不同参数特性钛基膜电极的制备及其仿生制氢性能

发布时间：2018-03-29 01:14

  本文选题：仿生制氢　切入点：光阳极　出处：《北京工业大学》2015年硕士论文

【摘要】：人工仿生制氢技术以取之不尽用之不竭的太阳能制取清洁高效的氢气,对缓解能源危机、改善人类生存环境和实现可持续发展有重要意义。开发具有更高光生载流子分离效率和光氢转换效率的钛基膜光阳极是人工仿生制氢技术研究的重点之一。本论文研究利用飞秒激光沉积法制备了TiO2纳米粒子膜,利用阳极氧化法制备了TiO2纳米管光子晶体膜和TiO2纳米棒阵列膜,并对所制得的TiO2纳米管光子晶体膜和TiO2纳米棒阵列膜进行了EosinY染料敏化,进而利用SEM、AFM、XPS、XRD、UV-Vis DRS等物理化学手段和光电流密度时间曲线、光电压时间曲线和Mott-Schottky曲线等电化学手段对所制光电极的表面形貌、元素组成、晶型、光响应性能和光电化学性能进行了综合分析。用飞秒激光沉积法制备出TiO2纳米粒子膜,在较高靶室氧压(1mbar)下沉积得到的TiO2纳米粒子的平均直径为240nm,且具有相对较大粒子间的空隙率,而在较低氧压(0.1mbar)下制得的样品平均粒径为100nm,其粒子分布密度较大且粒径分布较窄。随着沉积时间的增长,更多的TiO2纳米粒子聚集到Ti基底上,这在光电制氢过程中能够产生更多光活性位。当靶室氧压为1mbar和沉积时间为3h,所制得的TiO2纳米粒子膜经500°C在空气中热处理后为纯金红石晶相,比在靶室真空条件下制得的混晶相样品的光化学电性能好。用两步阳极氧化法制备出TiO2纳米管光子晶体膜,其在管长2μm的纳米管阵列表面具有周期性蜂窝环状结构,环边长约为150nm,环壁厚约为40nm,所制TiO2纳米管光子晶体膜在400~800nm区域出现光子晶体所特有的多次振荡吸收峰,经过水溶和醇溶EosinY 12小时的染料敏化后,样品出现染料特征吸收峰。经染料敏化得Ti O2纳米管光子晶体电极的光电性能有很大提高,且醇溶EosinY染料敏化后的光子晶体光电性能提高幅度大于水溶EosinY,具有最高光电化学性能的样品的染料敏化时间为8小时。用阳极氧化法通过控制升压速率制备出TiO2纳米棒阵列膜,纳米棒直径约为20-30nm,纳米棒长度50-150nm。对其进行12小时的醇溶EosinY染料敏化,敏化后的TiO2纳米棒阵列膜在450-800nm处的吸光性有明显提高,且光电化学性能有所提高。基于上述研究对不同方法制备的钛基膜电极的表面参数对光电流密度、光电压以及染料敏化过程的影响进行了综合分析。在所制TiO2纳米粒子膜、TiO2纳米管光子晶体膜和Ti O2纳米棒阵列膜中,膜厚对光电流影响最大,而对光电压影响较小,其中管长为2μm的TiO2纳米管光子晶体膜具有最大光电流密度。TiO2纳米粒子膜由粒径为100~240nm团簇粒子构成,具有最大的光电压。相对于纳米棒阵列膜,纳米管光子晶体膜的表面蜂窝环状结构更有利于染料的吸附和键联。
[Abstract]:Artificial bionic hydrogen production technology to inexhaustible solar energy to produce clean and efficient hydrogen, to alleviate the energy crisis, It is of great significance to improve human living environment and realize sustainable development. The development of titanium substrate photocathode with higher photovoltaic carrier separation efficiency and photohydrogen conversion efficiency is one of the emphases of artificial bionic hydrogen production technology. In this paper, TiO2 nanocrystalline films were prepared by femtosecond laser deposition. TiO2 nanotube photonic crystal film and TiO2 nanorod array film were prepared by anodic oxidation method. The TiO2 nanotube photonic crystal film and TiO2 nanorod array film were sensitized by EosinY dye. Then the surface morphology, elemental composition and crystal form of the photoelectrode were investigated by means of physical and chemical means, such as SEMMA-AFMS-XRDX DRS, photocurrent density time curve, photovoltage time curve and Mott-Schottky curve, etc. The photoresponse and photochemical properties of TiO2 nanoparticle films were synthesized by femtosecond laser deposition. The average diameter of the TiO2 nanoparticles deposited at a high oxygen pressure of 1 mb is 240 nm, and the porosity of the particles is relatively large. The average particle size of the sample was 100 nm under the condition of low oxygen pressure (0.1mb), and the particle density was higher and the particle size distribution was narrower. With the increase of deposition time, more TiO2 nanoparticles gathered on Ti substrate. When the oxygen pressure in the target chamber is 1mbar and the deposition time is 3 h, the prepared TiO2 nanoparticles film is pure rutile crystal phase after heat treatment in air at 500 掳C. The photonic crystal films of TiO2 nanotubes were prepared by two-step anodization method, and they had periodic honeycomb ring structure on the surface of nanotube arrays with 2 渭 m in length. The length of the ring side is about 150 nm, and the thickness of the ring wall is about 40 nm. The photonic crystal film of TiO2 nanotubes has several oscillatory absorption peaks unique to photonic crystals in the region of 400~800nm, and is sensitized by water solution and 12 hours of EosinY solution. The photovoltaic properties of TIO _ 2 nanotube photonic crystal electrode were greatly improved by dye sensitization. The photosensitized photonic crystal of alcohol-soluble EosinY dye is more effective than the water-soluble Eosin Y. the dye sensitization time of the sample with the highest photoelectrochemical property is 8 hours. The TiO2 nanorod array film was prepared by anodic oxidation method by controlling the voltage rise rate. The diameter of nanorods was about 20-30 nm, and the length of nanorods was 50-150 nm. The sensitized TiO2 nanorod arrays were sensitized with alcohol-soluble EosinY dyes for 12 hours. The absorptivity of TiO2 nanorod array films at 450-800nm was improved obviously. Based on the above research, the surface parameters of titanium substrate electrode prepared by different methods were compared with the optical current density. The effects of photovoltage and dye sensitization were comprehensively analyzed. In the photonic crystal films of TiO2 nanotubes and TIO 2 nanorods array films, the thickness of the films had the greatest effect on photocurrent, but little effect on the photovoltage. The TiO2 nanotube photonic crystal film with 2 渭 m tube length has the maximum photocurrent density. The TiO2 nanoparticles film is composed of 100~240nm cluster particles with the largest photovoltage. The honeycomb ring structure of nanotube photonic crystal film is more favorable for dye adsorption and bonding.
【学位授予单位】：北京工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ116.2
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本文编号：1678894