Facile synthesis of hollow SnO2 nanospheres uniformly coated by Ag for electro-oxidation of hydrazine

Novel Ag/SnO2 has been synthesized by a facile two-step method using hollow SnO2 nanospheres as support. Firstly, monodispersed SnO2 hollow nanospheres have been obtained by solvothermal (ethanol/water) method. X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) show that hollow SnO2 nanospheres exhibit good crystalline and monodispersion with the diameter ranging from 200 to 400 run. Secondly, Ag/SnO2 nanospheres have been prepared by a facile reduction in silver ammonia solution. XRD and selected area electron diffraction (SAED) confirm the formation of Ag in Ag/SnO2 nanospheres. SEM and TEM show the homogeneous coating of Ag nanoparticles on hollow SnO2 nanospheres. SEM mapping images confirm the uniform distribution of Ag element on SnO2 nanospheres. The electrocatalytic measurements for hydrazine electro-oxidation have been conducted. The results show that Ag/SnO2 nanospheres have excellent electrocatalytic activity with-0.12 V (vs. SCE) at the scan rate of 20 mV s(-1). The hollow structure of SnO2 nanospheres can provide shorter distance of electron transport and better dispersion of Ag nanoparticles, which can be responsible for the enhanced conductivity and efficient utilization of active sites.