 cycles, the residual capacitance is still 92%.
【学位授予单位】：南京大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB383.1

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