Quanta 600 microscope

Paraffin spheres were observed with a LV100ND Eclipse Nikon microscope (Tokyo, Japan) equipped with a 5MPix CCD camera to control the shape and the diameter of the spheres. Concerning cellular carbon monoliths, cell structure and average size, as well as average window diameter, i.e., the size of the circular holes connecting the cells, were determined by scanning electron microscopy (SEM) observations with a FEI Quanta 600 microscope (Hillsborough, OR, USA). For that purpose, CRF samples were placed on a carbon-coated sample holder and sputtering-coated under vacuum with an extremely thin carbon layer in a metallisation system. For all of the samples, two modes of observations using detectors of secondary electrons (SE) and backscattered electrons (BSE) were used. SE indeed highlight the topological contrast, and were thus the most suitable for estimating the average cell diameters, whereas BSE were the best for visualising cell windows and measuring their diameters. Figure 1 shows one example, justifying the use of two different electron detectors. Average cell and window diameters were estimated with Image Pro-Plus 6.0 software (Rockville, MD, USA), based on a collection of more than 200 cells and windows. After calibration, the software automatically provided the average sizes of selected pores.

The structure and phase identification of the recovered electrodeposits were investigated using the following: (i) An X-ray diffraction analysis device (PanAlytical MPDPRO diffractometer) equipped with CuKα radiation of 1.540 Å over the range 20°–80° equipped with a linear X'Celerator detector using copper anticathode (λKα1/α2 = 1.540560/1.544330 Å). X-ray diffraction patterns are obtained in the 2θ range of 20–80°; the step size is 0.02; and the time per step is 30 s. (ii) A scanning electron microscope (SEM), an FEI Quanta 600 microscope and (iii) energy-dispersiveX-ray (EDX) coupled with the SEM were used.

SEM images were partly acquired using a Teneo SEM from Thermo Fisher Scientific (Thermo Fischer Scientific, Waltham, MA, USA). The measurements were conducted at Enabling Technologies. Other images were acquired using a Hitachi S4800 FESEM or a FEI quanta 600 microscope. For sample preparation one droplet of the particle dispersion was placed on a silicon wafer and dried at room temperature. The samples were sputtered with gold. Particle diameters and standard deviations from SEM images were determined using MATLAB. For average diameter and standard deviation at least 200 particles per sample were measured.