Carbonic Anhydrase-Inspired Zn-Single-Atom Nanozyme with High Stability for Enhanced CO₂ Hydration Performance

Area of Science:

• Materials Science
• Catalysis
• Environmental Chemistry

Background:

• Efficient and durable catalysts are crucial for CO2 capture systems.
• Traditional methods using alkaline solvents have high energy costs and safety issues.
• Carbonic anhydrase (CA) is effective but unstable in real-world conditions, and existing mimics lack durability.

Purpose of the Study:

• To develop a robust and efficient catalyst for CO2 hydration.
• To investigate a novel zinc single-atom nanozyme derived from ZIF-8.
• To enhance the catalyst's stability and performance for aqueous CO2 capture.

Main Methods:

• Synthesized ZnNC900, a zinc single-atom nanozyme, via controlled carbonization of zeolitic imidazolate framework (ZIF-8).
• Evaluated catalytic activity using the p-nitrophenyl acetate esterase reaction.
• Functionalized ZnNC900 with amine-terminalized polyethylene glycol to improve hydrophilicity and CO2 affinity.

Main Results:

• ZnNC900 demonstrated high catalytic activity, comparable to CA, due to its single-atomic Zn sites.
• Surface functionalization significantly improved colloidal stability and catalytic performance.
• The modified catalyst exhibited enhanced hydrophilicity and CO2 affinity.

Conclusions:

• ZnNC900 is a durable and efficient catalyst for CO2 hydration.
• The single-atomic Zn sites mimic CA activity effectively.
• Surface modification strategies can further optimize nanozyme performance for aqueous CO2 capture applications.