Fabrication of polyphenol-etched amino acid-modified ZIF-8 and their carbonic anhydrase-like catalytic activity

Carbonic anhydrase mimics have recently emerged as promising alternative catalysts for industrial CO 2 capture and utilization. Up to now, many strategies have been developed to design and prepare nanostructures with excellent carbonic anhydrase-like catalytic activity. Herein, two kinds of polyphenol molecules (tannic acid (TA) and gallic acid (GA)) were used to etch amino acid (valine (Val) and leucine (Leu)) modified ZIF-8 (AA-ZIF-8) for fabricating carbonic anhydrase mimics. The TA-treated AA-ZIF-8 (Val-ZIF-8/TA and Leu-ZIF-8/TA) possess hollow nanostructure while the GA-treated AA-ZIF-8 (Val-ZIF-8/GA and Leu-ZIF-8/GA) are decomposed into smaller nanoparticles . Zn-polyphenol coordination interaction and protons released by polyphenols are considered to be the driving force for the etching of AA-ZIF-8. Using hydrolysis of p-nitrophenyl acetate (p-NPA) as the model reaction, the carbonic anhydrase-like activity of AA-ZIF-8/polyphenol nanoparticles were evaluated and the results indicated their excellent catalytic activity. Moreover, after using AA-ZIF-8/polyphenol as catalysts, the CO 2 hydration efficiency could also be enhanced. This work provides a new approach for developing carbonic anhydrase mimics, which could help for designing of materials for industrial CO 2 capture.