摘要
利用紫外及红外吸收光谱等分析手段对365 nm光照下HNO3在气相与SiO2表面的光解反应进行了研究.考察了HNO3浓度、光照时间、相对湿度等条件对反应的影响.结果表明:随着HNO3浓度及光照时间的增加,光解产生的NO2和NO浓度均呈指数增加;无水汽情况下,400 Pa的HNO3光解45 min后,产生NO2及NO浓度比气相光解产生的分别高约3及1.7倍.HNO3光解产生的HONO的浓度随相对湿度的增加而呈线性增加,在SiO2颗粒物表面光解产生的NO2浓度随着相对湿度的增加而减少,而NO浓度则随之增大.400 Pa的HNO3光照45 min后,SiO2表面光解产生的HONO浓度是气相光解的3倍、SiO2表面暗反应的约30倍.
UV photolysis of nitric acid in the gas phase and on the SiO2 surface at 365 nm was studied by using UV-vis absorption and Fourier transform infrared spectroscopy （ FT-IR） . The effects of HNO3 initial concentration, relative humidity and irradiation time were investigated. Results showed that photolysis of HNO3 produced NO2 and NO in the gas phase and on the SiO2 surface. With the increase of HNO3 initial concentration and irradiation time, both NO2 and NO concentrations. When HNO3 initial concentration was 400 Pa, irradiation time was 40 min and in the absence of water vapor, NO2 and NO concentration from photolysis of HNO3 on SiO2 was about 3 and 1.7 times higher than these without SiO2, respectively. With the increase of relative humidity, HONO concentration increased linearly, and the concentration of NO2 and NO from gas phase reaction remained constant, while the concentration of NO2 from SiO2 reaction decreased and NO increased. When HNO3 initial concentration was 400 Pa and irradiation time was 40 min, HONO concentration from photolysis of HNO3 on SiO2 surface was about 3 and 40 times higher than its gas phase and dark reaction, respectively.
出处
《环境化学》
CAS
CSCD
北大核心
2015年第4期748-753,共6页
Environmental Chemistry
基金
国家自然科学基金项目(21177034)资助
