The Synthesis And Gas Sensing Property Of Mesoporous Transition Metal Oxide Nanoparticles

Transition metal oxides have great practical value in terms of catalysis,biomedical, and environmental protection for their nice properties. Whenimproved from block to mesoporous nano materials, they get the doubleadvantages of nano and mesoporous, the reaction active sites increasing, andthe performance improving with the specific greatly increasing of the surfacearea, reaction active sites, and performance.Our study focused on the synthesis of Fe2O3through hard template methodand the various factors which might affect the reaction system. The impact ofthe structure of materials for gas sensing properties was also concerned. Theresults were showed below:1, On the basis of the previous synthesis of block mesoporous transitionmetal oxides, we re-explored the synthesis conditions, summed up thesynthesis method for mesoporous nanoparticles. Three kinds ofmesoporous Fe2O3nanoparticles were produced by choosing differentsolvents, different template surface conditions and different templatestructures. At the same time, the impacts of various factors in the reactionsystem were tested, and reasonable explanations were given. 2, By testing the gas sensing property to ethanol of this novel structuralmaterials, we found that the sensing property of this material was muchhigher than the bulk material where the environment of the ethanolconcentration of1000ppm, for example, if bulk materials, almostnon-sensitive could be found. when be made into mesoporous materials,the reported sensitivity approximately6-8, the mesoporous nanoparticlesmaterials we prepared had a sensitivity of16-20, which had beensignificantly improved; In addition, Gas sensing property of optimization isalso reflected in the reduction of response time. When this materialcontacted the ethanol environment, signal changed occurred in just a fewseconds, which greatly expanded its application. The reasons for thissituation are ferric oxide, especially of α-Fe₂O₃is a surface-controlled gassensing materials occurring on the surface of the contact surface with theethanol-sensitive, so raising the surface area will greatly enhance the gassensing nature.3, We also try to use the experience obtained in the synthesis of Fe₂O₃tothe synthesis of other mesoporous transition metal oxides nanoparticles,just like Co3O4, In₂O₃, CeO2. Each precursor has its own different properties,and the binding capacity of the hole wall, the deposition rate is also different.Therefore, in the case of other conditions same, the resulting products ofmorphology, size, dispersion, are not the same.