纳米TiO_2-Pt修饰电极上甲醇的电催化氧化研究

用电化学法合成前驱体Ti(OEt)4,经直接水解法制备纳米TiO2膜,通过直接在纳米TiO2膜上电沉积Pt微粒得到纳米TiO2 Pt复合催化电极。扫描电子显微镜(SEM)和X射线衍射(XRD)分析结果表明,纳米TiO2的晶形为锐钛矿型,粒径约30nm,电沉积纳米Pt粒子(平均粒径约60nm)均匀地分散在纳米TiO2膜表面。循环伏安和计时电位测试表明,纳米TiO2 Pt修饰电极对甲醇的电氧化具有高催化活性和稳定性,Pt载量为0 68mg/cm2时,室温下甲醇氧化电流达到190mA/cm2,是纯Pt电极上的7 6倍。

Investigation on Electrocatalytic Oxidation of Methanol on Nanocrystalline TiO2-Pt Modified Electrode

The precursor Ti(OEt)_4 prepared by anodic dissolution of metallic titanium in absolute ethanol was directly hydrolyzed to give nano-TiO_2 film on titanium electrode (Ti/nano-TiO_2) by a sol-gel process.The nano-TiO_2-Pt composite catalytic electrode was achieved by direct electrodeposition of Pt nanopaticles onto nano-TiO_2 film.The nano-TiO_2 film and nano-TiO_2-Pt electrode were characterized by XRD and SEM,showing that the nano-TiO_2 (anatase) particle size is about 30 nm and Pt nanoparticles (60 nm) disperse uniformly on nano-TiO_2 film.The electrocatalytic activity of the nano-TiO_2-Pt electrode was investigated by cyclic voltammetry and chronopotentiogram.The results indicate that the nano-TiO_2-Pt electrode exhibits very high electrocatalytic activity and stability for the oxidation of methanol at room temperature.When Pt loading was 0.68 mg/cm~2,the oxidation current of methanol was 190 mA/cm~2,7.6 times that on pure Pt electrode.