Success and failure in the incorporation of gold nanoparticles inside ferri/ferrocyanide thermogalvanic cells
Success and failure in the incorporation of gold nanoparticles inside ferri/ferrocyanide thermogalvanic cells
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DOI：
10.1016/j.elecom.2019.03.007
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发表时间：
2019-05-01
影响因子：
5.4
通讯作者：
Aldous, Leigh
中科院分区：
文献类型：
--
作者：
Alzahrani, Hassan A. H.;Buckingham, Mark A.;Aldous, Leigh
热电偶系统代表了一种仅使用氧化还原化学将温度梯度转换为电力的方法。然而，氧化还原对的电子转移和物理传质的动力学是已知的限制。在这项研究中，我们提出了自包含的凝胶热原电池（或热电池）含有铁氰化物/亚铁氰化物氧化还原对，其中另外有金纳米粒子固定在凝胶/电极界面，或分布在整个凝胶。这两种方法引入的金纳米粒子的结果在一个明显的电催化性能的改善，所证明的电子转移电阻显着降低。然而，当用作热原电池时，在发电方面仅观察到微小的改进，并且观察到金纳米颗粒相对快速的溶解，以产生普鲁士蓝的钝化金类似物。因此，成功的制备和短期改善已得到证实，但被长期稳定性问题所抵消。在铁氰化物/亚铁氰化物的存在下，特别是在热电偶条件下，通常惰性的金纳米颗粒的相对令人惊讶的不稳定性是特别值得注意的。
Thermogalvanic systems represent a means to convert a temperature gradient into electricity, using only redox chemistry. However, the kinetics of electron transfer and physical mass transport of the redox couples are known limitations. In this study we present self-contained gelled thermogalvanic cells (or thermocells) containing the ferricyanide/ferrocyanide redox couple, which additionally have gold nanoparticles either immobilised at the gel/electrode interface, or distributed throughout the entire gel. Both methods of introducing the gold nanoparticles result in an apparent electrocatalytic improvement, as demonstrated by significant decreases in the electron transfer resistance. However, when used as thermogalvanic cells, only minor improvements were observed in power generation, and relatively rapid dissolution of the gold nanoparticles was observed, to yield passivating gold analogues of Prussian blue. Therefore successful preparation and short-term improvements have been demonstrated, but are offset by long-term stability issues. The relatively surprising instability of the generally inert gold nanoparticles in the presence of ferricyanide/ferrocyanide, particularly under thermogalvanic conditions, is of particular note.