A novel solar-triggered MIL-125(Ti)/g-C3N4/SA composite aerogel with high catalytic activity for degradation of organic contaminants

Abstract Sodium alginate (SA) aerogels have shown outstanding potential as regenerative adsorbent materials in the field of wastewater purification. Although SA aerogel adsorption has been demonstrated as a simple and resultful method for removing dyes, it has the limitation that it only transfers or concentrates dyes on the adsorbate, and does not actually degrade them. In this study, a three-dimensional (3D) MIL-125/g-C3N4/SA (CNTi-125@SA) composite aerogel with visible light photocatalytic activity was achieved for photocatalytic degradation of organic dyes, via in-situ growth, blending and freeze-drying strategy. The results demonstrate that CNTi-125@SA has high catalytic activity for the dyes rhodamine B (RhB), methylene blue (MB) and methyl orange (MO), and the degradation rate can reach up to 99.23%. Impressively, the composite aerogel exhibits excellent antibacterial ability, and the antibacterial rate can reach up to 100% against E. coli. In addition, the developed composite aerogel has excellent reusability and stability, and the degradation efficiency can still reach 85% after seven repeated tests. Owing to their high catalytic activity, excellent antibacterial properties and stability, the CNTi-125@SA composite aerogel can be potentially used in a wide range of dye wastewater purification.