Plasma-Tuned nitrogen vacancy graphitic carbon nitride sphere for efficient photocatalytic H₂O₂ production

Graphitic carbon nitride (CN) is a promising photocatalyst for sustainable energy conversion. Meanwhile, N vacancies are useful for H₂O₂ generation; however, they are hard to control. In this study, the N vacancy CN sphere (NVCNS) is synthesized by H₂ plasma treatment to tune the NV. The as-synthesized NVCNS exhibits an efficient and stable photocatalytic H₂O₂ yield of 4413.1 μmol g_cat^-1h^-1, which is 2.5 and 4.6 times higher than that of CNS (1766.4 μmol g_cat^-1h^-1) and bulk CN (956.6 μmol g_cat^-1h^-1), respectively, using a Xe lamp with an intensity of 100 mWcm^-2. In particular, the charges recombination rate is remarkably reduced by introducing N defect state, promoting electron accumulation and O₂ adsorption, through theoretical calculation and experiments. Furthermore, the NV creates abundant unsaturated sites and induces strong interlayer interactions, leading to effective electronic excitation and the promotion of charge transport.