Visible light-driven novel chlorine modified g-C3N4/ZnAl LDHs heterojunction with improved photodegradation activity towards organic pollutants

In this regard, an NH4Cl-modified g-C3N4/ZnAl-layered double hydroxides (CCN/LDHs) was successfully prepared by combining the calcine and hydrothermal treatment. The heterojunction samples are a hierarchical nanosheet structure self-assembled from the stacked hybrid flakes. The CCN/LDHs heterojunctions exhibited a superior synergistic effect between CCN and LDHs for decomposing typical tetracycline (TC) antibiotics in modulated seawater. The photodegradation kinetics constant of TC in seawater of CCN/LDHs hybrids showed 2.12 and 2.61 times higher than that of CCN and LDHs under visible light irradiation, respectively. The reusability and stability of the materials was also proved via cycling experiments. Additionally, the possible photo-degradation mechanism was illustrated based on the trapping experiments, EPR results and electron-hole pairs migration pathway analysis. With all results, this study complies the CCN/LDHs composite heterojunction and exhibits a tremendous synergistic effect for accelerating the separation of photogenerated charge carriers, which is beneficial for enhanced visible light photodegradation capacity. The exploration of CCN/LDHs in natural water systems (Xiangjiang River and underground water, Changsha, China) and heavy metal ions (Cr(VI)) demonstrated a great potential for its practical application.