Hydrothermal synthesis of oxidized g-C3N4 and its regulation of photocatalytic activity

Gradual oxidation of g-C3N4 was carried out using a mild hydrothermal method to obtain oxidized g-C3N4 (CNO). Besides occurring as N-O, oxygen also occurs in CNO as C=O and C-O, all ofwhich are of electron-withdrawing character and play a significant role in improving the photocatalytic performances of CNO materials. The photocurrent response of g-C3N4 treated for 12 hours, denoted as CNO-12, is ca. 10 times higher than that of raw g-C3N4, while the photocatalytic activity of CNO-12 is ca. 7 times higher than that of g-C3N4 in the degradation of Acid Orange 7.