Synthesis of MgAl LDH/Acidified g-C3N4 Heterojunction Photocatalyst for Improved Tetracycline Hydrochloride Degradation Activity

A novel heterojunction photocatalyst consisting of three-dimensional (3D) flower-like MgAl LDH and acidified g-C 3 N 4 (CN-H) was first developed by a simple facile coating method. The obtained MgAl LDH/CN-H samples were thoroughly characterized by powder X-ray diffraction (XRD), UV–Vis diffuse reflectance spectroscopy (DRS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), photoluminescence spectroscopy (PL), X-ray photoelectron spectroscopy (XPS), electrochemical impedance spectroscopy (EIS) and Brunauer–Emmett–Teller (BET) analyzer. The detailed results demonstrated that g-C 3 N 4 could transform from a generally two-dimensional layered structure into special cavity-like structure after acid treatment. CN-H increased specific surface to expose more active reaction sites in comparison to pristine g-C 3 N 4 . MgAl LDH and CN-H with matched band gaps were tightly bonded to form heterojunction structure by strong electrostatic intercalation. The combination could obviously boost the separation of photogenerated carriers. The as-prepared MgAl LDH/CN-H exhibited high photocatalytic performance in the degrading on typical antibiotic tetracycline hydrochloride (TC ⋅ HCl), of which degradation rate was 6.5 and even 22 times higher than that of MgAl LDH and pristine g-C 3 N 4 , respectively. The synthesis of MgAl LDH/CN-H heterojunction photocatalyst could have some positive suggestions for the rational construction of new photocatalysts and also has great application prospect in the degradation of environmental pollutants.