丁基黄药在CuO表面吸附的二维连续在线原位ATR-FTIR光谱研究

运用连续在线原位衰减全反射傅里叶变换红外光谱(ATR-FTIR)技术测定了纳米CuO表面对丁基黄药的吸附行为. 在FTIR 谱图中发现有峰的红移现象,吸收峰由1200 cm^-1偏移到1193 cm^-1,用超纯去离子水脱附,峰强度只有微小的变化,可判断丁基黄药在CuO表面发生了很强的化学吸附. 通过对吸附行为进行二维(2D)红外光谱分析,分辨出吸附过程中光谱强度的变化顺序. 二维异步相关光谱测定结果表明,1265 cm^-1处振动吸收峰最先引起光谱强度的变化,1265 cm^-1处吸收峰可归因为表面反应生成的双黄药和黄药分子聚集体的复合峰. 根据1200 cm^-1处黄药特征吸收峰强度的变化,进行吸附动力学模拟,得出CuO对丁基黄药的最大吸附量为529 mg·g^-1,且吸附符合拟二级吸附动力学过程.

Two-Dimensional Continuous Online In situ ATR-FTIR Spectroscopic Investigation of Adsorption of Butyl Xanthate on CuO Surfaces

In this study, a continuous online in situ attenuated total reflection Fourier- transform infrared (ATR-FTIR) spectroscopic technique was used to monitor the behavior of butyl xanthate adsorbed on CuO nanoparticle surfaces. A red-shift phenomenon, i.e., the absorption peak at 1200 cm^-1 shifted to 1193 cm^-1, was observed in the FTIR spectra. However, there was no obvious change in the peak intensity after desorption using ultrapure deionized water, indicating that butyl xanthate was chemisorbed on the CuO surface. We determined the order of the spectral intensity changes in the adsorption process using twodimensional (2D) IR spectroscopy. The 2D asynchronous spectra showed that the spectral intensity of the characteristic peak at 1265 cm^-1 changed first. This may be attributable to the combined peaks of dixanthogen and xanthate molecular aggregates at the surfaces. The adsorption kinetics was studied by monitoring the intensity changes of the xanthate characteristic peak at 1200 cm^-1. The adsorption kinetic data showed that the maximum chemisorption capacity of CuO for butyl xanthate was 529 mg·g^-1, and the adsorption kinetics can be described by a pseudo-second-order reaction model.