Zn3Sb4O6F6 crystallites were synthesized by a pH-regulated hydrothermal synthetic approach, while doping on Zn3Sb4O6F6 by KI was performed by the "incipient wetness impregnation technique." The effect of KI in Zn3Sb4O6F6 is found with the changes in morphology in the doped compound, i.e., needle-shaped particles with respect to the irregular cuboid and granular shaped in the pure compound. Closer inspection of the powder diffraction pattern of doped compounds also reveals the shifting of Braggs' peaks toward a lower angle and the difference in cell parameters compared to the pure compound. Both metal oxyfluoride comprising lone pair elements and their doped compounds have been successfully applied as photocatalysts for methylene blue dye degradation. Knoevenagel condensation reactions were performed using Zn3Sb4O6F6 as the catalyst and confirmed 99% yield even at 60 °C temperature under solvent-free conditions. Both pure and KI-doped compounds were tested against several standard bacterial strains, i.e., Enterobacter sp., Escherichia coli, Staphylococcus sp., Salmonella sp., Bacillus sp., Proteous sp., Pseudomonas sp., and Klebsiella sp. by the "disk diffusion method" and their antimicrobial activities were confirmed.