“…41 Moreover, the C 1s peaks at about 286.3 and 288.2 eV in Pd/ N,S-F were attributed to C−O−C and O−CO, respectively, which possibly originated from the skeleton of the organic carbon chain and HCOOH. 42 In the N 1s spectrum of Pd/ N,S-F, only one peak appeared at 400.2 eV, corresponding to graphitic N (Figure S9). However, the N 1s signals of Pd/N,S-C and N,S-C could be divided into four peaks, pyridinic N (397.1/397.3 eV), pyrrolic N (398.0/398.2 eV), graphitic N (399.7/399.9 eV), and oxidized N (401.7/401.9 eV), 43 which indicated that the N element in biomacromolecules changed from the original graphite to form pyridine N (46.4/46.2%), pyrrole N (45.5/45.4%), and oxidized N (8.1/8.4%) after carbonization (Tables S1 and S3).…”