Amino Acid-Based Block Copolymer Templates-Dependent Enhancement of Physicochemical and Electrochemical Characteristics of Mesoporous Carbons

Abstract

Amino acid？based block copolymers (BCPs) have distinct features such as secondary structure formation, chirality, amphoteric nature, non-toxicity, and biodegradability, setting them apart from other BCPs. This suggests that amino acid？based BCPs may exhibit unique self-assembly behaviors. Despite these advantages, they have not yet been utilized as templates for mesoporous carbons (MCs) synthesis. Here, we investigate, for the first time, the effect of hydrophobicity of two different poly(ethylene glycol) (PEG) conjugated amino acid？based BCP templates (PEG-poly(β-benzyl-l-aspartate) (PEG-PBLA) and PEG-poly(γ-benzyl-l-glutamate) (PEG-PBLG)) on the construction of MC materials and also their physicochemical and electrochemical characteristics. MCs produced using PEG-PBLA and PEG-PBLG as templates are labeled CPBLA and CPBLG, respectively. Utilizing amino acid？based BCP systems enabled achieving MC materials with nearly 1 at% nitrogen doping without external nitrogen dopants. Physicochemical analysis showed CPBLA had a smaller particle size, higher specific surface area, pore size, and hydrophilicity due to increased oxygen and nitrogen contents, as well as a higher defective structure than CPBLG. The higher hydrophilicity of PEG-PBLA led to the formation of CPBLA MC particles with smaller size and higher specific surface area of 602 m2g？1 and pore size of 7.8？nm. Cyclic voltammetry demonstrated that CPBLA had superior charge-storing capacity (specific capacitance of 147？F？g？1 at 1 mv s？1) than CPBLG, attributed to its better physicochemical properties. These promising findings suggest that amino acid？based BCP systems can serve not only as templates but also as carbon and nitrogen sources, offering potential for high-performance electrochemical energy storage devices.