Irradiated Graphene Loaded with SnO₂ Quantum Dots for Energy Storage

Tin dioxide (SnO₂) and graphene are unique strategic functional materials with widespread technological applications, particularly in the areas of solar batteries, optoelectronic devices, and solid-state gas sensors owing to advances in optical and electronic properties. Versatile strategies for microstructural evolution and related performance of SnO₂ and graphene composites are of fundamental importance in the development of electrode materials. Here we report that a novel composite, SnO₂ quantum dots (QDs) supported by graphene nanosheets (GNSs), has been prepared successfully by a simple hydrothermal method and electron-beam irradiation (EBI) strategies. Microstructure analysis indicates that the EBI technique can induce the exfoliation of GNSs and increase their interlayer spacing, resulting in the increase of GNS amorphization, disorder, and defects and the removal of partial oxygen-containing functional groups on the surface of GNSs. The investigation of SnO₂ nanoparticles supported by GNSs (SnO₂/GNSs) reveals that the GNSs are loaded with SnO₂ QDs, which are dispersed uniformly on both sides of GNSs. Interestingly, the electrochemical performance of SnO₂/GNSs indicates that SnO₂ QDs supported by a 210 kGy irradiated GNS shows excellent cycle response, high specific capacity, and high reversible capacity. This novel SnO₂/GNS composite has potential practical applications in SnO₂ electrode materials during Li⁺ insertion/extraction.