A Study Of Mesoporous Metal Oxides’ Preparation And Applications By The Nitrates–Spray–Pyrolysis Method

Due to the nanostructured building blocks and abundant mass–transfer channels, the mesoporous materials have been widely used in the fields of catalysis, sensing, separation, adsorption, electrochemical devices, drug carrier/release and so forth. The aerosol–assisted self–assembly(AASA) route is an efficient way to continuously produce mesoporous microspheres. However, the metal oxides from AASA were limited as several kinds(For example, Al2O3, Ti O2 etc.) because the precursors were the metal–organic compounds, which are expensive, water–sensitive, and difficult to be prepared. This thesis builds a nitrate–spray–pyrolysis method(NSPM) system with metal nitrates as precursors for the versatile preparation of mesoporous metal oxides microspheres and their composites. The specific contents includes the following 3 parts.Firstly, this thesis confirmed the availability of NSPM to diverse mesoporous metal oxides with the evidence of the preparation of 13 kinds of monometallic metal oxides, and further discussed the effect factors on the morphology, microsphere size and pore structure. Besides, this thesis took the gas-sensing performance of α-Fe2O3 mesoporous microspheres as an example to suggest the applications of the mesoporous products from NSPM.Secondly, the thesis shown the advantages of NSPM in the design and fabrication of composite mesoporous metal oxides, such as Al–Zr–O amorphous mesoporous microspheres, Cu/Al2O3 hybrid mesoporous microspheres, metal ions–doped Zn O mesoporous microspheres and Au nanoparticles loaded mesoporous microspheres. In addition, this thesis took the photocatalytic oxygen evolution reaction of An/α-Fe2O3 mesoporous microspheres as an example to indicate the superior applications of the composite mesoporous products from NSPM.At last of this thesis, a highly active mesoporous electrocatalyst of La Mn O3+δ for oxygen reduction reaction(ORR) and Zn–air battery was presented from the identification of various mesoporous perovskites prepared by NSPM. The mass activity of mesoporous La Mn O3+δ catalysts is the highest among the reported La-based perovskite catalysts for ORR in alkaline media. As for the device study of Zn–air battery, the performance with La Mn O3+δ catalysts was highly close to that of with same–loaded commercial Pt/C catalyst.In a word, the results presented in this thesis is highly important to the study, production and potential applications of mesoporous metal oxides materials for the electrochemical devices, photocatalysis, sensing and so forth.