丙烯基硫脲与银电极表面相互作用的EQCM研究

运用循环伏安(CV)和电化学石英晶体微天平(EQCM)方法研究了酸性介质中银阳极溶出和阴极沉积过程以及丙烯基硫脲(ATU)对该过程的影响.实验结果表明:在酸性硝酸银溶液中,银阳极溶出和阴极沉积过程的实验测定值M w/n分别为18.3和43.4g/mol,尽管实验测定值与银1-电子过程的M w/n理论值(108g/mol)相差甚大,但考虑到酸性介质中氢电极过程的影响,仍可指认:在酸性AgNO3溶液中,银的阳极溶出和阴极沉积过程均为1-电子过程.在含有丙烯基硫脲(ATU)溶液中,Ag阳极溶出和阴极沉积过程的M w/n实验测定值分别为104.1和106.3 g/mol,与Ag的1-电子过程的M w/n理论值非常接近,指示丙烯基硫脲(ATU)并不改变银阳极溶出和阴极沉积过程的机理,但ATU阻化了氢的析出,促进了银的电极过程,加大了电极过程的可逆程度.本文从电极表面质量定量变化的角度提供了Ag阳极溶出和阴极沉积过程的新数据.

A EQCM Investigation of the Interaction of ATU with Silver Surface

The anodic dissolution and electrodeposition of Ag and effect of allyl thiourea(ATU)on the processes in acidic media have been investigated by using cyclic voltammetry(CV)and electrochemical quartz crystal microbalance(EQCM).The experimental results demonstrated that in acidic silver nitrate solution the Mw/n values of the anodic dissolution and electrodeposition of Ag were 18.3 and 43.4g/mol,respectively.Although there is a great difference between the experimental data and the theoretical Mw /n value for silver 1-electron process,in consideration of the effect of hydrogen electrode process,it could show that the anodic dissolution and electrodeposition of Ag are both corresponding to the 1-electron processes.The Mw /n values of the anodic dissolution and electrodeposition of Ag in the presence of ATU were 104.1 and 106.3 g / mol,respectively,which was close to 1-electron processes of Ag,indicating that ATU does not change the mechanism of silver anodic dissolution and electrodeposition.But it inhibits the production of hydrogen,accelerates silver electrode process,and increases the degree of reversibility of electrode process.The EQCM studies provide quantitative results of surface mass changes during electrodeposition and anodic dissolution of Ag,and have thrown new light in the elucidating electrodeposition and anodic dissolution of Ag.