A Fe₃O₄@COOH-activated carbon (Fe₃O₄@CFC-COOH) was prepared via carboxyl-functionalization of the activated carbon derived from feather waste, followed by co-precipitation of Fe²⁺ and Fe³⁺ under alkaline conditions. This hybrid organic–inorganic porous compound was applied for the in-situ synthesis of TMU-16 MOF and, subsequently, further engaged as support for immobilizing of Cu nanoparticles. The multi-application of the as-synthesized nanocomposite was investigated in the synthesis of tetrahydrobenzo[b]pyrans derivatives and the removal of methylene blue from aqueous media. The adsorption process fitted well with the Freundlich model and has followed the pseudo-second-order model kinetic model. Also, the Fe₃O₄@CFC-COOH@TMU-16@Cu exhibited high catalytic activity in the synthesis of tetrahydrobenzo[b]pyran derivatives.

A Fe₃O₄@activated carbon-COOH (Fe₃O₄@CFC-COOH) was prepared via carboxyl-functionalization of the activated carbon derived from feather waste, followed by co-precipitation of Fe²⁺ and Fe³⁺ under alkaline conditions. This hybrid organic–inorganic porous compound was applied for in-situ synthesis of TMU-16 metal–organic framework and, subsequently, further engaged as support for immobilizing of Cu nanoparticles. The multi-application of the as-synthesized nanocomposite was investigated in the synthesis of tetrahydrobenzo[b]pyrans derivatives and the removal of methylene blue from aqueous media. The maximum absorption percentage (Re) for the removal of methylene blue was 96%. The adsorption process fitted well with the Freundlich model and has followed the pseudo-second-order kinetic model. Also, the Fe₃O₄@CFC-COOH@TMU-16@Cu exhibited high catalytic activity in the synthesis of tetrahydrobenzo[b]pyran derivatives with a wide range of aldehydes bearing electron-donating and electron-withdrawing groups.