Fabrication of the metal-free biochar-based graphitic carbon nitride for improved 2-Mercaptobenzothiazole degradation activity

The present study describes a metal-free biochar-based photocatalyst of g-C₃N₄-C, in presence of an abundant fade magnolia as carbon precursor via facial in-situ together growth method. As a consequence, the g-C₃N₄-C shows a better degradation efficiency to 2-Mercaptobenzothiazole (90%) than pure g-C₃N₄ (49%) under the visible light. The improved photocatalytic performance of g-C₃N₄ is attributed to the biochar can significantly against the g-C₃N₄ reunion and stacking during high temperature treatment, because the biochar can act as the attachments that make the g-C₃N₄ flat and no accumulation, which will further increase the active sites. Additionally, photo-electrochemical measurements proved the separation efficiency of electron-holes of g-C₃N₄ is enhanced by introduced of biochar, due to its good electron transmission ability. Moreover, the ESR measurement and capture experiment further confirmed the active radicals on degradation of MBT are h⁺ and [rad]O₂ ⁻. This work may provide a promising approach for wastewater treatment by waste utilization of solid biomass and increasing the photocatalytic performance of g-C₃N₄.