新型全氧化物复合纳米结构光阳极的制备、光解水性能与界面动力学研究

项目名称： 新型全氧化物复合纳米结构光阳极的制备、光解水性能与界面动力学研究

项目编号： No.51472080

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 一般工业技术

项目作者： 王喜娜

作者单位： 湖北大学

项目金额： 80万元

中文摘要： 光解水电池是将太阳能转换为氢能（STH）的一种有效途径，由于其光电流主要受限于较低的阳极电流，因此提高光阳极的STH效率非常重要。针对目前光阳极材料的带隙较宽、过电位较高、电荷传输较慢、化学性质欠稳定等问题，我们提出构筑TiO2/CoOx全氧化物复合纳米结构电极， 采用CoO和/或Co3O4纳米颗粒修饰TiO2纳米结构（如纳米管、纳米棒阵列及纳米棒+纳米花结构），对其结构和界面进行调控，通过提高TiO2的比表面积来提高CoOx的载量和反应面积进而增强光吸收，利用二者的界面能级偏移加快电荷分离和传输，并降低析氧反应（OER）过电位。同时，对共催化剂（Co-Pi或Ni(OH)2）修饰前后电极的光电化学性能、光解水性能与界面能级结构展开系统研究，通过双恒电位技术研究TiO2/CoOx与催化剂工作电极电位的动态关联，揭示其界面动力学机制，通过优化催化剂沉积工艺加速OER过程，最终提高STH效率。

中文关键词： 复合纳米结构；光解水；半导体；光阳极；界面动力学

英文摘要： Solar water splitting device is an efficient way for solar to hydrogen (STH) conversion. Since its photocurrent is always limited by the low anodic current of photoanode, it is very important to increase the STH efficiency of photoanodes. To overcome the problems relevant to photoanode materials, such as wide band gap, high overpotential, sluggish charge transport and chemical unstability, we proposed here to construct TiO2/CoOx heterostructure nanocomposite photoanodes, all of which are composed of oxides. CoO or/and Co3O4 nanocrystals will be adopted to decorate TiO2 nanostructures including nanotube, nanorod arrays and nanorods plus nanoflowers. The structure and interfaces of the photoanodes will be tuned. High absorption over visible light, high loading density of CoOx and large reaction area with water will be obtained by increasing the surface area of TiO2. Efficient charge separation and fast charge transport, together with lower overpotential of oxygen evolution reaction (OER), will be achieved through the interfacial energy band offset between TiO2 and CoOx. At the same time, the photoelectrochemical (PEC), solar water splitting property and interfacial energy structure will be systematically studied before and after the decoration of OER cocatalysts such as Co-Pi and Ni(OH)2. Bi-potentiostat technique will be used to study the dynamic potential relevance between the TiO2/CoOx and OER working electrodes, combined with the interfacial energetics and charge transport process, the factors that affect the interface energetics will be disclosed. Then the deposition process will be optimized to accelerate the OER kinetics, and increase the STH efficiency finally.

英文关键词： Nanocomoposite;Solar water splitting;Semiconductor;Photoanode;Interfacial energetics