State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), Xiamen University, Xiamen 361005, China.
J Am Chem Soc. 2022 Mar 9;144(9):3821-3832. doi: 10.1021/jacs.1c10447. Epub 2022 Feb 24.
Surface plasmon resonance (SPR) bridges photonics and photoelectrochemistry by providing an effective interaction between absorption and confinement of light to surface electrons of plasmonic metal nanostructures (PMNs). SPR enhances the Raman intensity enormously in surface-enhanced Raman spectroscopy (SERS) and leads to the plasmon-mediated chemical reaction on the surface of nanostructured metal electrodes. To observe variations in chemical reactivity and selectivity, we studied the SPR photoelectrochemical reactions of -aminobenzoic acid (PABA) on nanostructured gold electrodes. The head-to-tail coupling product "4-[(4-imino-2,5-cyclohexadien-1-ylidene)amino]benzoic acid (ICBA)" and the head-to-head coupling product ,'-azodibenzoate (ADBA) were obtained from PABA adsorbed on PMN-modified gold electrodes. In particular, under acidic and neutral conditions, ICBA was obtained as the main product, and ADBA was obtained as the minor product. At the same time, under basic conditions, ADBA was obtained as the major product, and ICBA was obtained as the minor product. We have also provided sufficient evidence for the oxidation of the tail-to-tail coupling reaction product that occurred in a nonaqueous medium rather than in an aqueous medium. The above finding was validated by the cyclic voltammetry, SERS, and theoretical calculation results of possible reaction intermediates, namely, 4-aminophenlylenediamine, 4-hydroxyphenlylenediamine, and benzidine. The theoretical adsorption model and experimental results indicated that PABA has been adsorbed as -aminobenzoate on the gold cluster in a bidentate configuration. This work offers a new view toward the modulation of selective surface catalytic coupling reactions on PMN, which benefits the hot carrier transfer efficiency at photoelectrochemical interfaces.
表面等离子体激元共振（SPR）通过将光的吸收和限制有效地结合到等离子体金属纳米结构（PMN）的表面电子中，将光子学和光电化学联系起来。SPR 在表面增强拉曼光谱（SERS）中极大地增强了拉曼强度，并导致在纳米结构金属电极表面发生等离子体介导的化学反应。为了观察化学反应性和选择性的变化，我们研究了 -氨基苯甲酸（PABA）在纳米结构金电极上的 SPR 光电化学反应。头对头偶联产物“4-[(4-亚氨基-2,5-环己二烯-1-亚基)氨基]苯甲酸（ICBA）”和头尾偶联产物，'-偶氮二苯甲酸盐（ADBA）是从吸附在 PMN 修饰的金电极上的 PABA 获得的。特别是在酸性和中性条件下，ICBA 是主要产物，ADBA 是次要产物。同时，在碱性条件下，ADBA 是主要产物，ICBA 是次要产物。我们还提供了充分的证据证明在非水介质中而不是在水介质中发生了尾对尾偶联反应产物的氧化。这一发现得到了循环伏安法、SERS 和可能反应中间体的理论计算结果的验证，即 4-氨基苯二胺、4-羟基苯二胺和联苯。理论吸附模型和实验结果表明，PABA 以 -氨基苯甲酸的形式在金簇中以双齿构型被吸附。这项工作为 PMN 上选择性表面催化偶联反应的调制提供了新的视角，这有利于光电化学界面处热载流子转移效率。
