In situ growth of MIL-88A into polyacrylate and its application in highly efficient photocatalytic degradation of organic pollutants in water

Highlights: • MIL-88A@polyacrylate was prepared via in situ growth on macroporous surfaces. • Functionalization by amine groups and space confinement controlled the structure. • Photocatalysis was enhanced by inhibiting recombination of photo-generated carriers. • MIL-88A@polyacrylate was highly stable and readily recycled owing to the molding. The development of a green, efficient, and reusable photocatalyst is of great importance for degradation of organic pollutants in water. Herein, MIL-88A@PA, a composite consisting of macroporous polyacrylate (PA) and metal organic frameworks (MOFs), was prepared by suspension polymerization, amine functionalization, and in-situ growth of MOFs. The nanosized MIL-88A of only 50–100 nm in diameter was reduced by approximately 90% owing to the control of heterogeneous nucleation and growth. More catalytic active sites were exposed and the photocatalytic activity of MIL-88A was significantly improved. The specific surface area of MIL-88A was increased from 132.79 to 219.78 m²/g owing to the decreased crystal size, and the corresponding degradation rate constant of Rhodamine B (RhB) was 9.4 times than that of pure MIL-88A. Under visible light irradiation, RhB could be completely degraded in 60 min using MIL-88A@PA with a loading amount of 45%. The degradation rate was still 97% after 5 cycles. The high photocatalytic activity of MIL-88A@PA can be attributed to the effective separation of photogenerated carriers, lower transfer resistance, and more active sites. The composite MIL-88A@PA material exhibits high stability and photocatalytic activity, which offers the potential in environmental cleaning.