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应用循环伏安法和电位阶跃法研究了Ni-W合金电沉积特点.结果表明,在以柠檬酸铵为络合剂的镀液中,沉积层的W含量随电流密度的增大而增加但电流效率变化不大,当电流密度超过15A/dm2后,镀层的W含量不再发生明显的变化而电流效率却明显降低.循环伏安实验结果表明,当镀液中有Ni2+存在时,WO2-4才能被还原到以Ni-W合金形式存在的W金属态,且其沉积电位比WO2-4(沉积为钨蓝氧化物)和Ni2+单独沉积时的电位更正.根据电位阶跃的i~t曲线分析得知,在玻碳电极上Ni-W合金电结晶过程遵从扩散控制瞬时成核三维成长模式进行,且随着过电位的增加,电极表面上晶核数增多.
The characteristics of electrodeposition of Ni-W alloy were studied by cyclic voltammetry and potential step method. The results showed that the W content of the deposited layer increased with the increase of the current density, but the current efficiency did not change much. When the current density exceeded 15 A / dm2, the W content of the coating No significant changes occur and the current efficiency is significantly reduced. Cyclic voltammetry results show that when Ni2 + is present in the bath, WO2-4 can be reduced to the W metal state in the form of Ni-W alloy and its deposition potential is lower than that of WO2-4 (deposited as tungsten blue oxide ) And potential correction when Ni2 + was deposited alone. According to the i ~ t curve analysis of potential step, it is found that the electrocrystallization of Ni-W alloy on glassy carbon electrode follows diffusion-controlled three-dimensional growth mode of instantaneous nucleation. With the increase of overpotential, the number of nuclei increase.