Synthesis Of Rh@In₂O₃ With Ordered Mesoporous Structure And Their Sensing Properties

Indium oxide is an n-type semiconductor.It is rich in non-quantitative chemical defects,has unique conductivity,good stability,and a suitable band gap(3.7～3.75 eV).It is an ideal carrier for gas-sensitive materials.We judge the quality of the gas-sensitive material carrier.There are usually two criteria-the specific surface area is large,which is conducive to the diffusion of gas and can provide a large number of catalytic reaction sites;the electron transmission channel is well-connected,which can improve its sensitivity to lower its detection limit.Alcohols(typically represented by ethanol)are a common class of volatile organic compounds,often used as organic solvents,extractants,antifreeze,etc.In this paper,ethanol and its homologues are selected as the target gas.1.Using SBA-15 as a template,indium oxide nanomaterials with ordered mesoporous structure were prepared.The precious metal on the carrier is used to enhance the ethanol-sensing performance of the ordered mesoporous In2O3.Homogeneous reduction was used to synthesis Rh@In2O3 ordered mesoporous materials,which significantly improves the response value of the gas-sensitive material to ethanol gas(from 31 to 201).When the load is 1%,the response value is the highest and has a decreasing detection limit.2.On the basis of the above research,optimize the synthesis conditions of the hard template method to improve its performance,and then use n-pentanol as the solvent for heterogeneous reduction to obtain a gas-sensitive material with higher sensitivity(response of 1193 for 100 ppm).The response value is highest when the load is 0.5%.Using this material as a detection probe,the gas-sensing properties of C1～C4 short-chain fatty alcohols are tested to explore the influence of gas structure on gas-sensing properties.