“…The binding energies of the latter two N atoms in CeO 2 /PCN composite are higher (N−(C) 3 : 399.9 eV; C=N−C: 398.5 eV) than pristine PCN without illumination but lower (N−(C) 3 : 399.5 eV; C=N−C: 398.1 eV) under illumination, suggesting that these N elements actually act as the electron donor in the absence of illumination but electron acceptor under illumination. Additionally, the high‐resolution Ce XPS spectra of pure CeO 2 can be fitted into several peaks at 881.9, 886.3, 900.2, and 904.8 eV, which can be assigned to the V, V′, V′′′, and U′ states of Ce elements, respectively . Figure c shows that after the formation of close contact between CeO 2 and PCN in darkness, the binding energies (V 881.5 eV, V′ 885.8 eV, V′′′ 899.8 eV, U′ 904.3 eV) of Ce atoms in the CeO 2 /PCN composite decrease compared to the pure CeO 2 , revealing that it is the electron acceptor in the absence of illumination.…”