摘要
选取6种天然铁锰矿石为光催化剂,以可见光(λ>420nm)照射下活化H2O2降解有机染料罗丹明B(RhodamineB,RhB)为探针反应,筛选出活性较高的天然矿石(磁赤铁矿)催化降解RhB及2,4-二氯苯酚(2,4-Dichlorophenol,DCP).实验表明,可见光下磁赤铁矿在pH=7.0的介质体系,H2O2浓度为3×10-3mol·l-1条件下可有效降解RhB.通过反射紫外光谱、原子吸收分光光度法、XRD初步表征了磁赤铁矿组成结构;采用紫外-可见吸收光谱(UV-vis)、红外光谱(IR)、总有机碳(TOC)测定等方法,研究了其可见光照射下对RhB光催化降解特性.结果表明,在实验条件下RhB矿化率达60%,DCP矿化率达到63.93%.利用电子自旋捕捉技术(ESR)跟踪测定RhB降解过程中氧化物种,表明催化降解过程涉及羟基自由基(·OH)氧化过程.拟定异相矿石类Fenton体系与传统均相Fenton体系相比,具有反应介质pH范围宽(3.0—7.0)、可见光激发及催化剂易得廉价等优势。
Six kinds of natural mineral were selected to degrade on organic dye Rhodamine B（RhB） under the visible light.Natural ore（maghemite） with high activity to degrade RhB and small molecular compound 2,4-dichiorophenol（DCP） was selected by comparing the catalytic activity of all the minerals.The results showed that the maghemite had the highest catalytic activity at pH 7.0,H2O2 concentration 3 × 10-3mol·l-1 and catalyst dosage 30mg under visible light irradiation.Maghemite＇ s composition and structure were characterized by UV-vis reflection absorption spectrometry,atomic absorption spectrometry and XRD.The degradation process of RhB was studied by UV-visible spectrometry（UV-vis）,IR and total organic carbon（TOC）.The results indicated that RhB and DCP were degraded effectively with a mineralization ratio of 60.00% for RhB and 63.93% for DCP.Electron spin resonance（ESR） spin-trapping technique determination showed the process of this reaction followed the mechanism of hydroxyl radical oxidation.Compared with traditional Fenton system,heterogeneous Fenton-like system has a wider applicable pH range（3.0—7.0）,can make full use of visible light,and is easy to get.
出处
《环境化学》
CAS
CSCD
北大核心
2010年第6期1032-1037,共6页
Environmental Chemistry
基金
国家自然科学基金(20877048)
国家重点基础研究发展计划(973)项目前期预研课题(2008CB417206)
湖北省高校优秀中青年创新团队计划(T200703)
湖北省自然科学基金创新群体项目(2009CDA020)资助
