Titanium carbide-based nanocomposite: A promising reinforcing material for enzymatic CO2 conversion

Abstract

Enzymatic conversion of CO2 to formate is a highly significant pathway for CO2 utilization, but current level of conversion efficiency remains unsatisfactory due to low solubility of CO2 under mild conditions. CO2-philic materials can significantly augment the reaction by raising local concentration of substrate. Herein, the intercalated Ti3C2Tx, nano-silica (SiO2) and carbon nitride (CN) with abundant CO2 adsorption sites were introduced to fabricate Ti3C2Tx based nanocomposites, Ti3C2Tx/SiO2/CN (TSCN), for the first time. As the controls, binary composites including Ti3C2Tx/SiO2 (TS), Ti3C2Tx/CN (TCN) and SiO2/CN (SCN) were also studied. For each kind of material, the composition, structure, morphology, and application performance in the enzymatic CO2 conversion were characterized and influencing factors were investigated. Among these composites, TSCN exhibited the best application performance and the enzyme reaction was accelerated up to 23.9 times that of the blank system. The value could reach as high as 35.3 after polyethyleneimine (PEI) modification. Following that, PEI modified composites were used as carrier of formate dehydrogenase (FDH) and apparent specific activity was up to 2.8 times that of free enzyme, which could retain 88.2% of the initial value after 10 cycles associated with the structural integrity. This work provides new impetus to CO2 capture and conversion in a clean and mild way that shows bright application prospects.