Solar-light-driven electrochemical impedance spectroscopy of boron-doped carbon nitride immobilized poly(methyl methacrylate) for advanced photofunctionalization and materials innovation

The development of metal-free photocatalysts with tunable electrochemical properties has attracted widespread attention for next-generation materials innovation. Boron-doped graphitic carbon nitride (B-g-C₃N₄) stands out due to its unique electronic structure and photophysical characteristics; however, its limited processability and difficulty in thin-film fabrication hinder practical implementation. In this work, we report a facile “grafting-to” strategy, where visible-light irradiation is employed to covalently immobilize poly(methyl methacrylate) (PMMA) onto B-g-C₃N₄. The resulting PMMA/B-g-C₃N₄ composite films exhibit enhanced stability, processability, and photo-functionalization, enabling their direct integration into electrochemical impedance spectroscopy (EIS) platforms. The synergistic interaction between PMMA and B-g-C₃N₄ not only improves charge transfer dynamics but also amplifies optical response, representing a significant step toward functional thin-film architectures. This study provides a promising route for advancing boron-doped carbon nitride in electrochemical and optoelectronic applications, paving the way for sustainable, high-performance materials development.