近日，英国剑桥大学Baumberg, Jeremy J.团队揭示了在氧化还原反应过程中，瞬态Au-Cl层调节金纳米颗粒的表面化学性质。2025年11月13日出版的《自然-化学》杂志发表了这项成果。

在纳米尺度上控制表面化学对于稳定等离激元、催化和传感系统的结构及调控功能至关重要——即便痕量配体或离子也能重塑表面电荷与反应活性。然而，在工况条件下探测此类动态界面仍存在挑战，这制约了精密纳米材料的设计开发。

研究组通过原位表面增强拉曼光谱，识别出电化学循环过程中在金界面形成的瞬态Au-Cl吸附层。该吸附层表现出金与氯之间的显著电荷转移，产生具有外向偶极的电场，可极化邻近原子并调控局部电势。这种偶极效应不仅能稳定纳米间隙界面，引导配体定向重结合，从而实现亚纳米结构的可逆重构，还能改变界面电荷分布，介导不同金氧化态之间的电子转移，发挥氧化还原活性中间体的作用。这些发现揭示了瞬态表面物种如何调控纳米尺度反应活性与稳定性，为设计催化剂、传感器及纳米材料提供了新策略。

附：英文原文

Title: Transient Au–Cl adlayers modulate the surface chemistry of gold nanoparticles during redox reactions

Author: Sibug-Torres, Sarah May, Niihori, Marika, Wyatt, Elle, Arul, Rakesh, Spiesshofer, Nicolas, Jones, Tabitha, Graham, Duncan, de Nijs, Bart, Scherman, Oren A., Rao, Reshma R., Ryan, Mary P., Squires, Alexander, Savory, Christopher N., Scanlon, David O., Daaoub, Abdalghani, Sangtarash, Sara, Sadeghi, Hatef, Baumberg, Jeremy J.

Issue&Volume: 2025-11-13

Abstract: Controlling surface chemistry at the nanoscale is essential for stabilizing structure and tuning function in plasmonic, catalytic and sensing systems, where even trace ligands or ions can reshape surface charge and reactivity. However, probing such dynamic interfaces under operando conditions remains challenging, limiting efforts to engineer nanomaterials with precision. Here, using in situ surface-enhanced Raman spectroscopy, we identify a transient Au–Cl adlayer that forms during electrochemical cycling at gold interfaces. The adlayer exhibits significant charge transfer between gold and chlorine, generating an outward-facing dipole that polarizes neighbouring atoms and modulates the local potential. This dipole stabilizes nanogap interfaces and directs oriented ligand rebinding, enabling reversible reconstruction of subnanometre architectures. It also alters interfacial charge distributions and mediates electron transfer between gold oxidation states, acting as a redox-active intermediate. These findings show how transient surface species shape nanoscale reactivity and stability, offering strategies for designing catalysts, sensors and nanomaterials.

DOI: 10.1038/s41557-025-01989-4

Source: https://www.nature.com/articles/s41557-025-01989-4