Lacey carbon film

Transmission electron microscopy studies of the supported catalysts were performed in a JEOL JEM 2010 operating at 200 kV equipped with EDS capabilities. The microscope is equipped with an ultrahigh resolution polar piece (point resolution 1.9 A). Specimens for the TEM studies were prepared by depositing a drop of aqueous suspension onto 300 mesh Cu grid coated with a lacey carbon film. The Pd loadings of the different catalysts were determined by ICP-AES. 

Figure 7.9. (a) A comparison of TEM grid mesh sizes (b) Illustration of the float off method to prepare carbon-coated TEM grids (c) Comparison of a lacey carbon coating with holey carbon films deposited onto TEM grids. 

For high-resolution TEM analysis, the most appropriate materials are holes in the range of about 0.2-10 pm, which reduces the absorption and scattering of the electron beam and help to improve the quality of the signal. For particles with little contrast, holey films coated with an extra layer, ultrathin of carbon can improve the quality of images. The so-called lacey films are quite recommended for electron diffraction images [31]. 

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