LAUSR

Abstract The fabrication of nano-structured 2D metal oxide materials using simple, low-cost, pollution-free and general method has been still challenging. Herein, mesoporous CeO2 nanosheets were prepared by simple cerium nitrate impregnation and calcination using tree leaves as template. Meanwhile, the influence of calcination temperature on microstructure and gas-sensing properties was also investigated. The CeO2-550 nanosheets calcinated at 550 °C are assembled by cross-linking nanoparticles with small size, which possess homogeneously mesoporous distribution, relatively large surface area and oxygen vacancies originated from Ce3+ ions, as well as the synergism of surface coordination unsaturated lattice oxygen and imprinting effect from bio-template. The CeO2-550 sensor exhibits high response (S = 16.5) and selectivity towards 100 ppm p-xylene vapors at 170 °C, and also presents low detection limit of 1 ppm, which are all significantly better than those of reported CeO2-based sensors. Therefore, mesoporous CeO2-550 nanosheets could be utilized as candidate for detecting trace p-xylene vapors.