Nitrogen-doped coatings on carbon nanotubes and their stabilizing effect on supported Pt nanoparticles
For the preparation of the coating the CNTs were dispersed in a 30 wt% solution of 3MBP-dca in deionised water by sonication. The resulting black slurry was filtered by vacuum filtration and the black residue in the filter was washed with 50 mL of ethanol to remove excess IL. The residue was subsequently placed in ceramic crucible and thermally treated in a furnace under constant argon flow to 1000 °C applying a heating rate of 100 K h -1 . After 1 h at 1000 °C the sample was allowed to cool down to room temperature and subsequently pestled for further use.
Summary of ISO/TC 201 Standard: VII ISO 15472 : 2001—surface chemical analysis—x‐ray photoelectron spectrometers—calibration of energy scales
This international standard specifies a method for calibrating the binding energy scales of x‐ray photoelectron spectrometers, for general analytical purposes, using unmonochromated Al or Mg x‐rays or monochromated Al x‐rays. It is only applicable to instruments that have an ion gun for sputter cleaning. This international standard further specifies a method to establish a calibration schedule, to test for the binding energy scale linearity at one intermediate energy, to confirm the uncertainty of the scale calibration at one low and one high binding energy value, to correct for small drifts of that scale and to define the expanded uncertainty of the calibration of the binding energy scale for a confidence level of 95%. This uncertainty includes contributions for behaviour observed in inter‐laboratory studies but does not cover all of the defects that could occur. This international standard is not applicable to instruments with binding energy scale errors that are significantly non‐linear with energy, to instruments operated in the constant retardation ratio mode at retardation ratios of <10, to instruments with a spectrometer resolution worse than 1.5 eV or to instruments requiring tolerance limits of ±0.03 eV or less. This international standard does not provide a full calibration check, which would confirm the energy measured at each addressable point on the energy scale and would have to be performed in accordance with the manufacturer's recommended procedures. © Crown Copyright 2001. Published by John Wiley & Sons, Ltd.
XPS: binding energy calibration of electron spectrometers 4—assessment of effects for different x‐ray sources, analyser resolutions, angles of emission and overall uncertainties
A detailed analysis is made of the binding energy calibration of X-ray photoelectron spectrometers when using monochromated Al Kα x-rays or unmonochromated Al or Mg Kα x-rays. The binding energies of the peaks for Cu 2p3/2, Ag 3d5/2 and Au 4f7/2, as well as for the Ni Fermi edge, are measured at high resolution using monochromated Al Kα x-rays. The apparent binding energy shifts of the peaks are then calculated for this source, and also for the Al and Mg unmonochromated x-ray sources, using full synthetic Kα x-ray structures, as a function of Gaussian spectrometer energy resolutions in the range 0.2–1.5 eV. For all three x-ray sources, the relative binding energies for the Cu 2p3/2 and Au 4f7/2 peaks are contained within ±0.015 eV but the effects for Ag 3d5/2 are stronger and the containment range must be increased to ±0.026 eV. Further data and calculations are provided for surface core-level shifts and here it is found necessary to restrict emission angles to 56° for all the peak separations to be restricted to the above range of ±0.026 eV. Other instrumental effects may give rise to additional larger or smaller effects. Non-optimized settings for monochromators can show further shifts of up to ±0.2 eV. 
 
The uncertainties associated with the above calibration are then analyzed to show how the uncertainty at 95% confidence varies across the binding energy range. Example calculations show that seven repeats of both the Cu 2p3/2 and Au 4f7/2 binding energies may be used to define the peak repeatability and that one or two measurements can then be made for each calibration peak to define the calibration. The precise number of measurements to be used depends on the peak energy repeatability and the required confidence limits for the calibration. In practical situations, however, it is likely that the greatest uncertainty in the binding energy scale arises from the drift in the electronics between calibrations. © 1998 John Wiley & Sons, Ltd.