Preparation of phosphorus-doped mesoporous g-C3N4 and its photocatalytic degradation of tetracycline hydrochloride

P-doped tunnel-shaped carbon nitride is prepared for the first time using phosphonitrilic chloride trimer as P source and SBA-15 as template. The optimization experiments reveal that 20% P doped tunnel-shaped carbon nitride exhibited the best tetracycline hydrochloride (TC) degradation performance under visible light irradiation. The degradation rate constant is 0.23367 min−1, which is around 3 and 30 times faster than that of carbon nitride without P doping (0.07223 min−1) and without SBA-15 as template (0.00078 min−1). Radical capture experiment shows that h+ and ∙O2− are the main reactive radicals in the photocatalytic degradation process. The doped P element can increase the formation rate of ∙O2− and reduce the combination of photogenerated electron-hole pairs due to the presence of electron capture centers. The photocatalytic mechanism of P-doped tunnel-shaped carbon nitride is proposed, providing experimental data and theoretical basis for the practical application in polluted wastewater. [Display omitted] •A facile vapor deposition method is used to synthesize g-C3N4.•SBA-15 was used as templates to synthesize tunnel structure.•The P located in the material facilitates the separation of electrons and holes.•The sample exhibits competitive performance with other g-C3N4 based catalysts.