CuS Nanoparticles/MIL-125(Ti) Heterojunction as Photocatalyst for the Photodegradation of Tetracycline

Abstract

is an attractive material in photocatalysis due to its notable characteristics, including its expansive specific surface area, porous structure, high thermal stability, and chemical resistance. Unfortunately, the high electron−hole recombination rate and weak utilization of visible light restrict its practical application. Here, a CuS nanoparticle/MIL-125(Ti) heterojunction with a compact interface contact was prepared by a facile hydrothermal method for photocatalytic tetracycline degradation. The aligned internal electric field and interface structure of the CuS nanoparticles/MIL-125(Ti) heterojunction show promise in effectively addressing the aforementioned challenges. Detailed characterization showed that CuS nanoparticles/MIL-125(Ti) generated a redshift in light absorption, and the photogenerated electron−hole recombination rate was reduced by about 67.5% compared with MIL-125(Ti), greatly improving the photocatalytic performance. Photogenerated electrons between the conductive band of CuS nanoparticles and MIL-125(Ti) with Ti 4+ to Ti 3+ reduction contributed to the enhanced photocatalytic performance, and the generated active species (h + , •OH, •O 2 − ) degraded tetracycline rapidly. The kinetic parameters of tetracycline degradation by the CuS/MIL-125(Ti) composite with an optimal doping amount are 12.7 and 7.9 times higher than those of a single component.