高等学校化学学报

高等学校化学学报 ›› 1998, Vol. 19 ›› Issue (10): 1640.

• 论文 • 上一篇    下一篇

硫脲在HNO3介质中共吸附行为的喇曼光谱研究

钟起玲1, 刘峰名2, 邹道文1, 施财辉2, 谢泳2, 田中群2   

  1. 1. 江西师范大学化学系, 南昌, 330027;
    2. 厦门大学固体表面物理化学国家重点实验室、化学系、物理化学研究所, 厦门, 361005
  • 收稿日期:1997-09-16 出版日期:1998-10-24 发布日期:1998-10-24
  • 通讯作者: 钟起玲,男,49岁,副教授.
  • 作者简介:钟起玲,男,49岁,副教授.
  • 基金资助:

    国家自然科学基金(批准号:29463010)、江西省自然科学基金和厦门大学固体表面物理化学国家重点实验室资助课题.

Raman Spectroscopic Studies on Coadsorption of Thiourea in the Nitric Acid Medium

ZHONG Qi-Ling1, LIU Feng-Ming2, ZOU Dao-Wen1, SHI Cai-Hui2, XIE Yong2, TIAN Zhong-Qun2   

  1. 1. Department of Chemistry, Jiangxi Normal University, Nanchang, 30027;
    2. State Key Laboratory for Physical Chemistry of Solid Surfaces, Department of Chemistry, Institute of Physical Chemistry, Xiamen University, Xiamen, 361005
  • Received:1997-09-16 Online:1998-10-24 Published:1998-10-24

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摘要： 用常规Raman谱、电化学现场表面增强喇曼散射光谱(SERS)和时间分辨SERS光谱(TRSERS)研究了硫脲(TU)在HNO3介质中与NO-3的共吸附行为.实验结果表明,NO3-离子能被TU诱导共吸附在其质子化氨基上;TU以S端按σ配位键方式化学吸附在银电极表面.在较正电位区间(≥-0.6V),TU垂直吸附,电位负移(≤-0.8V),TU由垂直逐渐转变为倾斜甚至平躺吸附;在较负的电位下(≤-0.8V),TU在HNO3介质中比在HClO4中更稳定,甚至在-2.0V的电位下亦能检测到TU的SERS信号.

关键词: 硫脲, 硝酸根离子, 共吸附, SERS, TRSERS

Abstract: The coadsorption of thiourea(TU) with NO3- in aqueous HNO3 was studied by using normal Raman spectroscopy(NRS), surface enhanced Raman scattering spectroscopy(SERS) and time resolved SERS(TRSERS). It was found that TUis chemically adsorbed on the surface of silver electrode via S, and NO3- can be induced by TUand coadsorbed on the electrode through the protonated amino of TUin the solution containing HNO3. The experimental results show that, at the potentials more positive than -0.6 V, TUis vertically adsorbed on the surface, while when the electrode potential goes negatively it gradually tends to tilt, even flat. Acomparative study on the stability of TUadsorbed on the silver surface in the medium of HNO3 and HClO4 respectively was carried out. It indicates that TUis more stable in aqueous HNO3 than in aqueous HClO4 at the relatively negative potentials(<-0.8 V), consequentially, the SERSsignal of TUcan still be detected in aqueous HNO3 at the potential of -2.0 Vwhile it is out of detection even at -1.4 Vin the latter medium. The origin has been discussed in detail in this paper.

Key words: Thiourea, Nitrate ion, Coadsorption, SERS, TRSERS

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