Serrapede Mara, Fontana Marco, Gigot Arnaud, Armandi Marco, Biasotto Glenda, Tresso Elena, Rivolo Paola
Center for Sustainable Future Technologies, Istituto Italiano di Tecnologia, Via Livorno 60, I-10144 Torino, Italy.
Department of Applied Science and Technology, Politecnico di Torino, C.so Duca degli Abruzzi 24, I-10129 Torino, Italy.
Materials (Basel). 2020 Jan 28;13(3):594. doi: 10.3390/ma13030594.
A simple, low cost, and "green" method of hydrothermal synthesis, based on the addition of -ascorbic acid (-AA) as a reducing agent, is presented in order to obtain reduced graphene oxide (rGO) and hybrid rGO-MoO aerogels for the fabrication of supercapacitors. The resulting high degree of chemical reduction of graphene oxide (GO), confirmed by X-Ray Photoelectron Spectroscopy (XPS) analysis, is shown to produce a better electrical double layer (EDL) capacitance, as shown by cyclic voltammetric (CV) measurements. Moreover, a good reduction yield of the carbonaceous 3D-scaffold seems to be achievable even when the precursor of molybdenum oxide is added to the pristine slurry in order to get the hybrid rGO-MoO compound. The pseudocapacitance contribution from the resulting embedded MoO microstructures, was then studied by means of CV and electrochemical impedance spectroscopy (EIS). The oxidation state of the molybdenum in the MoO particles embedded in the rGO aerogel was deeply studied by means of XPS analysis and valuable information on the electrochemical behavior, according to the involved redox reactions, was obtained. Finally, the increased stability of the aerogels prepared with -AA, after charge-discharge cycling, was demonstrated and confirmed by means of Field Emission Scanning Electron Microscopy (FESEM) characterization.
本文介绍了一种基于添加抗坏血酸（-AA）作为还原剂的简单、低成本且“绿色”的水热合成方法，用于制备还原氧化石墨烯（rGO）和用于制造超级电容器的rGO-MoO复合气凝胶。通过X射线光电子能谱（XPS）分析证实，所得氧化石墨烯（GO）的高度化学还原产生了更好的双电层（EDL）电容，循环伏安（CV）测量结果表明了这一点。此外，即使将氧化钼前驱体添加到原始浆料中以获得rGO-MoO复合化合物，含碳3D支架的良好还原产率似乎也是可以实现的。然后通过CV和电化学阻抗谱（EIS）研究了所得嵌入MoO微结构的赝电容贡献。通过XPS分析深入研究了嵌入rGO气凝胶中的MoO颗粒中钼的氧化态，并根据所涉及的氧化还原反应获得了有关电化学行为的有价值信息。最后，通过场发射扫描电子显微镜（FESEM）表征证明并确认了用-AA制备的气凝胶在充放电循环后的稳定性增强。
