Process intensification of uniform loading of SnO2 nanoparticles on graphene oxide nanosheets using a novel ultrasound assisted in situ chemical precipitation method

Abstract

In this paper, a novel ultrasound assisted, solution-based chemical synthesis method for the preparation of SnO2–graphene nanocomposite is presented. Graphene oxide (GO) was prepared by the modified Hummers–Offeman method in presence of ultrasonic irradiation. Further loading of SnO2 on GO was carried out with an ultrasound assisted solution-based synthesis route. The prepared GO and SnO2–graphene nanocomposite were characterized by XRD, TEM, FTIR spectra, TGA and DTA analysis in order to confirm the formation of graphene–SnO2 nanocomposite. TEM analysis of ultrasonically prepared graphene–SnO2 composite shows the uniform and fine loading of SnO2 particles (3–5nm) on graphene nanosheets. However agglomerated morphology was observed in case of conventionally prepared graphene–SnO2 composite. The cavitational effects generated due to the ultrasonic irradiations during the synthesis of graphene–SnO2 composite improve the fine and uniform loading of SnO2 on graphene nanosheets by oxidation–reduction reaction between GO and SnCl2·2H2O compared to conventional synthesis methods. The formed material was used for the preparation of anode in lithium ion batteries and its electrochemical performance was characterized by cyclic voltammetry and charge/discharge cycles. It is found that the capacity of SnO2–graphene nanocomposite based Li-battery is stable for around 120 cycles, and the battery could repeat stable charge–discharge reaction.