In a paper to be published in the forthcoming issue in NANO, a group of researchers led by Wei Zhang from the Yunnan Minzu University, China have developed a simple, low cost and eco-friendly method to synthesize SnO2 nanorods for lithium ion batteries.
Tin dioxide (SnO2) is an important N-type semiconductive material with the advantage of stable, large band gap, low cost, and Eco-friendly. SnO2 has wide applications in many areas such as solar cell, gas sensor, and optoelectronic device. One-dimensional SnO2 nano structures such as nanorod and nanowire have excellent optical and electrical properties and large surface-to-volume ratio. These provide unique advantages in many fields such as electrode material, photovoltaic devices, photocatalysis, and surface adsorption. However, most of the reported methods to synthesis SnO2 nanorods usually require high temperature or other strict experimental conditions.
In this study, the researchers successfully prepared SnO2 nanorods by simple template-free hydrothermal method without surfactant. During the reaction process, SnO intermediate with lamellar morphology is first formatted by hydrothermal method and SnO2 nanorods are obtained after calcinations. The results of XRD characterization show that the lamellar structured SnO intermediate has a preferred orientation in the 001 direction. According to the mechanism used during the possible formation processes of the SnO2 nanorods, first, tiny crystal nucleus of Sn(OH)2 and a bit of SnCO3 generates from SnCl2 and urea. Then the crystal nucleus gather to form a nanorod. With continued reaction, nanorods form sheets and the sheets grow up to lamellar morphology and intermediate decomposes into SnO because of hydrothermal process. The SnO intermediate converts to SnO2 with the sheets breaking into nanorods after calcinations. The SnO2 nanorods have an average width of approximately 44.4 nm and an average length of 213.8 nm at the hydrothermal reaction temperature 150°C for 24 h, the aspect ratio of this SnO2 nanorod is approximately 4.9; When the hydrothermal temperature increases to 180°C, a regular SnO2 nanorod shape with 45-50 nm width and 150-190 nm length is obtained, the aspect ratio of this SnO2 nanorod is about 3.5. Both the rod-like nanomaterial used as anode materials for lithium-ion battery exhibited high initial discharge specific capacity up to 1600 mAh g-1 at 0.2 C rate.
Financially supported from National Natural Scientific Fund of China (No.21761035, No.21463028, No.21565031, No.21665027), Key Project of Higher Education Research Foundation in Hebei Province (grant: ZD2019106), the Doctoral Scientific Research Foundation of North China Institute of Aerospace Engineering (No. BKY-2018-01), Innovative Training Program of Yunnan Minzu University for graduate student (No.2018YJCXS249) are acknowledged.
Corresponding author for this study is Dr Lili Feng from the North China Institute of Aerospace Engineering.
For more insight into the research described, readers are invited to access the paper on NANO.
Caption: SnO intermediate with lamellar morphology is first formatted by hydrothermal method and SnO2 nanorods are obtained after calcinations.
NANO is an international peer-reviewed monthly journal for nanoscience and nanotechnology that presents forefront fundamental research and new emerging topics. It features timely scientific reports of new results and technical breakthroughs and publishes interesting review articles about recent hot issues.