Formation of radical intermediates upon photocatalytic (UVA) glycerol transformation in aerated aqueous TiO₂ (P25) suspensions was followed by EPR spin trapping technique. Character and concentration of the spin-adducts generated by the addition of the radical species to 5,5-dimethyl-1-pyrroline N-oxide (DMPO) spin trap are significantly affected by the UVA radiation dose and by the initial composition of the photocatalytic system. The DMPO spin-adducts of hydroxyalkyl radicals R1 and R2 detected in the aerated aqueous P25 suspensions containing glycerol are compatible with the H-abstraction processes attributed to the interaction of physisorbed glycerol molecules with the trapped holes or to the reaction of free hydroxyl radicals with glycerol in solution. Addition of fluoride at various concentrations has no effect on the character and concentration of DMPO spin-adducts observed upon in situ UVA photoexcitation of photocatalytic system P25/DMPO/glycerol under given experimental conditions (pH > 7).

在充气的TiO ₂（P25）水性悬浮液中通过光催化（UVA）甘油转化形成自由基中间体，然后采用EPR自旋捕集技术。通过将自由基物质添加到5,5-二甲基-1-吡咯啉N-氧化物（DMPO）自旋阱中而生成的自旋加合物的特性和浓度受UVA辐射剂量和光催化的初始组成的影响很大系统。羟烷基基团R1和DMPO的自旋加合物在含甘油的充气P25水性悬浮液中检测到的R2与H吸收过程兼容，这归因于物理吸附的甘油分子与陷留孔的相互作用或溶液中游离羟基与甘油的反应。在给定的实验条件下（pH> 7），以不同浓度的氟化物添加对光催化体系P25 / DMPO /甘油的原位UVA光激发后观察到的DMPO旋加合物的特性和浓度没有影响。