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Two-dimensional graphitic carbon nitrides (2D g-C3N4) are promising photocatalysts for water splitting to hydrogen due to their non-toxicity and high stability. However, the bulk g-C3N4 has some intrinsic drawbacks, such as rapid electron–hole recombination and low charge-carrier mobility, resulting in poor photocatalytic activity. Here, 2,4-diamine-6-phenyl-1,3,5-triazine was employed as a precursor to regulating the assembly of melamine and cyanuric acid in water. The resulting g-C3N4 not only improved the visible light absorption and electron–hole separation but also provided more catalytic sites for enhanced photocatalytic hydrogen evolution. The modified g-C3N4 (CNP10-H) showed a hydrogen-releasing rate of 2184 μmol·g−1·h−1, much higher than the bulk g-C3N4. [ABSTRACT FROM AUTHOR]

A novel metal free, graphitic carbon nitride self-type heterojunction was successfully created. A self-type heterojunction between two different kind of graphitic carbon nitride with a promote charge separation ability, one was prepared by solvothermal using the dicyandiamide as precursor and other was prepared by direct heating from melamine precursor. This synthesis process is facile, economical and environment friendly. The confirmation of synthesis and heterojunction formation was based on the X-ray-Diffraction, Transmission electron microscopy, Scanning electron microscopy, Fourier transform infrared spectra, X-ray photoelectron spectroscopy and photocurrent. The potential difference in heterojunction between different types of g-C 3 N 4 is the main acting power for the proficient separation and transformation of photo generated charges. Degradation results indicated that, the removal of antibiotic from effluents, graphitic carbon nitride heterojunction (GCN-DM) pointedly enhanced the visible light catalytic activity over solo graphitic carbon nitride (GCN-D, GCN-M). The improved photocatalytic behaviour of heterojunction may be due to charge separation and transfer ability with prolong lifetime of photo-generated charge carrier. The results also indicated that the optical and surface area properties also play a significance role in enhancement of photo-catalytical ability of target photo-catalyst. [ABSTRACT FROM AUTHOR]