N-doped synergistic porous thin-walled g-C3N4 nanotubes for efficient tetracycline photodegradation

Metal-free g-C 3 N 4 has received wide attentions because of the economy and environmental friendliness of it. However, the synthesis of simple and efficient g-C 3 N 4 modified materials is still challenging. In this study, series of novel N -doped porous thin-walled g-C 3 N 4 nanotubes (CNx) were synthesized through supramolecular self-assembly and thermal polymerization using melamine and aminourea hydrochloride as raw materials. SEM, XRD, XPS, etc. were used to analyze microscopic morphology and chemical structure of synthesized photocatalysts. PL spectra, EIS Nyquist curves and UV–vis DRS, etc. were applied to study the photoelectrochemical and optical properties. Besides, the performance of the synthesized catalysts was illustrated through TC photodegradation experiments, and the degradation rate of tetracycline (TC) by CN0.75 can reach to 93.0 % and the reaction rate constant was calculated to be 0.1347 min −1 . The excellent photocatalytic activity is primarily related to higher specific surface area and the formation of midgap states after N doped, which is conducive to the separation of charges. Finally, the possible pathways and mechanisms were proposed by determining the degradation intermediates and active species in the TC photodegradation process.