过渡金属氧化物纳米材料结构与光电化学性能研究

发布时间：2018-01-08 13:04

本文关键词：过渡金属氧化物纳米材料结构与光电化学性能研究　出处：《中国科学技术大学》2017年硕士论文　论文类型：学位论文

【摘要】：全球能源短缺和环境污染危机使得发展环境友好型新能源成为世界性课题。太阳能相比于其它常见能源来说具有环境友好,无污染且用之不尽取之不竭,有效功率巨大等优点,然而,如何有效地利用太阳能是目前面临的一个巨大挑战。将太阳能转化为化学能是光电化学领域的一个主要研究课题,而过渡金属氧化物因其优良的光电性能成为了一种具有极具发展潜能的光电催化剂材料,但过渡金属氧化物存在着较短的电子扩散长度和缓慢的电子迁移率,因此存在光生电子空穴对难于有效分离的问题极待解决。在本论文中,我们通过水热法成功制备了非晶氧缺陷三氧化钼纳米球颗粒,其结构中的氧缺陷导致样品在可见至近红外波段有很强的等离子体吸收响应,成功抑制了半导体内光生载流子的复合,提高了其光响应电流;探索了氧化亚铜纳米片半导体材料的合成和光电化学催化性能。论文利用同步辐射X射线吸收谱(XAFS)、X射线衍射(XRD)、扫描电子显微镜(SEM)、透射电镜(TEM)和X射线光电子能谱(XPS),光电化学平台等性能实验方法,研究了上述过渡金属氧化物材料原子结构和性能之间的关系。本论文主要研究内容如下:1、利用水热法合成了非晶态氧缺陷MoO3-x纳米球颗粒(A-MoO3-x)。该A-MoO3-x纳米球在可见及近红外波长区域有较强的等离子吸收效应,提高了太阳光的利用效率。该材料在光电催化水氧化实验中可作为一种有效的阳极材料,相比块状三氧化钼颗粒,A-MoO3-x纳米球样品具有更高的光电流密度。XAFS表征结果显示了材料中的氧缺陷使得非晶A-MoO3-x样品在局域结构呈现亚稳态六角结构,极大得提高了光生电荷分离效率。A-MoO3-x材料的等离子体吸收和非晶结构提高了其作为光电化学产氧的活性。2、利用水热法成功合成了 Cu20超薄纳米片材料。在光电化学催化性能测试结果中,其光反应响应结果相比块材料Cu2O颗粒,具有更高的光电流响应密度,表明了合成的Cu20纳米片具有更好的光电催化产氢性能。
[Abstract]:The global energy shortage and environmental pollution crisis make the development of environment-friendly new energy become a worldwide issue. Compared with other common energy, solar energy is environmentally friendly, pollution-free and inexhaustible. However, how to make effective use of solar energy is a great challenge at present. Converting solar energy into chemical energy is a major research topic in the field of photochemistry. Transition metal oxide (TME) has become a potential photocatalyst because of its excellent photoelectric properties, but the transition metal oxide has short electron diffusion length and slow electron mobility. Therefore, the problem of photoelectron hole is difficult to be effectively separated. In this thesis, we successfully prepared amorphous oxygen defect molybdenum trioxide nanospheres by hydrothermal method. The oxygen defect in the structure leads to a strong plasma absorption response in the visible to near infrared band, which successfully inhibits the recombination of photogenerated carriers in the semiconductor and improves the photoresponse current. The synthesis and photochemical catalytic properties of cuprous oxide nanocrystalline semiconductor materials were investigated in this paper. The synchrotron radiation X-ray absorption spectra (XAFS) and X-ray diffraction (XRD) were used. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), photochemical platform and so on. The relationship between atomic structure and properties of the transition metal oxide materials mentioned above has been studied. The main contents of this thesis are as follows: 1. Amorphous oxygen defect MoO3-x nanospheres (A-MoO _ 3-x) were synthesized by hydrothermal method. The A-MoO _ 3-x nanospheres have strong plasma absorption effect in the visible and near infrared wavelength regions. This material can be used as an effective anode material in photocatalytic water oxidation experiments, compared with bulk molybdenum trioxide particles. A-MoO _ 3-x nanospheres have higher photocurrent density. XAFS characterization results show that oxygen defects in the material make the amorphous A-MoO _ 3-x sample have metastable hexagonal structure in the local structure. . The plasma absorption and amorphous structure of the photogenerated charge separation efficiency. A-MoO _ 3-x have been greatly improved. The ultrathin Cu20 nanocrystals were successfully synthesized by hydrothermal method. In the photochemical catalytic performance test results, the photoreaction response results were compared with the Cu2O particles. The photocurrent response density is higher, which indicates that the synthesized Cu20 nanocrystals have better photocatalytic hydrogen production performance.
【学位授予单位】：中国科学技术大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB383.1;O611.62

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