The XPS Zn2p spectra of the catalyst after the adsorption of FLU and MeB are illustrated in Figure . The two peaks related to the Zn2p3/2 and Zn2p1/2 were observed at 1044.9 eV and 1021.9, respectively . No significant change in the position of these two peaks after immersing in MeB and FLU dyes. After adsorption, the XPS C1s spectrum envelope was deconvoluted, as illustrated in Figure . Peaks attributed to graphitic carbon, C-O or C-N and C=O or C=N were fixed at 284.5 eV, 286.2 eV, and 288.8 eV, respectively . The FWHM of these peaks were 1.8 eV, 2.1 eV, and 2.9 eV, respectively. These deconvolution parameters were also applied during the deconvolution of the C1s spectrum of ZnO@N-doped C before adsorption (Figure ). A new deconvoluted peak was observed at 288.0 eV after MeB adsorption, which is attributed to carbon that is directly attached to SO3 -. The abundance of C-N components increased after the adsorption of MeB, and this increase was attributed to the C-N components of MeB. Figure illustrates the XPS N1s spectra, where the abundance of pyrrole-like nitrogen at 399.2 eV increased after adsorption of MeB dye due to the addition of N-H components of MeB.