Efficient water disinfection accelerated by polymerization-degree-controlled graphitic carbon nitride under visible light

In the quest for continuously raising the quality of drinking water, the exploration for effective photocatalysts to facilitate photocatalytic water disinfection remains an enduring challenge. Here, we demonstrate that by easily adjusting the polymerization degree of graphitic carbon nitride (g-C3N4), g-C3N4 itself can attain an exceptional photoactivity for disinfecting various waterborne bacteria. By synergistically integrating experimental investigations with density functional theory calculations, we propose that fine-tuning the polymerization degree of g-C3N4 confers remarkable attributes conducive to the specific generation of H2O2 through a two-electron reduction pathway. This ultimately culminates in the attainment of efficient water disinfection, that 7-log reduction in E. coli concentration is achieved within 180 min, in the absence of any additional cocatalyst. This work may shed light on developing highly efficient g-C3N4-based photocatalytic disinfectants for water disinfection applications.