Carbon nitride coupled with Ti3C2-Mxene derived amorphous Ti-peroxo heterojunction for photocatalytic degradation of rhodamine B and tetracycline

Abstract

Exploring the solar-driven photocatalyst for antibiotic and dye degradation has been confronted with a great challenge. In this study, a novel and original photocatalyst derived from the g-C3N4/amorphous Ti-peroxo complexes (CATC) heterojunction was successfully synthesized towards Rhodamine B (RhB) and tetracycline (TC) degradation under visible light irradiation (λ>420 nm). Based on the special photocatalytic activity, Ti3C2-Mxene acted as the starting precursor of amorphous Ti-peroxo complexes via one-step H2O2 oxidation route. Multiple characterization techniques were applied to explore the crystal structure, element composition, and photoelectrochemical property of photocatalyst. As expected, the modified photocatalyst possessed a favorable photocatalytic performance towards the preferable reaction rate for RhB (0.0483 min−1) and TC (0.0208 min−1) degradations, which were 16.65 times and 69.3 times higher than that of pure g-C3N4 (CN) material, profiting from the generated direct Z-scheme heterojunction with favorable redox capacity. Here, h+,∙O2- and ∙OH were verified as typical active radicals for RhB and TC degradation through free radical quenching experiments and electron spin resonance characterization. Degradation intermediate products were also confirmed by high performance liquid chromatography–mass spectrometer (HPLC-MS). The effects of initial pH and ionic strength on RhB and TC photocatalytic degradation performances were discussed. In addition, a preferable reusability and stability performance ensured the modification photocatalyst had a great application potential in wastewater treatment. This study provided a unique avenue through one-step method for the construction of g-C3N4 and Mxene based photocatalyst towards the degradation of antibiotics and dyes from wastewater.