Shape-controlled bismuth nanoflakes as highly selective catalysts for electrochemical carbon dioxide reduction to formate
Shape-controlled bismuth nanoflakes as highly selective catalysts for electrochemical carbon dioxide reduction to formate
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DOI：
10.1016/j.nanoen.2017.05.065
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发表时间：
2017-09-01
期刊：
影响因子：
17.6
通讯作者：
Lee, Jong-Lam
中科院分区：
文献类型：
--
作者：
Kim, Sungjoo;Dong, Wan Jae;Lee, Jong-Lam
采用脉冲电沉积的新方法，设计并在Cu衬底上直接生长纳米结构的铋（Bi）纳米片。与传统的直流电沉积铋膜相比，铋纳米片具有大量的边缘和角点。数值模拟证明，纳米结构的尖锐边缘或角点形成强大的局部电场，从而提高了水溶液中CO2的电化学还原活性。在-0.4 V-RHE的低电位下，Bi纳米片表现出较高的HCOO-法拉第效率（FE = 79.5%），在-0.6 V-RHE时达到了接近100%的最大FE，这意味着Bi电催化剂的形状控制确实是降低HCOO-生产电耗的有效方法。在0.1 M KHCO3水溶液中，铋纳米片在10 h内保持稳定。结果表明，调整纳米结构是开发一种高性能的无贵金属水溶液电化学还原CO2电催化剂的关键。
Nanostructured bismuth (Bi) nanoflakes were designed and directly grown on Cu substrate using a novel pulse electrodeposition method. Compared with conventional bismuth film grown by direct current electrodeposition, Bi nanoflakes have large number of edge and corner sites. As it has been proven by numerical simulation, sharp edge or corner sites of the nanostructures form strong local electric fields, which boost the catalytic activity for the electrochemical reduction of CO2 in aqueous solution. The Bi nanoflakes showed a high HCOO- faradaic efficiency (FE = 79.5%) at low potential of -0.4 V-RHE and achieved a maximum FE close to 100% at -0.6 V-RHE, meaning that the shape control of Bi electrocatalyst is indeed an efficient way to reduce the electrical power consumption for HCOO- production. Moreover, Bi nanoflakes were stable during 10 h operation in 0.1 M KHCO3 aqueous solution. The results suggest that tailoring the nanostructure is a key in developing a high performance noble-metal-free electrocatalyst for electrochemical CO2 reduction in aqueous solution.