Facile one-pot synthesis of bimodal mesoporous carbon nitride and its function as a lipase immobilization support

Bimodal mesoporous carbon nitride is synthesized using Triton X-100 as a template and melamine and glutaraldehyde as precursors through polymerization and carbonization. The structures and surface chemical properties of carbon nitrides are characterized and compared by nitrogen adsorption isotherms, TG, FT-IR spectra and SEM images. The results show that the mesopore sizes in the carbon nitride are centered at 3.8 nm and 10–40 nm. The pyrolysis and decomposition of the polymer to form the condensation cross-linking ring structures takes place at 350–700 °C. The nitrogen atom in the carbon nitride exists in C–N and N–H states. As a Candida rugosalipase immobilization support, the mesoporous carbon nitride displays a higher amount of immobilization and improves the thermal stability of Candida rugosalipase, which still displays higher catalytic activity after 4 runs.