Pomelo biochar as an electron acceptor to modify graphitic carbon nitride for boosting visible-light-driven photocatalytic degradation of tetracycline

Abstract In this study, biochar (BC) derived from pomelo was prepared via a high-temperature calcination method to modify the graphitic carbon nitride (g-C3N4) to synthesize the BC/g-C3N4 composite for the degradation of the tetracycline (TC) antibiotic under visible light irradiation. The experimental results exhibit that the optimal feeding weight ratio of biochar/urea is 0.03:1 in BC/g-C3N4 composite could show the best photocatalytic activity with the degradation rate of tetracycline is 83% in 100 min irradiation. The improvement of photocatalytic activity is mainly attributed to the following two points: (i) the strong bonding with π-π stacking between BC and g-C3N4 make the photogenerated electrons of light-excited g-C3N4 transfer to BC, quickly and improve the separation efficiency of carriers; (ii) the introduction of BC reduces the distance for photogenerated electrons to migrate to the surface and increases the specific surface area for providing more active sites. This study provides a sustainable, economical and promising method for the synthesis of photocatalytic materials their application to wastewater treatment.