Preparation of Phosphorus-Doped Mesoporous G-C3n4 and its Photocatalytic Degradation of Tetracycline Hydrochloride

Abstract

P-doped tunnel-shaped carbon nitride was prepared for the first time using phosphonitrilic chloride trimer as P source and SBA-15 as template. The optimization experiments revealed that 20% P doped tunnel-shaped carbon nitride exhibited the best tetracycline hydrochloride (TC) degradation performance under visible light irradiation. The degradation rate constant was 0.23367 min-1, which was 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 experiments showed that h+ and ∙O2- were 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 was proposed, providing experimental data and theoretical basis for the practical application in polluted wastewater.

Keywords: photocatalysis, Silica templates, Tetracycline hydrochloride, Elemental phosphorus doping