McHardy J, Robblee L S, Marston J M, Brummer S B
Biomaterials. 1980 Jul;1(3):129-34. doi: 10.1016/0142-9612(80)90034-4.
Trace analysis has shown that Pt electrodes can suffer appreciable dissolution when used to apply biphasic current pulses of the type used in neural stimulation. The dissolution occurs even under conditions where other irreversible faradaic reactions, e.g., H2O electrolysis, are avoided. In the present study, factors influencing the dissolution of Pt electrodes during biphasic pulsing in neutral inorganic saline have been examined. The findings are consistent with the behaviour of Pt electrodes reported in other inorganic media. In a given test, the quantity of Pt dissolved was found to be a linear function of the aggregate anodic or cathodic charge injected. Therefore, dissolution 'rates' can be conveniently expressed in terms of nanograms of Pt per coulomb injected, e.g., 100 ng C-1. Most of the Pt went into solution as Pt (II) species, so the above rate would correspond approximately to 100 p.p.m. of the anodic charge per pulse. For anodic-first (AF) pulses, charge density was the major factor controlling dissolution, whereas for cathodic-first (CF) pulses, pulse duration had the greater influence. Depending on the polarity (AF or CF), charge density, and duration of the biphasic pulse, the dissolution rate for smooth bead electrodes ranged from 30 to 300 ng C-1. Lower rates were achieved with platinized electrodes but in the absence of organic solutes, it is unlikely that Pt dissolution can be completely suppressed.
痕量分析表明，当用于施加神经刺激中使用的那种双相电流脉冲时，铂电极会发生明显的溶解。即使在避免其他不可逆的法拉第反应（例如水电解）的条件下，溶解仍会发生。在本研究中，研究了中性无机盐溶液中双相脉冲期间影响铂电极溶解的因素。这些发现与其他无机介质中报道的铂电极行为一致。在给定的测试中，发现溶解的铂量是注入的总阳极或阴极电荷量的线性函数。因此，溶解“速率”可以方便地表示为每注入一库仑的铂纳克数，例如100 ng C-1。大部分铂以Pt(II) 物种的形式进入溶液，因此上述速率大约相当于每个脉冲阳极电荷量的100 ppm。对于阳极优先 (AF) 脉冲，电荷密度是控制溶解的主要因素，而对于阴极优先 (CF) 脉冲，脉冲持续时间的影响更大。根据双相脉冲的极性（AF 或 CF）、电荷密度和持续时间，光滑珠状电极的溶解速率范围为30至300 ng C-1。镀铂电极的溶解速率较低，但在没有有机溶质的情况下，铂的溶解不太可能被完全抑制。
