Invited paperEnhanced photo-electrochemical, photo-degradation and charge separation ability of graphitic carbon nitride (g-C3N4) by self-type metal free heterojunction formation for antibiotic degradation

•Self-type metal free hetrojunction created between two different types of graphitic carbon nitride.•The prepared self-composite possess enhanced photochemical, photo-degradation ability.•Graphitic carbon nitride self-type composite degraded the TC-HCl under visible light irradiation.

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-C3N4 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.

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