电化学沉积Rh制备紫外拉曼活性基底

Rh在紫外激发区间有着较强的表面增加拉曼散射(SERS).用循环伏安法研究了RhCl3溶液中Rh3 在Au电极上的电化学还原行为,用恒电位阶跃法在Au基底上制备了Rh沉积层,并用场发射扫描电子显微镜、能谱及电化学方法对得到的沉积层进行了表征.结果表明,在所选择的电位下用电沉积方法能够在金表面得到均匀的Rh沉积层,该沉积层保持了金属Rh原有的电化学特性.采用电化学方法通过先粗糙Au电极再沉积Rh的策略,可以制备粗糙的Rh表面作为紫外SERS基底.拉曼光谱实验表明,以吡啶为探针分子,该基底具有很好紫外SERS活性.

Electrochemical deposition of Rh as an active UV-SERS substrate

The transition metal Rh is highly active in surface-enhanced Raman scattering (SERS) under ultraviolet activation. The electrochemical deposition behavior of Rh3 on Au electrode was studied using cyclic voltammetry (CV) and a layer of Rh was prepared on Au substrate by constant potential step method. Scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and electrochemical method were employed to characterize the Rh layer. The experimental results show that a uniform Rh layer has been obtained on Au surface. Electrochemical measurements demonstrate that the resulting Rh layer exhibits the same electrochemical properties as those of bulk Rh in sulfuric solution. The rough Rh substrate was prepared by using the following strategy: firstly, a rough Au substrate was prepared by electrochemical method, and then a layer of Rh was electrochemically deposited on the rough Au surface. The obtained Rh film has the roughness similar to that of Au substrate and exhibits good SERS activity when using pyridine as the probe molecule.