Preparation Of Compound Nano TiO₂/SiO₂: By Sol-gol Method And Study On Adsorption Behaviors Of Heavy Metalions

SPE, a sample pretreatment technology, has developed in recent years, it has more usedin extraction, enrichment and purification of semi volatile and nonvolatile organic compoundsin sample. The technology used to analysis heavy metal in water has been attended byanalysis test workers. Nanomaterials as SPE adsorption materials have showed considerableprospect in separation and enrichment of trace metal elements. In this paper, hydrolysis ofbutyl titanate, ethyl silicate as precursor, ethanol, acetic acid and deionized water as rawmaterials by sol gel method process TiO₂/SiO₂composites materials. Synthesis conditions ofnanometer TiO₂/SiO₂was explored by experiment, the former reaction experiment to rawmaterial ratio was ethyl silicate: no water ethanol: deionized water=1:2:2; butyl titanate:ethanol: acetic acid: deionized water=1:4:2:0.3, roasting temperature was600℃, roastingtime was4h. Crystal structure, particle size, crystal morphology of the synthesized materialswas characterized by X-ray diffraction and transmission electron microscopy. XRD analysisshowed that nano-particles in TiO₂/SiO₂calcination temperature of1000℃also does notappear rutile. TEM images show, TiO₂/SiO₂basic spherical shape of nano-particles, particlesize10-20nm. Representating its crystalline nature, particle size and particle shape with XRDand TEM. XRD analysis showed that nano-particles TiO₂/SiO₂did not appeared tutile TiO₂when temperature get1000℃. The TEM showed that TiO₂/SiO₂as aphere and its particle sizebetween10-20nm. It is a examination of adsorption performance of nanometer TiO₂/SiO₂with different pH to Cu²⁺、Cr³⁺、Pb²⁺and Hg²⁺and using Composite nano TiO₂/SiO₂as solidphase extraction packing, ICP-MS as testing method. The results show that adsorption ratewas reach maximum with the pH increased. Get the minimum detection limit of Cu²⁺、Cr³⁺、Pb²⁺and Hg²⁺was0.31μg/L、0.25μg/L、0.10μg/L and0.41μg/L respectively.