氯离子对铜在玻碳电极上电结晶的影响

Effect of Chloride Ion on Electrocrystallization of Copper on Glass Carbon Electrode

采用线性扫描伏安法和计时安培法研究了硫酸铜溶液中铜在玻碳电极上电结晶的初期行为 .在含与不含氯离子的 0 0 5mol·L-1CuSO4 0 5mol·L-1H2 SO4电解液中 ,循环伏安实验结果表明铜在玻碳基体上的沉积没有经过UPD过程 ;氯离子明显使Cu的沉积和氧化峰变得尖锐 ,促进Cu的沉积速度 .计时安培实验结果表明 ,Cu的电结晶按瞬时成核和三维生长方式进行 .氯离子不改变Cu的电结晶机理 ,但在I～t曲线中 ,导致电流达最大 (Im)所需的时间tm 减小、晶核数密度和生长速度增大 ,从而明显改变Cu沉积层的质量 .当Cl-浓度在 10～ 2 0mg·L-1范围内 ,成核的晶核数密度达较大 ,即氯离子的最适宜添加量 .

The initial stage of copper electrodeposition and the influence of chloride ions on the nucleation and growth of copper on glass carbon from acid sulphate solution were studied by using the cyclic voltammetry and the chronoamperometry method. Instantaneous nucleation with three dimensional growth is found for the solutions either with or without chloride. Obviously, chloride ions increase the nucleation rate and the nuclear number density of nuclei at the surface. Since the deposits are smooth, bright at high nuclear number densities, it can be concluded that chloride ions effectively promote the smooth and brightness of surface. The higher nuclear number densities are obtained at 10～20 mg·L -1 of chloride ions. Maintaining the optimum level chloride ion concentration is beneficial to electrodeposits.