In this work, we present a solvothermal method for the synthesis of hematite thin films on fluorine-doped tin oxidesubstrates. This simple method uses a precursor solution of iron(III) 2,4-pentanedionate dissolved in ethanol with amicroliter-scale amount of water and yields hematite ~ 500-nm thick films after annealing. The synthesised filmswere characterised using an array of methods, including scanning electron microscopy, energy-dispersive X-ray spectroscopy, diffuse reflectance, and powder x-ray diffraction. Incorporating water into the precursor solution provides nucleation sites for the reaction and results show that by altering the amount of water used in the synthesis, it is possible to generate nanocrystalline films of different morphologies, nanocrystal size distributions, and surface areas. This synthetic procedure therefore provides control over the films’ physical and electrochemical characteristics. Doping of hematite thin films is also possible using this synthesis, as exemplified by doping with tin by adding tin(II) 2,4-pentanedionate to the precursor solution. To demonstrate utility, we build prototype photoelectrochemical cells using the synthesized hemtatite as the photoanode.

中文翻译：

---

简单的溶剂热方法制备高度纳米结构的赤铁矿薄膜

在这项工作中，我们提出了一种溶剂热方法，用于在氟掺杂的氧化锡衬底上合成赤铁矿薄膜。这种简单的方法使用溶解于乙醇的2,4-戊二酸铁（III）（III）的前体溶液和微升规模的水，退火后可得到约500 nm厚的赤铁矿薄膜。使用一系列方法对合成膜进行了表征，包括扫描电子显微镜，能量色散X射线光谱法，漫反射率和粉末X射线衍射。将水掺入前体溶液中为反应提供了成核位点，结果表明，通过改变合成中使用的水量，可以生成具有不同形态，纳米晶体尺寸分布和表面积的纳米晶体膜。因此，该合成程序可控制薄膜的物理和电化学特性。赤铁矿薄膜的掺杂也可以使用这种合成进行，例如通过向前体溶液中添加2,4-戊二酸锡（II）来掺杂锡。为了证明其实用性，我们使用合成的蒙脱石作为光阳极来构建原型光电化学电池。