ZIF-67 functionalized bacterial cellulose films for light-enhanced NaBH₄-assisted catalytic reduction of nitrobenzene

This study reports on the synthesis of ZIF-67 and its in situ growth on bacterial cellulose (BC) films produced through a green fermentation method. The resulting BCZIF-67 composites were characterized by N₂ sorption analysis, FTIR, XRD, SEM-EDS, and UV-vis diffuse reflectance spectroscopy. The results supported the successful incorporation of ZIF-67 into the BC matrix, with well-dispersed ZIF-67 particles distributed throughout the porous BC network. Under optimized catalytic conditions (6 mg catalyst, 600 mM NaBH₄, 1 mM nitrobenzene), BCZIF-67 achieved 100% nitrobenzene reduction efficiency within 13 min under UV irradiation (λ = 365 nm), compared to 40% for pristine ZIF-67 under identical conditions. Band-edge estimates and scavenger experiments were consistent with synergistic contributions from photoinduced charge-transfer processes and NaBH₄ derived reducing equivalents. BCZIF-67 maintained high catalytic activity during the first four reuse cycles, retaining a reduction efficiency of 90% in the fourth cycle. The efficiency subsequently decreased to 45% in the fifth cycle with confirmed cobalt leaching, demonstrating the need to improve the long-term stability of the composite. The incorporation of renewable bacterial cellulose offers a sustainable, bio-based strategy for designing ZIF-cellulose catalysts for environmental pollutant remediation.