Amino functional SBA-15 assisted NU-1000 for the rapid and efficient adsorption of tetracycline antibiotics†

The pollution of antibiotics in water resources was addressed by constructing an SBA-15@NU-1000 composite via a one-pot hydrothermal method, and the specimen was characterized using scanning electron microscopy, transmission electron microscopy, powder X-ray diffraction, small-angle X-ray diffraction, thermogravimetric analysis, N₂ sorption isotherms as well as Fourier transform infrared and X-ray photoelectron spectroscopy. The amino functional group of SBA-15 contributed to its successful combination with NU-1000, and the doping ratio of SBA-15 affected the adsorption capacity of tetracycline. The SBA-15@NU-1000 composite not only exhibited a faster adsorption rate but also higher adsorption capacity than pure NU-1000. In particular, the equilibrium adsorption time for tetracycline decreased from 40 to 10 min, and the adsorption capacity for tetracycline increased from 356 to 424 mg g⁻¹. The superior adsorption performance of SBA-15@NU-1000 compared with that of NU-1000 was attributed to the amino functional SBA-15 directing the growth of NU-1000 on its outer surface, which minimized the particle size of NU-1000 and increased the production of adsorption sites. This study demonstrated the effectiveness of successfully combining a metal–organic framework (MOF) with a mesoporous silica support, either grown in the interior channel or on the exterior surface, to promote the adsorption performance of MOFs.