Porous Graphitic Carbon Nitride Nanosheets by Pre-polymerization for Enhanced Hydrogen Evolution from Water Splitting under Solar Light
A facile and green method was developed to fabricate porous graphitic carbon nitride (g-C3N4) nanosheets by simple pre-polymerizing melamine. Porous structures were formed in polymerized g-C3N4 at 350∘C for 2h, which greatly enhanced the specifi surface area and pore volume, resulting in superior photocatalytic evolution. The hydrogen evolution rate was 11.2 higher than that of bulk g-C3N4 under visible light. The porous structure not only provided abundant active catalytic sites and cross-plane diffusion channels to facilitate the charge and mass transportation, but also promoted the charge separation in the photocatalytic reaction. This g-C3N4 is suitable for mass-production to generate hydrogen from water splitting.
Keywords: graphitic carbon nitride, photocatalytic, porous structures, prepolymerization, hydrogen evolution from water splitting
 Merschjann, C., Tyborski, T., Orthmann, S., et al. (2013). Photophysics of polymeric carbon nitride: An optical quasimonomer. Physical Review B, vol. 87, p. 205204.
 Algara-Siller, G., Severin, N., Chong, S. Y., et al. (2014). Triazine-based graphitic carbon nitride: A two-dimensional semiconductor. Angewandte Chemie International Edition, vol. 53, pp. 7450–7455.
 Fang, J. W., Fan, H. Q., Li, M. M., et al. (2015). Nitrogen self-doped graphitic carbon nitride as efficient visible light photocatalyst for hydrogen evolution. Journal of Materials Chemistry A, vol. 3, pp. 13819–13826.
 Ma, L. T., Fan, H. Q., Li, M. M., et al. (2015). A simple melamine-assisted exfoliation of polymeric graphitic carbon nitrides for highly efficient hydrogen production from water under visible light. Journal of Materials Chemistry A, vol. 3, pp. 22404–22412.
 Fang, J. W., Fan, H. Q., Zhu, Z. Y., et al. (2016). ”Dyed” graphitic carbon nitride with greatly extended visible-light-responsive range for hydrogen evolution. Journal of Catalysis, vol. 339, pp. 93–101.
 Ma, L. T., Fan, H. Q., Wang, J., et al. (2016). Water-assisted ions in situ intercalation for porous polymeric graphitic carbon nitride nanosheets with superior photocatalytic hydrogen evolution performance. Applied Catalysis B: Environmental, vol. 190, pp. 93–102.
 Zhao, Y. W., Fan, H. Q., Fu, K., et al. (2016). Intrinsic electric field assisted polymeric graphitic carbon nitride coupled with Bi4Ti3O12/Bi2Ti2O7 heterostructure nanofibers toward enhanced photocatalytic hydrogen evolution. International Journal of Hydrogen Energy, vol. 41, pp. 16913–16926.
 Ma, L. T., Fan, H. Q., Fu, K., et al. (2016). Metal-organic framework/layered carbon nitride nano-sandwiches for superior asymmetric supercapacitor. ChemistrySelect, vol. 1, pp. 3730–3738.
 Ma, L. T., Fan, H. Q., Fu, K., et al. (2017). Protonation of graphitic carbon nitride (g-C3N4) for an electrostatically self-assembling carbon@g-C3N4 core shell nanostructure toward high hydrogen evolution. ACS Sustainable Chemistry & Engineering, vol. 5, pp. 7093–7103.
 Tian, H. L., Fan, H. Q., Ma, J. W., et al. (2017). Noble metal-free modified electrode of exfoliated graphitic carbon nitride/ZnO nanosheets for highly efficient hydrogen peroxide sensing. Electrochimica Acta, vol. 247, pp. 787–794.
 Tian, H. L., Fan, H. Q., Ma, J. W., et al. (2018). Pt-decorated zinc oxide nanorod arrays with graphitic carbon nitride nanosheets for highly efficient dual-functional gas sensing. Journal of Hazardous Materials, vol. 341, pp. 102–111.
 Wang, C., Fan, H. Q., Ren, X. H., et al. (2018). Hydrothermally induced oxygen doping of graphitic carbon nitride with a highly ordered architecture and enhanced photocatalytic activity. ChemSusChem, vol. 11, pp. 700–708.
 Wang, C., Fan, H. Q., Ren, X. H., et al. (2018). Porous graphitic carbon nitride nanosheets by pre-polymerization for enhanced photocatalysis. Characterization,; vol. 139, pp. 89–99.