摘要
可见光照射下(λ>420 nm)采用天然赤铁矿为催化剂降解罗丹明B(rhodamine B,RhB)和无色小分子2,4-二氯苯酚(2,4-dichlorophenol,DCP),探讨了溶液pH、催化剂用量、溶液中溶铁量对降解反应的影响,通过紫外-可见分光光度计、红外光谱仪、苯甲酸荧光光度法以及COD等跟踪降解过程,并对反应机制做了初步探讨.结果表明,Cata/RhB/H2O2/vis体系能有效地降解RhB,降解最佳条件为:催化剂用量0.6 g.L-1、pH为3.0、H2O2浓度1.5×10-3mol.L-1,反应180 min可完全脱色,且溶铁对催化体系的贡献较小;对2,4-DCP的降解,24 h后,降解率达56%.且该催化剂具有良好的稳定性,循环使用6次,催化剂活性无明显变化.苯甲酸荧光光度法检测到反应体系中产生了高活性氧化物种.OH,反应机制主要是.OH的异相类Fenton过程.
Hematite was used as the catalyst to degrade the rhodamine B and 2,4-dichlorophenol under visible light irradiation.The effect of pH,catalyst dosage and dissolved iron on the degradation efficiency were studied.UV-Vis spectrophotometer,infrared spectrometer,fluorescence spectrophotometry and the chemical oxygen demand（COD） were employed to evaluate the mechanism during the degradation process.The result indicated that RhB could be degraded effectively by the Cata/RhB/H2 O2/vis system.The optimum conditions were 0.6 g·L-1 catalyst;pH 3.0 and 1.5×10-3 mol·L-1 H2 O2.RhB was decomposed after 180 min and 56% of 2,4-DCP was degraded after 24 h by this syetem.Dissolved Fe ion was a relatively weak factor for the catalyst system.The catalyst had excellent stability with little loss of activity after 6 recycling experiments.The degradation process was dominated by the hydroxyl radical（·OH） generated in the heterogeneous Fenton-like system.
出处
《环境科学》
EI
CAS
CSCD
北大核心
2012年第4期1247-1251,共5页
Environmental Science
基金
国家自然科学基金项目(20877048
21177072)
中南民族大学催化材料重点实验室开放课题项目(CHCL10007)
湖北省自然科学基金创新群体项目(2009CDA020)
湖北省环境保护专项(2008HB08)
关键词
赤铁矿
光催化
异相类Fenton
羟基自由基
矿化
hematite
photo-catalytic
heterogeneous Fenton-like
hydroxyl radical
mineralization
