石墨烯/TiO_(2)的氯化改性及其新式自由基反应

Chlorination Modification of Graphene/TiO_(2) and Its New Radical Reaction

成功制备了一系列石墨烯/TiO_(2)复合材料并分别氯化改性。以甲基橙和苯酚作为目标污染物,进行复合材料光催化降解活性实验;随后引入电化学和电子顺磁共振技术对该催化剂及其反应体系进行表征,推断其机理。结果表明,石墨烯具有极好的电子迁移能力,可以提高光生载流子的传递效率,进而增强TiO_(2)紫外催化性能。新型复合材料均表现出较高的光催化降解活性,甲基橙降解率由70%提升至100%,苯酚降解率由10%提升至100%。而表面氯化引入了新的活性基团,在光照条件下能够生成氯自由基,进而配合羟基、超氧,形成一种新的三自由基反应体系,使其氧化降解能力大幅提升。

The new graphene/TiO_(2) with different amount of graphene have been prepared and chlorinated respectively.Using methyl orange and phenol as target pollutants,the photocatalytic degradation activity experiment of composite materials was carried out.Then electro-chemistry and electron spin-resonance spectroscopy(ESR)technique were introduced to characterize the catalyst and its reaction system,and study its mechanism.The results showed that,graphene had excellent electron mobility,which could improve the transfer efficiency of photo-generated carriers,thereby enhancing the UV catalytic performance of TiO_(2).The new composite materials all showed high photocatalytic degradation activity,the degradation rate of methyl orange was increased from 70%to 100%,and the degradation rate of phenol was increased from 10%to 100%.The surface chlorination introduced new active groups,which could generate chlorine free radicals under light conditions,and then cooperated with hydroxyl and superoxide to form a new three-radical reaction system,which greatly enhanced its oxidative degradation ability.