Fabrication of 3D ultrathin porous heterostructural Co3O4/Al2O3 material based on LDHs memory effect and its high NOx sensing performance at room temperature

To address the issues of high cost and low sensitivity of core materials in gas monitoring, 3D ultra -thin porous Co 3 O 4 /Al 2 O 3 sensing material with high sensitivity towards nitrogen oxide was prepared by a one-step hydrothermal method. SEM and TEM tests show that the obtained material well inherits the advantages of CoAl layered double hydroxide matrix based on memory effect. It forms an ultra -thin porous 3D flower-like structure with a pore size of 50 nm. The average thickness of the nanosheets is measured at 5.5 nm by AFM. The performance tests indicate that CA2 has a response value of 32.28 to NO x at a concentration of 100 ppm, with a detection limit as low as 50 ppb, and the stability is up to 50 days. As XPS and EPR analyses indicated, the material prepared by our method will separate oxygen in the lattice and form oxygen defects under high temperature conditions. The combined effect of chemically adsorbed oxygen and oxygen defects promotes the effective adsorption of nitrogen oxides. Meanwhile, the large specific surface area (88.65 m 2 & sdot;g - 1 ) improve the efficiency of electron transfer from the material to NO x , ultimately enhancing the detection sensitivity of NO x .