A hybrid block consisting of covalent triazine frameworks and GO aerogel with switchable selectivity between adsorption of UV filters and regeneration under sunlight

Abstract

UV filters, a kind of personal care product (PCP), are intractably degraded using conventional processes because of their trace concentration in the environment. The exploration of high-performance, stable, and reusable materials for the highly efficient removal of UV filters is of great importance. In this study, a series of three-dimensional graphene oxide-covalent triazine-based frameworks aerogels (3D GO-CTF) prepared with different concentration ratios were designed to remove trace concentrations of benzophenone (BP), 2,4-dihydroxybenzophenone (BP-1) and 2-hydroxy-4-methoxybenzophenone (BP-3) from water, which are regenerated by sunlight. 3D GO-CTF not only adsorbs UV filters with high efficiency (0.0311 ± 0.0009 g/(μmol·s)) and capacity (2963.708 ± 4.637 μmol/g), but can also be regenerated with an extremely high percentage recovery of 90–95% in the 4th cycle. These 3D GO-CTF materials exhibit switchable selectivity between the adsorption of the UV filters and regeneration of the 3D GO-CTF by regulating the content of GO to function as the adsorbent and CTF for photocatalytic regeneration. Moreover, the high reusability and extreme stability of the 3D GO-CTF aerogels were verified over seven cycles of night-day testing in a real water matrix, which demonstrated their potential application in the efficient removal of micropollutants from the environment.