Abstract: The SnO2/rGO and SnO2/rGO nano-composite was successfully synthesized by in-situ growing SnO2 nano-particles on GO with a mild hydrothermal method, using ammonium hydroxide as pH modifier to realize N doping of graphene, and the cell as well as catalytic performance of the two composites were investigated.The XRD and SEM results show that SnO2 particles disperse homogeneously on the surface of nitrogen doped graphene(N-rGO) and graphene(rGO) layers with the size of 50 nm and 100 nm respectively.Further TEM results indicate that the SnO2 particles are composed of smaller ones whose size range from 5 nm to 7 nm.The main half-cell test results can be concluded as follows, when the current density is 100 mA/g, the reversible capacities of SnO2/N-rGO and SnO2/rGO are 901 mAh/g and 756 mAh/g, respectively, which are 6.0 and 4.9 times higher than those of the pure SnO2 nanoparticles.The discharge capacities of SnO2/N-rGO and SnO2/rGO at 2 A/g are 619 mAh/g and 511 mAh/g, respectively, exhibiting an excellent rate performance.The electrochemical test proves that the catalytic performance for oxygen reduction reaction (ORR) of SnO2/N-rGO is significantly better than that of the SnO2/rGO and both exhibits a nearly four electron transfer process, providing a new direction for the non-platinum catalyst research.

Key words: The SnO2/rGO and SnO2/rGO nano-composite was successfully synthesized by in-situ growing SnO2 nano-particles on GO with a mild hydrothermal method, using ammonium hydroxide as pH modifier to realize N doping of graphene, and the cell as well as catalytic performance of the two composites were investigated.The XRD and SEM results show that SnO2 particles disperse homogeneously on the surface of nitrogen doped graphene(N-rGO) and graphene(rGO) layers with the size of 50 nm and 100 nm respectively.Further TEM results indicate that the SnO2 particles are composed of smaller ones whose size range from 5 nm to 7 nm.The main half-cell test results can be concluded as follows, when the current density is 100 mA/g, the reversible capacities of SnO2/N-rGO and SnO2/rGO are 901 mAh/g and 756 mAh/g, respectively, which are 6.0 and 4.9 times higher than those of the pure SnO2 nanoparticles.The discharge capacities of SnO2/N-rGO and SnO2/rGO at 2 A/g are 619 mAh/g and 511 mAh/g, respectively, exhibiting an excellent rate performance.The electrochemical test proves that the catalytic performance for oxygen reduction reaction (ORR) of SnO2/N-rGO is significantly better than that of the SnO2/rGO and both exhibits a nearly four electron transfer process, providing a new direction for the non-platinum catalyst research.