Rapid water purification using modified graphitic carbon nitride and visible light

Developing simple yet highly efficient photocatalytic systems is of fundamental importance to implement photocatalysis into practical water treatment applications. Unfortunately, despite intense efforts over the past few decades, the activities of the currently-reported photocatalysts are still far from meeting the requirements of industrial applications. Here, we show that by facilely tuning the reaction parameter for synthesizing graphitic carbon nitride (g-C3N4), g-C3N4 can in itself achieve an extremely high photocatalytic activity towards the decomposition of several recalcitrant organics. The synthesized g-C3N4 significantly outperforms the extensively studied P25 TiO2 under both visible-light and full arc illumination, and its catalytic activity is even comparable or better than that of the representative g-C3N4-based nanocomposites previously reported, with a much lower catalyst consumption. Furthermore, only 5 min of ultrasonic pretreatment is required to achieve the excellent activity for the g-C3N4 photocatalyst, indicating its immense potential in real-world photocatalytic water treatment operations.