Efficient removal of organic pollution via photocatalytic degradation over a TiO2@HKUST-1 yolk-shell nanoreactor

Currently, the design and development of yolk-shell nanoreactors for photocatalytic organic pollution removal have received increasing attention because of their unique architecture. In this work, we developed a novel TiO2@HKUST-1 yolk-shell nanoreactor for the removal of tetracycline (TC) and rhodamine B (RhB) under visible light radiation with clearly increased photocatalytic activity and stability. The degradation efficiency of RhB and TC over the TiO2@HKUST-1 composite was significantly higher than that of pure TiO2 and HKUST-1. Within 60 min, the RhB and TC elimination rates reached 95.2% and 92.40%, respectively when exposed to visible light radiation. After the fifth cycle, the photocatalytic TC degradation efficiency by TiO2@HKUST-1 remained at 89.02%. In TiO2@HKUST-1, a yolk-shell nanoreactor structure with intimate interfacial contact significantly increased the carrier density, specified surface area, and separation effect of photogenerated electron-hole pairs, all of which were highly helpful for enhancing the photocatalytic performance. Additionally, by using electron spin resonance (ESR) spin-trap technology, density function theory (DFT) calculations, positive species trapping studies, and other methods, a potential photocatalytic degradation mechanism was proposed. It was discovered that h+ and •OH were the main active species. In view of its excellent gas properties, TiO2@HKUST-1 was used as an adsorbent for Rh B solution. The effect of mixing time and different initial mass concentration on the adsorption effect was investigated, and the adsorption isotherm and kinetic equation were fitted to the experimental results. This work's successful augmentation can effectively remove organic contaminants and has a wide range of potential environmental applications.