Additionally, the XPS technique has been used to examine Pb(II) adsorption on the SBA15–0.3NH2 material. The binding energies of Si 2p, O 1s, N 1s and Pb 4f7/2 core electrons are compiled in Table 2. Fig. 10 shows the overall spectra of SBA15–0.3NH2sample before and after lead adsorption from the solutions containing 200 and 400 ppm of Pb(II) ions. For the Pb-containing adsorbents, the photoelectron peaks of oxygen can be seen next to the characteristics peaks of lead and silica. As expected, all adsorbents show the peak at about 532.9 eV assigned to oxygen in Si–O–Si. With exception of the Pb 4f peak, the overall spectrum of pure adsorbent shows the same peaks with similar intensities as Pb-containing adsorbents. Only the detail spectra of the Pb 4f show differences in the latter samples. The C 1s peak at 284.9 eV is due to the usually present carbon surface contaminant [62].