Lanthanoid Sesquioxide Ultrafine Nanoparticles on Graphene via General Approach of Ultrafast Redox Reaction and Their Performance as Anodes in Lithium-Ion Batteries

Herein, we propose a general route of obtaining reduced graphene oxide and metal oxide nanocomposite, demonstrated by cerium, dysprosium, and neodymium sesquioxides, via ultrafast redox reaction (URR). This method utilizes a very fast heating of graphene oxide and a metal salt without any chemical solvents or special reactors. Off the scene tests showed that different ratios of graphene oxide to metal salt change the metal oxide particle size. Morphological, structural, physicochemical, and electrochemical properties were investigated. It was proved via X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) data that it was also possible to oxidize dysprosium acetate and neodymium nitrate at 300 °C, which normally would require much higher temperatures. As-obtained nanocomposites were tested as anodes in Li-ion batteries, but their applications should be further expanded to different fields. As Li-ion anodes, they delivered capacity as high as 1173 mAh/g at 0.05 A/g. Interestingly, <i>ex situ</i> measurements of the anode material showed that upon charging ceria is activated to form multiwalled carbon nanotubes. In this respect, we believe that the URR route is an ultrafast method (lasts in an eyeblink emitting colorful sparkles and smoke) to design graphene/metal oxide nanocomposites with tuned nanoparticle size at lower temperatures and without solvents which represents a facile and environmentally friendly approach for various applications.