Cr3+/氧空位共修饰SrTiO3光阳极的调控制备及其对金属光电化学阴极保护性能协同影响机制研究

项目名称： Cr3+/氧空位共修饰SrTiO3光阳极的调控制备及其对金属光电化学阴极保护性能协同影响机制研究

项目编号： No.41506093

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 天文学、地球科学

项目作者： 补钰煜

作者单位： 中国科学院海洋研究所

项目金额： 21万元

中文摘要： 钛酸锶具有较负的导带电位，是优异的光电化学阴极保护材料。铬掺杂可扩展其光吸收范围至可见光区，同时铬具有金属钝化效应。但铬元素会在钛酸锶晶体内形成Cr3+和Cr6+的掺杂态，后者在钛酸锶导带下沿形成掺杂能级，致使其导带电位正移，并演化为载流子复合中心。本项目中，首先制备铬掺杂钛酸锶纳米材料，之后通过可控的高温氢处理还原法、NaBH4还原法、火焰喷烧还原法，调控铬掺杂价态从+6向+3转变，消除负效应掺杂能级。随后，增强还原氛围强度，在钛酸锶晶体表面形成氧空位，制备Cr3+/氧空位共修饰钛酸锶光电转换材料。利用氧空位的形成增加钛酸锶载流子浓度，提升光生电子迁移能力。最后，通过电化学、光电化学、染料协助稳态荧光光谱、理论技计算等研究手段，对比研究系列材料的能级结构、载流子浓度、表面态浓度、电子扩散系数以及光生电子寿命等理化性质，分析Cr3+/氧空位共修饰对钛酸锶光电化学阴极保护性能的影响机制。

中文关键词： 光电化学阴极保护；钛酸锶；铬掺杂能级调控；氧空位；共修饰

英文摘要： SrTiO3, which has a relative negative conduction band potential, is an excellent material for photoelectrochemical cathodic anticorrosion. Cr doping could expand the light absorption range of SrTiO3 to visible light region and lead to the formation of Cr3+ and Cr6+ doping states in the SrTiO3 crystal, the latter of which would form doping energy level under the conduction band of SrTiO3. So the doping Cr would shift the valence band potential of SrTiO3 positively and evolve into carrier recombination center. In this project, Cr-doped SrTiO3 nanomaterial was prepared by sol-gel method at first and then by controllable high temperature hydrogen treatment reduction, NaBH4 reduction and high temperature flame burning reduction methods, the valence state of the doping Cr was adjusted from +6 to +3 to eliminate negative effect doping energy level. Furthermore, the intensity of reduction ambient was enhanced to form oxygen vacancy on the surface of SrTiO3 crystal, thus Cr3+/ oxygen vacancy co-modified SrTiO3 photoelectric conversion material was prepared. The formation of oxygen vacancy could increase the carrier concentration in the conduction band of SrTiO3 and enhance the transfer ability of photo-generated electrons. At last, by combination of the electrochemical, photoelectrochemical, dye assisted steady-state fluorescence spectra and theoretical calculation methods, the energy level structure, carrier concentration, surface state concentration, electron diffusion coefficient and photo-generated electron lifetime et al. of those matirials were tested to help analyze the impact of Cr3+/ oxygen vacancy co-modification on the photoelectrochemical cathodic anticorrosion performance of SrTiO3.

英文关键词： Photoelectrochemical cathodic protection;SrTiO3;Cr doping energy level regulation;Oxygen Vacancy;Co-modification