Scheme 1. Schematic illustration for the fabrication of B-CNT, P-CNT, and S-CNT.

Fig. 1. (a) SEM image of MCS crystals; (b, c) SEM and TEM images of CNT; (d) nitrogen adsorption-desorption isotherms of BCN and CNT.

Fig. 2. Differential pore size distribution (a) and cumulative intrusion (b) curves of samples.

Fig. 3. SEM images of B-CNT (a-c), P-CNT (d-f), and S-CNT (g-i) and their corresponding element mappings.

Fig. 4. XRD patterns of BCN, CNT, B-CNT, P-CNT, and S-CNT.

Fig. 5. (a, b) FT-IR spectra and (c-g) XPS spectra of samples.

Fig. 6. The schematic diagram of B, P, and S atoms doping sites in the CN lattice.

Fig. 7. (a) Photocatalytic production of H2O2 with samples under the irradiation of simulated sunlight; (b) the concentration of H2O2 over different samples in the first-hour irradiation; (c-e) the kinetic fitting for formation rate constants (kf) and decomposition rate constants (kd) of B-CNT, P-CNT, and S-CNT.

Fig. 8. The role of O2, alcohol, and •O2- species on the H2O2 generation.

Fig. 9. The optical properties of samples and their corresponding bandgap (inset).

Fig. 10. (a) Mott-Schottky plots, (b) the band structure alignments, (c) transient photocurrent response, and (d) electrochemical impedance spectroscopy plots of samples.

Fig. 11. The plausible mechanism for the photocatalytic H2O2 generation.