A new type of nanoelectrode, nanoporous platinum (NPt) electrode was prepared on aluminum oxide membrane by thermal evaporation deposition. The morphology, conductivity and electrocatalytic activity of NPt electrode were characterized and compared with those of nanofilm-Pt electrode through scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) techniques, respectively. SEM images showed that "nanocavities" observed in NPt electrode were actually 2-dimensional enclosures by linked nanoparticles. It was different from the conventional arrays of "nanocavities" formed on homogeneous metal films. EIS data indicated that NPt electrode possesses higher conductivity. Compared with that on nanofilm-Pt electrode (14.05 Ω·cm2), the impedance spectrum on NPt electrode exhibits a semicircle portion with much smaller diameters (1.24 Ω·cm2 for NPt-100, 1.48 Ω·cm2 for NPt-200). Meanwhile, the response sensitivity of NPt electrode to O2 is 0.85 mA cm-2, which is larger than that of nanofilm-Pt electrode (0.54 mA cm-2). The largest catalytic current for nitric oxide (NO) was obtained in buffer with pH value of 9.4 while for Angeli's salt (AS) was obtained in buffer with pH value of 5.4. Additionally, electrocatalytic mechanisms of NPt electrode toward NO and AS were proposed, which indicating it depended on pH value of buffer solution.

中文翻译：

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在阳极氧化铝膜上生长的纳米多孔铂电极：制备、表征、对活性氧和氮物种的电催化活性

通过热蒸发沉积在氧化铝膜上制备了一种新型纳米电极，纳米多孔铂（NPt）电极。分别通过扫描电子显微镜（SEM）、电化学阻抗谱（EIS）和循环伏安法（CV）技术表征了NPt电极的形貌、电导率和电催化活性，并与纳米膜-Pt电极进行了比较。SEM 图像显示，在 NPt 电极中观察到的“纳米腔”实际上是由连接的纳米颗粒构成的二维外壳。它不同于在均质金属薄膜上形成的传统“纳米腔”阵列。EIS 数据表明 NPt 电极具有更高的电导率。与纳米膜-Pt电极（14.05 Ω·cm2）相比，NPt 电极的阻抗谱呈现出直径更小的半圆部分（NPt-100 为 1.24 Ω·cm2，NPt-200 为 1.48 Ω·cm2）。同时，NPt电极对O2的响应灵敏度为0.85 mA cm-2，大于纳米膜-Pt电极（0.54 mA cm-2）。一氧化氮 (NO) 的最大催化电流在 pH 值为 9.4 的缓冲液中获得，而安吉利盐 (AS) 在 pH 值为 5.4 的缓冲液中获得最大催化电流。此外，还提出了NPt电极对NO和AS的电催化机制，表明它取决于缓冲溶液的pH值。一氧化氮 (NO) 的最大催化电流在 pH 值为 9.4 的缓冲液中获得，而安吉利盐 (AS) 在 pH 值为 5.4 的缓冲液中获得最大催化电流。此外，还提出了NPt电极对NO和AS的电催化机制，表明它取决于缓冲溶液的pH值。一氧化氮 (NO) 的最大催化电流在 pH 值为 9.4 的缓冲液中获得，而安吉利盐 (AS) 在 pH 值为 5.4 的缓冲液中获得最大催化电流。此外，还提出了NPt电极对NO和AS的电催化机制，表明它取决于缓冲溶液的pH值。