Enhanced photodegradation of paracetamol from water by cobalt doped graphitic carbon nitride

Paracetamol (PC), a pharmaceutical widely used in medical fields, is often discharged into water, causing harm to human health. Thus, it is imperative to develop photocatalysts which can efficiently remove PC from the wastewater. Graphitic carbon nitride (GCN) constitutes an important class of photocatalysts in the area of energy and environmental pollution control. Herein, we present a cobalt doped GCN (Co/GCN) to enhance the photodegradation of PC in the wastewater. Co/GCN significantly improved the separation of electrons and holes, narrowed band gap energy, and broadened the absorption of light. Even at high PC initial concentration, the Co/GCN exhibited a PC removal efficiency of 82.6% upon exposure to sunlight for 60 min, which is 1.7 time higher than that of undoped GCN. At low initial concentration of ≤1 mg/L, the Co/GCN was capable of decomposing PC with highest degradation efficiency reaching almost 100%. The kinetic result showed that the Co/GCN achieved the photodegradation rate 3.7 times higher than that of GCN. Furthermore, the Co/GCN can be recycled multiple times, indicating its potential use as photocatalyst for the treatment of pharmaceutical in wastewater.