The Synthesis Of Nano Titanium Dioxide And Ruthenium-Titanium Composite Oxide From Tin Via Impregnation-thermal Decomposition Method

In this paper, nano-powder of rutile TiO2and ruthenium-titanium compositeoxides with different Ru mole ratios (Ti1-xRuxO2, x=0.1,0.2,0.3,0.4,0.5,0.6,0.7)were synthesized from TiN nanoparticle precursors via impregnation-thermaldecomposition method. The structure, composition, morphology, electrocatalysisactivity and stability of as-synthesized samples were characterized by X-raydiffraction (XRD), energy dispersive spectrometer (EDS), transmission electronmicroscopy (TEM)， Brunauer-Emmett-Teller (BET)，polarization curve and cyclicvoltammetry (CV). The gas-solid phase reactions of TiN nanopowder both withoutand with impregnation pretreatment and the formation process of Ti1-xRuxO2solidsolution were studied by thermogravimetric-differential scanning calorimetry analysis(TG-DSC). It is significant and worthy to SPE (Solid Polymer Electrolytes)membrane electrode technology and developing new type of fuel cell electrolysissystem. The main conclusions were as follows:Preparation of rutile TiO2by TiN impregnation-thermal decomposition method:(1)The XRD、 TEM、 BET results showed that TiN nanopowder withoutimpregnation were oxidized into anatase TiO2at350～550℃, whereas rutile TiO2were obtained from TiN nanopowder impregnated with mixed solution of n-butanoland hydrochloric acid in air at380℃. Well dispersed rod-like rutile TiO2of16nm wasobtained with the1:7volume ratio of hydrochloric acid to n-butanol in impregnatingsolution. It shows that hydrochloric acid acts as the fundamental substance for rutileTiO2from TiN nanopowder at low-temperature, while n-butanol mainly inhibits theagglomeration of TiO2.(2) TG-DSC analysis showed that TiN nanopowder with impregnation wereoxidized into rutile TiO2at373℃directly, not experiencing the anatase to rutile phase transformation in traditional thermal oxidation process.Preparation of Ti1-xRuxO2by TiN impregnation-thermal decomposition method:(1) XRD and TEM results showed that rutile Ti1-xRuxO2were nanorods in theform of solid solution and had better dispersion, with particle size distributing fromtens of nanometers to a few nanometers. Conductivity tests demonstrated thatTi1-xRuxO2nanopowder had low resistivity, that is to say, it had good electricalconductivity. EDS analysis showde that the composite oxide contained Cl atoms,which indicates that some Cl atoms replaced the location of oxygen atom, thusincreasing the oxygen deficiency of the crystal.(2) TG-DTG and TG-DSC curves showed TiN were completely oxidized intorutile TiO2after the first impregnation. Both RuCl3·3H2O oxidizing into rutile RuO2and RuO2solution into TiO2crystal lattice run through the whole process, and the twooccurred simultaneously.(3) The electrochemical tests of Ti0.7Ru0.3O2nanopowder exhibited it had highelectrocatalysis activity for chlorine evolution, while was poor for oxygen evolution.Cyclic voltammetry curves in0.1mol·L-1HCl solution indicated Ti0.7Ru0.3O2hadexcellent stability.