基于脉冲放电等离子体/TiO2的协同作用效果,研究利用脉冲放电过程中产生的紫外光效应,建立以玻璃珠负载的TiO2膜作为光催化剂的脉冲放电等离子体/TiO2协同体系,并从氧自由基(·O)光谱分析的角度说明脉冲放电等离子体/TiO2光催化的协同作用机理.研究结果表明,·O主要在777 um处形成特征发射光谱,对应跃迁为3p5P→3s5S;分别以空气和氧气为载气时,脉冲放电等离子体/TiO2协同体系中·O的相对发射光谱强度均高于单独脉冲放电体系中的相对强度,证明水溶液中脉冲放电过程形成的紫外光可以诱导体系中负载型TiO2的光催化活性;在单独脉冲放电体系和协同体系中,苯酚溶液中·O的相对发射光谱的强度均低于相同条件下纯水溶液中的相对强度,说明·O是促使苯酚降解的氧化性自由基.%Based on the synergistic effect of pulsed discharge plasma and titanium dioxide (TiO2) photocatalysis, a coupling system of pulsed discharge plasma/TiO2 was set up in the present paper, by using the ultraviolet radiation produced during the pulsed discharge process. TiO2 film immobilized on the glass beads was used as the photocatalyst in the synergistic system. In the research, the synergistic mechanism of pulsed discharge plasma and TiO2 photocatalysis was reviewed by the spectral diagnosis of oxygen radical (·O radical) produced in different reaction systems. The obtained results showed that the characteristic emission spectrum of · O radical could be observed at 777 nm and the corresponding transitions was 3p5P→3s5S. When air was used as bubbling gas, the relative emission intensity of · O radical recorded in the synergistic system was stronger than that in the plasma alone system, and the same result was also obtained when oxygen (O2) was used as bubbling gas. This result revealed that the photocatalytic activity of the immobilized TiO2 in the synergistic system could be induced by the ultraviolet radiation formed during the pulsed discharge process. In the systems of pulsed discharge plasma alone and pulsed discharge plasma combined with TiO2 photocatalysis, the relative emission intensity of · O radical in distilled water was stronger than that in phenol solutions. The results showed that · O radical was one of responsible radicals for phenol degradation in the pulsed discharge plasma alone system as well as the synergistic system.
展开▼
