Self-assembly synthesis of petal-like Cl-doped g-C3N4 nanosheets with tunable band structure for enhanced photocatalytic activity

Abstract Efficient separation of photo-induced charge carriers is highly desired for improving photocatalytic activity. Herein, morphology control and element doping are adopted to overcome the shortcomings of insufficient contact with pollutants and limited light-harvesting capability of the pristine g-C3N4. Petal-like Cl-doped g-C3N4 nanosheets are fabricated by a flexible self-assembly route using melamine and cyanuric as precursors, with different amounts of NH4Cl added to adjust the chlorine doping ratio. Benefiting from the enlarged specific surface area (98.330 m2 g−1), tunable band structure and the effective charge separation, the prepared chlorine doping g-C3N4 nanosheets show obviously higher efficiency in the removal of rhodamine B (90 min, 94.3 %) and tetracycline hydrochloride (120 min, 65.7 %), with degradation kinetic rates about 15.8 and 2.3 times than that of pristine g-C3N4. The supramolecular self-assembly and chlorine doping display a noticeable synergy on enhancing the photocatalytic performance, enabled g-C3N4-based nano-sized photocatalysts to be highly competitive candidates for pollutant elimination.