Natarajan Kaushik, Bhatt Parth, Yadav Pankaj, Pandey Kavita, Tripathi Brijesh, Kumar Manoj
Department of Solar Energy, School of Technology, Pandit Deendayal Petroleum University, Gandhinagar 382007, India.
Department of Science, School of Technology, Pandit Deendayal Petroleum University, Gandhinagar 382007, India.
J Nanosci Nanotechnol. 2018 Mar 1;18(3):1856-1863. doi: 10.1166/jnn.2018.11761.
Hematite (α-Fe2O3) nanostructures have been extensively studied as photo-anodes for the conversion of sunlight into chemical fuels by water splitting. A number of factors limit the photo-activity of pristine hematite nanostructures, including poor electrical conductivity and long penetration depth of light. Previous studies have shown that use of tin (Sn) as an n-type dopant can substantially enhance the photoactivity of hematite photoanodes by modifying their morphological, optical and electrical properties. This article presents impedance spectroscopic investigation of interplay between Sn-doping and the photoanode performance for photoelectrochemical water splitting using hematite nanostructure. Mott-Schottky measurements show that the Sn dopant serves as electron donor and increases the donor density of Sn-doped α-Fe2O3 nanostructured layer to 2.39 × 1019 cm-3. Photoelectrochemical impedance spectroscopy shows efficient photogenerated charge transfer from hematite to electrolyte in Sn-doped α-Fe2O3 nanostructure. The Sn-doped α-Fe2O3 nanostructure exhibit a photocurrent density of 1.2 mA/cm2 at 1.4 V versus RHE electrode.
赤铁矿（α-Fe₂O₃）纳米结构作为通过水分解将太阳光转化为化学燃料的光阳极已得到广泛研究。许多因素限制了原始赤铁矿纳米结构的光活性，包括电导率差和光的穿透深度长。先前的研究表明，使用锡（Sn）作为n型掺杂剂可以通过改变其形态、光学和电学性质来显著提高赤铁矿光阳极的光活性。本文介绍了使用赤铁矿纳米结构对光电化学水分解中Sn掺杂与光阳极性能之间相互作用的阻抗谱研究。莫特-肖特基测量表明，Sn掺杂剂作为电子供体，将Sn掺杂的α-Fe₂O₃纳米结构层的施主密度提高到2.39×10¹⁹ cm⁻³。光电化学阻抗谱表明，在Sn掺杂的α-Fe₂O₃纳米结构中，光生电荷从赤铁矿到电解质的转移效率很高。与RHE电极相比，Sn掺杂的α-Fe₂O₃纳米结构在1.4 V时表现出1.2 mA/cm²的光电流密度。
