新型仿生光催化剂HMS-FePcS催化孔雀绿在可见光下的降解历程

Photocatalytic Degradation Mechanism of Malachite Green under Visible Light Irradiation over Novel Biomimetic Photocatalyst HMS-FePcs

在可见光照射下,采用合成的新型仿生光催化剂HMS-FePcS催化降解孔雀绿模拟染料废水.由不同反应时间段反应液的HPLC谱和MS谱中产物峰的变化可知,孔雀绿的催化降解过程为先脱色后矿化.采用固体萃取法对孔雀绿降解的中间产物进行了富集和分离,并使用GC-MS对所得的中间产物进行了鉴定,确定出10余种中间产物.在此基础上对孔雀绿的降解历程进行了推测,指出孔雀绿的光催化降解主要从中心碳原子与二甲氨基苯基之间的C-C键处断裂,4-二甲氨基苯甲酮是此反应最常见的中间产物.当4-二甲氨基苯甲酮被羟基自由基进攻时,生成苯甲酸、对二甲氨基苯甲酸及对二甲氨基苯酚等化合物.这些小分子芳香类中间产物进一步发生羟基化反应,开环生成小分子脂肪酸类化合物.

Upon visible light irradiation in the presence of H2O2, the novel catalyst HMS-FePcS was found to be highly effective for the degradation of nonbiodegradable malachite green （MG）. High-performance liquid chromatography spectra and mass spectrometry spectra during the degradation process were analyzed to show that the MG degradation included its decolorization followed by the mineralization of intermediates. More than ten intermediates were confirmed through GC-MS, and the most probable degradation pathway for MG was proposed. The C-C bond between the central carbon atom and N, N-dimethylaminobenzyl was broken first to give the intermediate 4-（ N, N-dimethylamino） methylbenzylone. Subsequently, 4- （ N, N-dimethylamino） methylbenzylone reacted with strongly oxidative hydroxyl radicals. Finally, benzene rings were opened, and many small molecules such as fatty acids were produced.