Methanol Adsorption on TiO2 Film Studied by Sum Frequency Generation Vibrational Spectroscopy  

二氧化钛薄膜表面甲醇吸附的和频振动光谱

作　　者：冯冉冉[1,2] 刘安安[1] 刘烁[1] 施骄健 刘怡[1] 任泽峰[1] 

机构地区：[1]北京大学物理学院量子材料科学中心,北京100871 [2]量子物质科学协同创新中心,北京100871

出　　处：《Chinese Journal of Chemical Physics》2015年第1期11-16,I0001,共7页化学物理学报（英文）

基　　金：This work was supported by the National Ba- sic Research Program of China （No.2013CB834600） and the National Natural Science Foundation of China （No.II27002/B030403, No.II290162/A040106, and No.21322310/B030402）.

摘　　要：A broadband infrared surface sum frequency generation vibrational spectroscopy （SFG-VS） and an in situ UV excitation setup devoted to studying surface photocatalysis have been constructed. With a home-made compact high vacuum cell, organic contaminants on TiO2 thin film surface prepared by RF magnetron sputtering were in situ removed under 266 nm irradiation in 10 kPa 02 atmosphere. We obtained the methanol spectrum in the CH3 stretching vibration region on TiO2 surface with changing the methanol pressure at room temperature. Features of both molecular and dissociative methanol, methoxy, adsorbed on this surface were resolved. The CH3 symmetric stretching vibration frequency and Fermi resonance of molecular methanol is red-shifted by about 6-8 cm-1 from low to high coverage. Moreover, the recombination of dissociative methanol and H on Surfaces in vacuum was also observed. Our results suggest two equilibria exist： between molecular methanol in the gas phase and that on surfaces, and between molecular methanol and dissociative methanol on surfaces.

关 键 词：Surface sum frequency generation vibrational spectroscopy Surface photo-catalysis TIO2 

分 类 号：O433[机械工程—光学工程] O643.36[理学—光学]