离子液体中电沉积金属钛的研究
发布时间：2018-11-01 13:08
【摘要】：金属钛具有优异的耐蚀性、比强度高、质轻和良好的生物相容性等特点,被美誉为“太空金属”,广泛用于航空航天、石油化工、能源、生物医疗等领域。目前,工业上生产钛的方法主要为Kroll法,但存在工艺流程长,能耗大,环境污染严重等问题。而熔盐电解法存在能耗大、设备腐蚀严重、电流效率低等问题,难以实现工业化。离子液体具有极低的蒸汽压、较宽的电化学窗口、室温下呈液态、可设计性等特点,它的出现为低温电沉积钛开辟了新的道路。目前,用于电沉积金属钛的离子液体多为咪唑类离子液体,然而咪唑类离子液体的电化学窗口较窄,并不适用于金属钛的沉积。本文以上述背景出发,筛选出两种适合沉积钛的离子液体,并且系统的研究了离子液体中金属钛的电沉积过程。本论文的主要研究内容以及成果具体如下:(1)合成了[BisoMPyrr]NTf_2和[N1,2,2,4]NTf_2两种离子液体,并采用1H NMR、13C NMR以及质谱对其结构进行表征,证明为目标离子液体,通过对杂质进行检测,离子液体纯度很高,均能达到电化学实验的要求。(2)分别测定了两种离子液体电导率,其电导率都随着温度的升高而升高。在两种离子液体中分别加入TiCl_4之后,电导率有所降低。并且电导率对数lnκ与温度的倒数l/T呈线性关系,符合Arrhenius方程。(3)采用[BisoMPyrr]NTf_2-TiCl_4体系进行电沉积金属钛的研究,循环伏安测试表明阴极上钛的还原至少为两步。XRD及XPS的结果表明,沉积层中钛主要是以TiCl_3和TiO_2的形式存在,生成的TiCl_3附着在电极表面阻碍进一步还原,沉积得到的少量Ti在空气中被氧化成TiO_2。紫外吸收结果表明沉积后体系中已检测不到Ti(Ⅳ),而同时也没有获得到Ti(Ⅱ)的吸收峰。(4)以[N1,2,2,4]NTf_2-TiCl_4体系进行电沉积钛的研究,循环伏安测试表明钛的还原为三步电子转移。沉积层表面形貌不均匀,晶体的形状为不规则、独立的颗粒状。能谱显示基底银含量太高,钛含量比较低。XRD结果表明,在沉积层中有TiO_2和金属Ti的存在。紫外吸收结果表明沉积后体系中检测不到Ti(Ⅳ),也没有Ti(Ⅱ)的吸收峰。
[Abstract]:Titanium has excellent corrosion resistance, high specific strength, light weight and good biocompatibility. It is widely used in aerospace, petrochemical, energy, biomedical and other fields. At present, the main method of titanium production in industry is Kroll process, but there are many problems, such as long technological process, high energy consumption, serious environmental pollution and so on. However, molten salt electrolysis has many problems, such as high energy consumption, serious equipment corrosion and low current efficiency, so it is difficult to realize industrialization. Ionic liquids have the characteristics of very low vapor pressure, wide electrochemical window, liquid state at room temperature and designability. The appearance of ionic liquids opens a new way for low temperature electrodeposition of titanium. At present, the ionic liquids used in electrodeposition of titanium metal are mostly imidazole ionic liquids, however, the electrochemical window of imidazole ionic liquids is narrow, so it is not suitable for the deposition of titanium metal. Based on the above background, two kinds of ionic liquids suitable for titanium deposition were selected, and the electrodeposition process of titanium in ionic liquids was studied systematically. The main contents and achievements of this thesis are as follows: (1) two kinds of ionic liquids, [BisoMPyrr] NTf_2 and [N1O2O2O4] NTf_2, were synthesized, and their structures were characterized by 1H NMR,13C NMR and mass spectrometry. It is proved that the ionic liquid is the target ionic liquid, and the purity of the ionic liquid is very high, which can meet the requirements of electrochemical experiment. (2) the conductivity of two kinds of ionic liquids is measured, and the conductivity increases with the increase of temperature. After the addition of TiCl_4 into the two ionic liquids, the conductivity decreased. And the logarithmic ln 魏 has a linear relationship with the reciprocal 1 / T of temperature, which accords with the Arrhenius equation. (3) the electrodeposition of titanium metal is studied by [BisoMPyrr] NTf_2-TiCl_4 system. Cyclic voltammetry showed that the reduction of titanium on the cathode was at least two steps. The results of XRD and XPS showed that the titanium in the deposited layer mainly existed in the form of TiCl_3 and TiO_2, and the formed TiCl_3 adhered to the electrode surface to prevent further reduction. A small amount of Ti deposited in air was oxidized to TiO_2. The ultraviolet absorption results show that Ti (鈪，
本文编号：2304012
[Abstract]:Titanium has excellent corrosion resistance, high specific strength, light weight and good biocompatibility. It is widely used in aerospace, petrochemical, energy, biomedical and other fields. At present, the main method of titanium production in industry is Kroll process, but there are many problems, such as long technological process, high energy consumption, serious environmental pollution and so on. However, molten salt electrolysis has many problems, such as high energy consumption, serious equipment corrosion and low current efficiency, so it is difficult to realize industrialization. Ionic liquids have the characteristics of very low vapor pressure, wide electrochemical window, liquid state at room temperature and designability. The appearance of ionic liquids opens a new way for low temperature electrodeposition of titanium. At present, the ionic liquids used in electrodeposition of titanium metal are mostly imidazole ionic liquids, however, the electrochemical window of imidazole ionic liquids is narrow, so it is not suitable for the deposition of titanium metal. Based on the above background, two kinds of ionic liquids suitable for titanium deposition were selected, and the electrodeposition process of titanium in ionic liquids was studied systematically. The main contents and achievements of this thesis are as follows: (1) two kinds of ionic liquids, [BisoMPyrr] NTf_2 and [N1O2O2O4] NTf_2, were synthesized, and their structures were characterized by 1H NMR,13C NMR and mass spectrometry. It is proved that the ionic liquid is the target ionic liquid, and the purity of the ionic liquid is very high, which can meet the requirements of electrochemical experiment. (2) the conductivity of two kinds of ionic liquids is measured, and the conductivity increases with the increase of temperature. After the addition of TiCl_4 into the two ionic liquids, the conductivity decreased. And the logarithmic ln 魏 has a linear relationship with the reciprocal 1 / T of temperature, which accords with the Arrhenius equation. (3) the electrodeposition of titanium metal is studied by [BisoMPyrr] NTf_2-TiCl_4 system. Cyclic voltammetry showed that the reduction of titanium on the cathode was at least two steps. The results of XRD and XPS showed that the titanium in the deposited layer mainly existed in the form of TiCl_3 and TiO_2, and the formed TiCl_3 adhered to the electrode surface to prevent further reduction. A small amount of Ti deposited in air was oxidized to TiO_2. The ultraviolet absorption results show that Ti (鈪，
本文编号：2304012
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