Azide-Functionalized Mesoporous Silica SBA-15 for Sustainable Catalysis and Biological Applications

In the present study, azide (─N₃) function was supported on SBA-15 through covalent post-functionalization via a substitution reaction after a chlorination step. Combined XRD and TEM analyses confirm the preservation of SBA-15′s hexagonal structure after functionalization. The successful incorporation of N₃ groups was verified by FTIR (2094 cm⁻¹) and XPS (N1s at 398–400 eV), while TEM/SEM imaging demonstrated maintained porosity. As a heterogeneous catalyst, SBA-15@N₃ demonstrated high catalytic activity for Knoevenagel condensation without requiring the use of a solvent. It offers several advantages, such as light reaction conditions and a simple and environmentally friendly working mode. Knoevenagel products are obtained with high purity without additional purification, with high yields (61%–98%). Moreover, the SBA-15@N₃ catalyst successfully mediated multicomponent chromene synthesis while demonstrating excellent recyclability without activity loss. Tested as an antimicrobial agent, our material shows promising results with inhibition zones of 12 mm (Bacillus sp.), 15 mm (S. aureus), 17 mm (C. albicans), and 50 mm (Ascochyta pisi). These results reveal notable antibacterial activity against Gram-positive bacteria, as well as strong antifungal potential, particularly marked against Ascochyta pisi. To summarize, the results of this work clearly indicate that the SBA-15@N₃ catalyst is economical, environmentally friendly and promising for green chemical reactions, with many potential applications in chemistry and biology.