Preparation method of noble metal sensitized nano-porous SnO2-based gas sensitive material

Abstract

The invention provides a preparation method of a noble metal sensitized nano porous SnO2-based gas sensitive material, and belongs to the field of advanced porous nano materials. According to the preparation method, dihydric alcohol is used as a solvent and a metal precursor modifier, and an amphiphilic block copolymer is used as a structure inducer; when the SnO2 precursor and the noble metal precursor are co-assembled by the structure inducer, the dihydric alcohol and the SnO2 precursor are firstly chelated to form a metal chelate, and then the metal chelate and the amphiphilic block copolymer form a reversed-phase composite micelle; when solvent evaporation is carried out after assembly is completed, the reversed-phase composite micelles are further stacked to form a super-molecular assembly, a framework is provided for calcination, and a large-aperture mesoporous channel is formed after the structure inducer is decomposed through calcination, so that the noble metal sensitized nano-porous SnO2-based gas-sensitive material is obtained. The synthesis method disclosed by the invention is low in requirements on synthesis conditions, high in reaction yield and easy for industrial production, and can be applied to development and application of various high-performance gas sensors.

Description

technical field [0001] The invention belongs to the field of advanced porous nanomaterials, in particular to a noble metal sensitized nanoporous SnO 2 Preparation method of base gas-sensing material. Background technique [0002] As a typical n-type semiconductor, tin oxide is a commonly used metal oxide semiconductor gas sensing material with high electron mobility, wide band gap, non-stoichiometry, good thermal stability and other properties. However, single-component SnO 2 When semiconductor gas sensing materials are used for gas sensing, there are problems such as slow response, long recovery time and poor stability. [0003] In the prior art, improving SnO 2 The gas-sensing performance strategy of semiconductor materials includes three directions: one is to modify its components, such as noble metal modification, for example, the Chinese patent publication number CN112225255A discloses an ordered double mesoporous metal oxide loaded with noble metals. Composite mate...

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Problems solved by technology

[0004] Although it has been reported that nanoporous SnO 2 synthesis, but due to the common SnO 2 Precursors such as SnCl 4 , SnCl 2 The hydrolytic polymerization rate of the mesoporous SnO is relatively fast, and it is usually necessary to use a large amount of organic solvents and acid-base catalysts to regulate the hydrolytic polymerization process of the metal oxide precursor, and strictly control the synthesis conditions such as ambient humidity, reaction temperature, and hydrolysis time, resulting in mesoporous SnO 2 The high synthesis cost and low output greatly limit its industrial application; in addition, the traditional nanoporous SnO 2 During the synthesis process, when the template agent is removed by calcination at high temperature, the material framework is prone to shrinkage and reorganization, which leads to the collapse of the entire mesoporous framework. Therefore, the synthesis of large-pore nanoporous tin oxide is still facing great challenges.