Horikoshi Satoshi, Hojo Fukuyo, Hidaka Hisao, Serpone Nick
Frontier Research Center for the Global Environment Science, Meisei University, 2-1-1 Hodokubo, Hino, Tokyo 191-8506, Japan.
Environ Sci Technol. 2004 Apr 1;38(7):2198-208. doi: 10.1021/es034823a.
Thermal and nonthermal effects originating when a system is subjected to a microwave radiation field in the TiO2-photocatalyzed transformation of model substances containing various functional groups (e.g., benzoic acid, phthalic acid, o-formylbenzoic acid, phthalaldehyde, succinic acid, dimethyl phthalate, diethyl phthalate, and phenol) have been examined under simultaneous irradiation by ultraviolet (UV) and microwave (MW) radiations. Characteristics of the microwave effects and the fate of each substrate during the microwave-assisted photocatalytic process were monitored by UV absorption spectroscopy, HPLC methods, total organic carbon assays, and identification of intermediates using electrospray mass spectral techniques. Microwave thermal and nonthermal effects were delineated by comparing results from MW-generated internal heat versus conventional external heating, and at constant ambient temperature under a microwave field. Factors involved in the nonthermal component of the microwave radiation were inferred for the initial adsorption of the substrate and its subsequent degradation occurring on the surface of TiO2 particles. Microwave effects bear on the mechanism through which a model substrate undergoes oxidative degradation. A characteristic feature of these effects was briefly examined by considering the behavior of polar (dipole moments) substrates in a microwave radiation field.
在紫外（UV）和微波（MW）辐射同时照射下，研究了在TiO₂光催化转化含各种官能团的模型物质（如苯甲酸、邻苯二甲酸、邻甲酰基苯甲酸、邻苯二甲醛、琥珀酸、邻苯二甲酸二甲酯、邻苯二甲酸二乙酯和苯酚）时产生的热效应和非热效应。通过紫外吸收光谱、HPLC方法、总有机碳分析以及使用电喷雾质谱技术鉴定中间体，监测了微波辅助光催化过程中微波效应的特征和每种底物的去向。通过比较微波产生的内热与传统外部加热的结果，以及在微波场中恒定环境温度下的结果，来描述微波热效应和非热效应。推断了微波辐射非热成分中涉及的因素对底物在TiO₂颗粒表面的初始吸附及其随后降解的影响。微波效应影响模型底物发生氧化降解的机制。通过考虑极性（偶极矩）底物在微波辐射场中的行为，简要研究了这些效应的一个特征。
