Facile bottom-up preparation of Cl-doped porous g-C3N4 nanosheets for enhanced photocatalytic degradation of tetracycline under visible light

Utilizing highly efficient and stable photocatalysts to treat residual antibiotic pollutants in water is of great significance. In this work, Cl-doped porous g-C3N4(CN-Cl) was prepared by a facile bottom-up synthetic route for photocatalytic degradation of tetracycline (TC). The synthesized samples were analyzed by a series of characterization methods. The optimum photocatalytic activity under visible-light irradiation for CN-Cl with the precursor mass ratio of ammonium chloride to melamine is 1:1 (92% degradation within 120 min), which is up to 2.4 times as high as that of pure CN. The remarkable improvement of the photocatalytic activity of CN-Cl is mainly due to the following three reasons: (i) Cl-doped element can help to regulate the electronic structure of CN; (ii) the prepared CN-Cl samples have larger specific surface area than pure CN, thus providing more reactive sites; (iii) Cl-doped element can inhibit the recombination of photo-induced electron and holes of CN. This work may provide a facile bottom-up strategy to improve the photocatalytic performance of CN for the mitigation of environmental problems.