Solid‐state dewetting is the heat‐induced agglomeration of thin metal films into defined nanoparticles (NPs). Dewetted Pt nanoparticles are investigated on F‐doped SnO2 (FTO) substrates as model binder‐free electrodes for the hydrogen evolution reaction (HER). Dewetting of Pt films into particles exposes the FTO substrate and the metal/support (Pt‐FTO) contact line. Despite the decrease in Pt electrochemical surface area (ECSA) upon dewetting, dewetted NPs show a >3‐fold increase in ECSA‐normalized HER activity compared to as‐deposited nanocrystalline Pt films. Electrodes designed with dewetted Pt NPs of different sizes show that the HER activity does not only correlate with the ECSA but also increases with increasing the Pt‐FTO contact line length. The smaller the NPs, the larger the Pt‐FTO contact line, and the higher the activity. This effect is ascribed to electronic metal‐support interaction (EMSI), due to electron transfer from FTO to Pt. It is proposed that EMSI effects alter the electronic structure of Pt sites near the Pt‐FTO contact line, facilitating the H2 evolution kinetics. When NPs are a few nm‐sized, a large mass fraction of Pt is affected by EMSI, resulting in a further increase of HER activity compared to NPs ≥10 nm despite the lower ECSA.

中文翻译：

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由于电子金属-载体相互作用，Pt 纳米颗粒的去湿促进了电催化析氢

固态去湿是指金属薄膜在热作用下聚集成特定的纳米粒子（NP）。在氟掺杂 SnO 上研究去湿 Pt 纳米颗粒2（FTO）基板作为析氢反应（HER）的无粘合剂电极模型。 Pt 薄膜去湿成颗粒，暴露出 FTO 基底和金属/支撑（Pt-FTO）接触线。尽管去湿后 Pt 电化学表面积 (ECSA) 减少，但与沉积的纳米晶 Pt 薄膜相比，去湿后的 NP 的 ECSA 归一化 HER 活性增加了 3 倍以上。使用不同尺寸的去湿 Pt NP 设计的电极表明，HER 活性不仅与 ECSA 相关，而且随着 Pt-FTO 接触线长度的增加而增加。 NPs越小，Pt-FTO接触线越大，活性越高。这种效应归因于电子金属载体相互作用（EMSI），这是由于电子从 FTO 转移到 Pt。据认为，EMSI 效应改变了 Pt-FTO 接触线附近 Pt 位点的电子结构，促进了 H2进化动力学。当纳米颗粒尺寸为几纳米时，大部分 Pt 会受到 EMSI 的影响，尽管 ECSA 较低，但与≥10 nm 的纳米颗粒相比，HER 活性进一步增加。