Environmental Applications of 3D g-C₃N₄-Based Hydrogel with Synergistic Effect of Adsorption and Photodegradation

In this paper, g-C₃N₄-based hydrogel with a 3D network structure was synthesized via a simple and cheap reaction, using hydroxyethyl cellulose (HEC) and graphitic carbon nitride (g-C₃N₄) as the main materials. Electron microscope images revealed that the microstructure of g-C₃N₄-HEC hydrogel was rough and porous. The luxuriant scaly textures of this hydrogel were due to the uniform distribution of g-C₃N₄ nanoparticles. It was found that this hydrogel showed great removal ability of bisphenol A (BPA) through a synergistic effect of adsorption and photodegradation. The adsorption capacity and degradation efficiency of g-C₃N₄-HEC hydrogel (3%) for BPA were 8.66 mg/g and 78% under the conditions of C₀ = 9.94 mg/L and pH = 7.0, which were much higher than those for the original g-C₃N₄ and HEC hydrogel. In addition, g-C₃N₄-HEC hydrogel (3%) exhibited excellent removal efficiency (98%) of BPA (C₀ = 9.94 mg/L) in a dynamic adsorption and photodegradation system. Meanwhile, the mechanism of removal was investigated in depth. The superior batch and continuous removal capability of this g-C₃N₄-based hydrogel make it promising for environmental applications.