纳米SnO_2/TiO_2电极的制备及其电催化降解间-硝基苯酚

Preparation of Nano-crystalline SnO_2/TiO_2 Electrode and Its Electro-catalytic Degradation Toward m-Nitrophenol

用电化学方法在乙二醇溶液中制备锡、钛醇盐配合物Sn0.75Ti(OCH2CH2OH)(7-x),将电解液水解、干燥后在400℃煅烧2 h,得到纳米级SnO2/TiO2粉体。通过红外光谱(FT-IR)和拉曼光谱(Raman)对电解产物进行测试,纳米SnO2/TiO2粉体通过X射线粉末衍射(XRD)和扫描电子显微镜(SEM)进行表征。实验表明,在有机体系电解得到的纳米SnO2/TiO2粉体颗粒分散较理想,粒径在100～200 nm。再通过溶胶-凝胶法在钛丝表面得到纳米SnO2/TiO2电极,采用循环伏安法研究电极在酸性溶液和间-硝基苯酚溶液中的氧化还原行为和电催化活性。结果表明,纳米TiO2掺杂SnO2电极的氧化峰电流达到143×10-3A/cm2,氧化还原峰电位差明显减小,催化降解间-硝基苯酚的COD去除率达到86.1%,具有较高的电催化活性。

The precursor Sn0.75 Ti （OCH2 CH2 OH）（7-x） was synthesized by electrolysis of titanium and tin in glycol solution. Nano-crystalline SnO2/TiO2 powder was prepared by direct hydrolysis from the precursor and then calcined for ：2 h at 400 ℃. The metal alkoxide was characterized by FT-IR and Raman spectra. The mono-dispersed structure and the diameter of nano-SnOJTiO2 were observed by XRD and SEM. The results showed that SnO2/TiO2 of 100 - 200 nm was obtained in organic solution. The highly active nano-SnO2/TiO2 electrode was prepared using electro-synthesis and sol-gel method. The cyclic voltammetry was used to study the redox behavior and electro-catalytic activity of the nano-SnO2/TiO2 electrode in HCI/m-NOEC6H4OH solution. The current density of the electrode increased obviously and reached to 143×10^-3A/cm^2. The electrode potential difference of the redox peaks decreased obviously. The COD removal rate of m-nitrophenol reached to 86. 1% and the SnO2/TiO2 electrode had high electro-catalytic activities.