Electrochemical Synthesis of Size-Tuned Carbon-Coated Stanene Quantum Dots at Room Temperature for High-Performance Lithium-Ion Batteries

Quantum Dots have received extensive attention recently, paving the way for exploring their utility due to their intriguing size-dependent properties, solubility manipulation, and susceptibility to surface modification/doping. Among all types of quantum dots, Stanene is a topological insulator exhibiting enhanced spin-orbit coupling, making it a promising zero-dimensional material with augmented optical and electrical properties. Given these exceptional characteristics, the development of efficient methods to synthesize Stanene quantum dots with precise size distribution is of significant interest. We report the electrochemical transformation of Tin powder to carbon-coated stanene quantum dots at room temperature in a non-aqueous media. Ultraviolet-visible and photoluminescence spectroscopy results confirm the size-dependent properties of stanene quantum dots. Transmission electron micrographs, powder X-ray diffraction, and Fourier transform infrared analysis further supplement the size-dependent properties of these quantum dots, which are potential candidates for applications in catalysis, sensors, energy storage and medical imaging. For example, a Li-ion battery fabricated using the anode reveals a stable capacity of 260 mAh g-1 consistently after coupling with a standard cathode like lithium in an electrolyte of LiPF6 in ethylene carbonate (EC) and dimethyl carbonate (DMC).