新型Ti/TiO_2电极的制备及其光电催化氧化活性

采用电解氧化金属钛网的方法制备新型光电极Ti/TiO2 ,采用X射线衍射仪、激光拉曼光谱仪与扫描电镜测试电极的表面晶体结构与表面形态。以腐殖酸溶液的总有机炭 (TOC)的变化来评价电极的光电催化氧化活性。结果表明 ,电解电压与电流密度对电极表面的晶体组成、表面形态、孔隙大小与中心电子的结合能影响较大。电极制备的最佳电解电压与电流密度分别为 16 0V ,110 0A/m2 。光电催化氧化可为给水处理提供一种方便、高效的方法。     

Photoelectrocatalytic properties and reactivity of Ti/Au-TiO2 mesh electrodes

A kind of photoelectrode was innovated by anodising titanium mesh in H2SO4 solution and photo-reduced in HAuCl4 solution and named Ti/Au-TiO2 mesh electrode.The structural and surface morphology of the Ti/Au-TiO2 mesh was examined by X-ray diffraction,laser Raman spectra,scanning electronic microscopy(SEM) and X-ray photoelectron spectroscopy respectively.The results indicate that its crystal structure,morphology and the size of pore are affected greatly by gold deposition.XPS measurement show that the valence band of Ti/TiO2 has two peaks:a wide one at 4.97eV and a narrow one at 6.61eV,which correspond mainly to π(nonbonding)and σ(bonding)O 2p orbitals,The emission intensity of O 2p orbitals becomes stronger and the width of the valence band increases with the increase of Au content.And the emission of nonbonding shifts toward lower binding energy and that of bonding O 2p orbitals shifts toward higher binding energy.The photoelectrocatalytic(PEC) oxidation of humic acid( HA) was investigated in terms of TOC.The PEC oxidation efficiency of Ti/Au-TiO2 mesh with optimal content of gold is higher than that of Ti/TiO2 mesh.It is suggested that the recombination of electrons and holes is hindered owing to gold deposition.The investigation shows that PEC oxidation is a convenient way to mineralize organic matter for water treatment.