Electrochemical processes in neutral electrolytes are inherently constrained by limited proton availability and sluggish charge-transfer kinetics, making interface engineering a critical strategy for performance enhancement. To address these challenges, this study demonstrates a tailored interfacial approach to regulate charge transfer and electrolyte accessibility by functionalizing the Ti2AlC MAX phase with polydopamine, followed by carbonization to engineer nitrogen-doped carbon/Ti2AlC MAX phase interfaces. The surface modification results in a heteroatom-rich environment with abundant active sites and enhanced surface polarity, as confirmed by X-ray photoelectron spectroscopy. The electrochemical behavior was systematically evaluated to deconvolve the relationship between surface modification and electrochemical performance. Electrochemical impedance spectroscopy reveals a significant reduction in the charge-transfer resistance. The synergistic interaction between the N-doped carbon and the Ti2AlC MAX phase shows an approximately 65% reduction in the Tafel slope, indicating substantially improved hydrogen evolution kinetics and also enhanced specific capacitance compared to the pristine Ti2AlC MAX phase. These results highlight the crucial role of surface functionalization in tailoring interfaces that are effective to overcome kinetic barriers in neutral media, providing a methodological framework for designing advanced electrode interfaces in sustainable electrochemical systems.
Aparna et al. (2026) studied this question.