物理化学学报 >> 2008, Vol. 24 >> Issue (08): 1524-1528.doi: 10.3866/PKU.WHXB20080834

研究简报 上一篇    下一篇

脉冲流光放电激发解离H2O分子的动力学过程

张连水; 王百荣; 党伟; 肖广长生   

  1. 河北大学物理科学与技术学院, 河北 保定 071002
  • 收稿日期:2008-01-18 修回日期:2008-04-15 发布日期:2008-08-06
  • 通讯作者: 张连水 E-mail:zhangls@hbu.edu.cn

Excited Dissociation Kinetics of H2O by Pulsed Streamer Discharge

ZHANG Lian-Shui; WANG Bai-Rong; DANG Wei; XIAO Guang-Chang-Sheng   

  1. College of Physics Science and Technology, Hebei University, Baoding 071002, Hebei Province, P. R. China
  • Received:2008-01-18 Revised:2008-04-15 Published:2008-08-06
  • Contact: ZHANG Lian-Shui E-mail:zhangls@hbu.edu.cn

摘要: 采用色散荧光光谱、时间分辨光谱和空间分辨光谱方法, 在标准大气压(1.013×105 Pa)下, 对以N2气为载气的H2O蒸气脉冲流光放电等离子体激发解离反应动力学过程进行了实验研究. 将所得色散荧光谱归属于N2(C3∏u→B3∏g)、·OH(A2∑+→X2∏)、H(n=3→n=2)的辐射跃迁; 并对N2*、·OH*、H*三种活性粒子的指纹灵敏谱线(337.2、308.4、656.5 nm)荧光信号进行了时间分辨测量. 结果表明,·OH*和H*荧光信号分别滞后N2*荧光信号7.4 ns 和17.6 ns, 由此推断H2O分子的激发解离通道为: H2O分子与高能电子发生非弹性碰撞激发, 被激发到第一激发电子态的高振动能级, 然后自解离成激发态的·OH*自由基和基态的H原子. 空间分辨测量结果表明, 在距负电极0.5 mm附近, 活性荧光粒子浓度最高, 正好对应流光放电的负辉区, 该区域电子温度和电子浓度最高, 更有利于活性粒子的产生.

关键词: 脉冲流光放电, 激发解离动力学过程, 色散荧光谱, 时间分辨光谱, 空间分辨光谱

Abstract: The methods of the disperse fluorescence, temporal-resolved spectrum and spatial-resolved spectrum were used to study the excited dissociation kinetics of N2/H2O gas in the pulsed streamer discharge plasma at the standared atmospheric pressure (1.013×105 Pa). The main spectra detected in the experiment are assigned to C3∏u→B3∏g for N2, A2∑+→X2∏ for·OH radical, and (n=3→n=2) for H atom, respectively. The temporal-resolved measurements at 337.2, 308.4, 656.5 nm showed that the occurrences of·OH* and H* were 7.4 ns and 17.6 ns later than that of N2* respectively. So the dissociation process of H2O can be described as that H2O is excited to high vibrational level of the first excited state by non-elasticity collision with electron, and then dissociates to·OH* radical at excited state and H atom at ground state. Furthermore, spatial-resolved measurements showed that the densities of active particles reached the maximum at 0.5 mm away from negative electrode corresponding to the negative glow region of streamer discharge, where the maxima of electron temperature and density were helpful to the formation of these active particles.

Key words: Pulse streamer discharge, Excited dissociation kinetics process, Disperse fluorescence spectrum, Temporal-resolved spectrum, Spatial-resolved spectrum

MSC2000: 

  • O646