A Trojan Horse Approach toward Green Synthesis of Cu-BDC Patterned Carboxymethyl Cellulose Beads

Metal–organic frameworks (MOFs) are promising for environmental remediation, but their nanosize limits practical application. Here, we used a green and scalable technique to grow copper benzene-1,4-dicarboxylate (Cu-BDC) MOFs on carboxymethyl cellulose (CMC) macro-sized beads. We dropped a solution of 2% w/v CMC containing aniline and 1,4-benzenedicarboxylic acid into an aqueous anhydrous copper acetate solution. The resulting 1.32 ± 0.11 mm-sized beads contained sheet-like folds patterned with 483.78 ± 7.29 nm-sized rice-like Cu-BDC crystals. The presence of aniline was important in the formation of the Cu-BDC complex, providing a [Cu–aniline] complex as a seeding template. We investigated the effect of aniline concentration, temperature, and time using a 10-experiment full factorial screening design. Increasing the aniline concentration enhanced bead crystallinity and size. Longer time and higher temperature increased crystallinity but reduced bead size due to inward constriction from surface reactions. Our green method yields Cu-BDC beads, offering ease of handling and separation, making them ideal for environmental remediation.