MIL-101(Cr^(3+))可见光催化氧化降解甲基橙的研究

Visible-Light Photocatalytic Degradation of Methyl Orange with MIL-101(Cr^(3+))

以金属有机多孔材料MIL-101(Cr3+)为非均相催化剂,过硫酸钠(Na2S2O8)为类Fenton体系的氧化剂,在可见光(300 W)下对甲基橙进行催化氧化降解研究。结果表明,MIL-101(Cr3+)在反应时间为120 min时对甲基橙降解率高达91.0%,且回收利用3次后仍表现出优异的降解性能(降解率达到81.0%)。同样条件下,把MIL-101(Cr3+)替换为TiO2或者不添加任何催化剂,甲基橙的降解率分别为25.6%和8.8%。采用紫外-可见漫反射光谱考察了常温下MIL-101(Cr3+)的禁带宽度大小,进一步证明其优异的光催化降解性能;同时还探讨了MIL-101(Cr3+)催化降解甲基橙的可能机理。

The degradation of methyl orange with MIL-101（Cr^3＋） as heterogendous photocatalyst and Na2S2O8 as oxidant of Fenton system was carried out under 300 W daylight lamp. Results revealed that the degradation efficiency MIL-101（Cr^3＋） can reach to 91% at the reaction time of 120 min. Moreover, the catalyst could be reused at least three times without loss of any activity, with degradation efficiency up to 81%. At the same conditions, the photodegradation activity results of MIL-101（Cr^3＋）were compared with the activity of P25（TiO2） and a control blank（i.e. non-catalytic）. The results showed that the control experiments with or without P25 were 25.6% and 8.8% respectively. Moreover, the band gap size of MIL-101（Cr^3＋） was investigated by UV-vis diffuse reflection measurement method at room temperature, which indicated that MIL-101（Cr^3＋） is an excellent candidate for photocatalyst. The photocatalytic mechanism of MIL-101（Cr^3＋） was also investigated.