Iron oxides with highly ordered mesoporosity for photoelectrochemical oxygen formation from water

赤铁矿(α-Fe_2O_3)是一种很有前途的光电化学电池水析氧阳极材料。为了克服这种材料的固有局限性，人们提出了纳米结构。因此，优化赤铁矿光阳极的形貌是本项目的最终目标。利用一种新型的溶胶-凝胶法(“砖和砂浆”)、电化学沉积和在三维介孔导电氧化铟锡(ITO)网络中的沉积，将合成具有可控有序介孔、大比表面积和高度结晶壁的赤铁矿。所有获得的纳米结构都将进行详细的光电化学表征，并将使用激光闪光光解和停流技术研究载流子动力学。由于已知在波长小于赤铁矿带隙能的光照射下，Fe(II)会发生光溶解，这可能会改变光阳极的形貌及其光电化学特性，因此将分析溶解沉淀机理，并阐述提高阳极长期稳定性的方法。

Hematite (α-Fe2O3) is discussed to be a promising material for the fabrication of photoanodes for the oxygen evolution from water in photoelectrochemical (PEC) cells. To overcome inherent limitations of this material nanostructuring has been proposed. Thus, the optimization of the morphology of hematite photoanodes is the ultimate goal of this project. Hematite with controlled ordered mesoporosity, large surface areas and highly crystalline walls will be synthesized by a novel sol-gel approach (“brick and mortar”), electrochemical deposition and deposition in a 3D-mesoporous conductive indium-tin oxide (ITO) network. All the obtained nanostructures will be photoelectrochemically characterized in detail and charge carrier dynamics will be studied employing laser flash photolysis and stopped-flow techniques. Since it is known that under irradiation with light of wavelengths smaller than the band gap energy of hematite photodissolution of iron(II) can occur and this might possibly alter the morphology of the photoanode and their photoelectrochemical characteristics, the dissolutionprecipitation mechanism will be analyzed and methods to improve the long-term stability of the anodes will be elaborated.