Chemical Vapor Deposition Growth of MoS2 on g-C3N4 Nanosheets for Efficient Removal of Tetracycline Hydrochloride.

MoS2 was vertically grown on g-C3N4 nanosheets by chemical vapor deposition to prepare nanocomposites named MS-CN samples. Because of a large-surface area of 545.2 m2·g-1 and a total pore volume of 1.7 cm3·g-1, the sample MS-CN revealed fast and large adsorption capacity for tetracycline hydrochloride (TCH). The adsorption kinetics model proved that TCH could be rapidly adsorbed within 5 min, and chemical adsorption was dominant. For single-component adsorption of TCH, the maximum adsorption capacity was ∼154 mg/g. The monolayer adsorption was carried out on the surface of MS-CN. Both of the film and intra-particle diffusion were considered as significant processes to facilitate adsorption. Thermodynamic parameters indicate that the adsorption of TCH is a spontaneous endothermic process. The adsorption of TCH was highly pH-dependent. The maximum adsorption capacity of TCH was obtained in the case of pH ∼ 7. After four adsorption and desorption cycles, MS-CN still maintained well-adsorption performance. Multiple adsorption mechanism, pore filling, electrostatic force, π-π conjugation, and hydrogen bonding interactions were studied. Because of fast adsorption, large adsorption capacity, and high stability, it is a promising adsorbent for antibiotics.