厦门大学吴德印团队报道了对氨基苯甲酸在纳米金电极上的等离子体光电化学偶联反应。相关研究成果发表在2022年2月24日出版的《美国化学会杂志》。

表面等离子体激元共振（SPR）通过在等离子体金属纳米结构（PMNs）的表面电子对光的吸收和限制之间提供有效的相互作用，架起了光子学和光电化学的桥梁。在表面增强拉曼光谱（SERS）中，表面等离子体共振（SPR）极大地增强了拉曼强度，导致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，研究人员研究了对氨基苯甲酸（PABA）在纳米结构金电极上的SPR光电化学反应。将PABA吸附在PMN修饰的金电极上，得到了头尾偶联产物“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p，p′-偶氮二苯甲酸酯（ADBA）。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，在基本条件下，主要产品为ADBA，次要产品为ICBA。研究人员还提供了足够的证据，证明尾对尾偶合反应产物在非水介质而不是水介质中发生氧化。

上述发现通过循环伏安法、SERS和可能的反应中间体，即4-氨基苯二胺、4-羟基苯二胺和联苯胺的理论计算结果得到验证。理论吸附模型和实验结果表明，PABA以对氨基苯甲酸盐的形式吸附在金团簇上，呈双齿构型。

研究工作为PMN选择性表面催化偶联反应的调控提供了新的视角，有利于光电化学界面上的热载流子转移效率。

附：英文原文

Title: Plasmonic Photoelectrochemical Coupling Reactions of para-Aminobenzoic Acid on Nanostructured Gold Electrodes

Author: Rajkumar Devasenathipathy, Jia-Zheng Wang, Yuan-Hui Xiao, Karuppasamy Kohila Rani, Jian-De Lin, Yi-Miao Zhang, Chao Zhan, Jian-Zhang Zhou, De-Yin Wu, Zhong-Qun Tian

Issue&Volume: February 24, 2022

Abstract: 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 para-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 p,p′–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 para-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.

DOI: 10.1021/jacs.1c10447

Source: https://pubs.acs.org/doi/10.1021/jacs.1c10447