在以1,3-二羟甲基-5,5 '-二甲基乙内酰脲(DMDMH)为配位剂的镀液体系中研究了金的电沉积工艺和电结晶行为.循环伏安曲线测试中,在-0.88 V附近出现了金的阴极还原峰,在一定的正向电势扫描区间内没有阳极氧化峰出现.计时电流法研究表明,金在玻碳电极上的电结晶过程符合三维连续成核生长模式.SEM和AFM观察表明,在DMDMH体系中获得的镀金层比DMH体系获得的镀金层结晶更为细小,平整性更好.XRD测试表明,在两种镀液体系中获得的镀金层都沿着(111)晶面择优生长.DMDMH镀液体系稳定性能良好.%Electrodeposition and electrocrystallization behavior of gold from a cyanide-free bath with DMDMH as complexing agent had been investigated in this paper. The results of cyclic voltammogram showed that a single cathodic reduction wave at -0.88 V corresponded to the reduction of Au(Ⅲ) to Au, and no anodic oxidation wave was observed on the certain positive scan field. Chronoamperometric results indicated that the electrodeposition of metallic Au on glass carbon electrode (GCE) belonged to a three dimensional (3D) progressive nucleation mechanism. The results of SEM and AFM showed that the grains obtained in bath using DMDMH-gold complex was smaller and exhibited better flattening capability than the grains obtained in bath using DMH-gold complex. The XRD results indicated that the gold electrodeposits plated in the baths both had a preferential orientation along (111) direction. The gold plating bath with DMDMH as complexing agent exhibited good stability.
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