Bi, K co-doped graphitic phase carbon nitride for efficient photocatalytic H2O2 production

Abstract

The emerging photocatalytic production of hydrogen peroxide (H2O2) using graphitic carbon nitride (g-C3N4) has attracted a lot of attention for its potential applications in various fields. However, However, the catalytic activity of pure g-C3N4 is still limited. Herein, Bi, K co-doped g-C3N4 (BixKy-CN) was prepared by co-thermal polymerization of a mixture of potassium nitrate, bismuth nitrate, melamine, and urea. The obtained Bi3.6K3-CN composite possesses more negative conduction and valence band positions that can, to some extent, enhance photocatalytic performance by lowering the energy barrier of redox reactions and by enhancing electron absorption capacity. Additionally, the pyrolysis process of the potassium nitrate and bismuth nitrate has a considerable impact on the formation of the morphology of g-C3N4, generating a porous lamellar-structure with nitrogen defects, resulting in increased oxygen adsorption and utilization capacity. These synergistic effects enable Bi3.6K3-CN to exhibit excellent photocatalytic activity and cycling stability for H2O2 production. After 3 hours of visible light irradiation, the production of H2O2 catalyzed by Bi3.6K3-CN can reach 1207.72 μmol L-1, which is 57 times higher than that of pure g-C3N4.