Effect of Granularity on Anti-Oxidizing Ability of Copper Nano-Powder

Taken KBH4 and vitamin C (VC) as reducers, CuSO4·5H2O as raw material, EDTA as complex agent and polyvinyl-pyrolidone (PVP) as protector, the copper nano-powder was prepared by the liquid reduction method. Placed the powders with different granularities in the air for a certain time, then the powders were examined by XRD. The results reveal that the anti-oxidizing ability depends on the granularity of the copper nano-powder: when the granularity of the copper nano-powder is bigger, the anti-oxidizing ability is better. If the granularity of the powder is bigger than 75nm, the powder is not easily oxidized in the air. The 75nm copper nano-powder samples begin to be oxidized at above 120°C. The melting point of the copper nano-powder is very low, so the particle will melt and grow up quickly when it is hit by the TEM electron clusters.