“…The peak at 284.6 eV corresponds to the CC/C–C bonds and the peak at 285.3 eV can be correlated with C–C/C–N/C–P bonds, while the peaks at 286.6 and 289.3 eV can be attributed to the presence of C–O/CN/CP and CO/O–CO, respectively. The deconvoluted O 1S spectra (depicted in Figure b) comprise two peaks at 531.8 and 533.3 eV, which indicate the presence of C–O/O–(N/P) and CO/PO groups, respectively. , The deconvoluted XPS spectra of N 1S (Figure c) show the appearance of four different characteristic nitrogen functionalities: intense graphitic nitrogen at 402.1 eV, pyrrolic nitrogen at 400.7 eV, amino nitrogen at 399.6 eV, and a very small extent of pyridinic nitrogen at 398.4 eV. − Furthermore, the deconvoluted XPS spectra of P 2P (Figure d) consist of two peaks at 134.4 and 135 eV, which correspond to the P–C and PO bonds, respectively. − In addition, the FTIR spectra (Figure S3) at the longer wavenumber region show a broad and intense peak at around 3032–3674 cm –1 , which can be attributed to the combined stretching vibration of the −NH/–OH functional groups on the surface. The low intense peaks in the region of 2800–2940 cm –1 correspond to the C–H stretching vibration.…”