Environmentally Friendly and Cost-Effective Synthesis of Carbonaceous Particles for Preparing Hollow SnO2 Nanospheres and their Bifunctional Li-Storage and Gas-Sensing Properties.

The templated preparation of hollow nanomaterials has received broad attention. However, many templates are expansive, environmentally-harmful, along with involving a complicated preparation process. Herein, we present a cost-effective, environmentally friendly and simple approach for making carbonaceous particles which have been demonstrated as efficient templates for preparing hollow nanospheres. Natural biomass, such as wheat or corn, is used as the source only, and thus other chemicals are not needed. The carbonaceous particles possess abundant hydroxyl and carboxyl groups, enabling them to efficiently adsorb metal ions in solution. The prepared SnO₂ hollow spheres were used in a lithium-ion (Li-ion) battery anode, and as the sensing layer of a gas sensor, respectively. After charge–discharge for 200 times at a rate of 1 C, the anodes exhibit a stable capacity of 500 mAh g⁻¹, and a Coulombic efficiency as high as 99%. In addition, the gas sensor based on the SnO₂ hollow spheres shows a high sensing performance towards ethanol gas. It is expected that the presented natural biomass-derived particles and their green preparation method will find more applications for broad research fields, including energy-storage and sensors. [ABSTRACT FROM AUTHOR]