Microelectric Field Engineering in Carboxyl-Rich Polymeric Photocatalysts for Enhanced Exciton Dissociation and pH-Responsive Environmental Photocatalysis

Abstract Polymeric photocatalysts demonstrate significant potential for environmental remediation and energy conversion due to their tailorable structures and multifunctional integration. However, their practical applications are severely limited by intrinsic bottlenecks, especially the sluggish exciton dissociation and rigorous synthetic conditions. Herein, a strategy based on microelectric field manipulation is proposed, involving in situ polymerization of photosensitizers into carboxyl-rich polymeric matrices. The target photocatalyst TVMN is facilely synthesized via the self-stabilized precipitation (2SP) polymerization of photosensitizers and maleic anhydride (MAH), followed by the alkylamine-induced ring-opening reaction of MAH to introduce carboxyl groups. These carboxyl groups construct local microelectric fields around photosensitizers, significantly promoting exciton dissociation and charge transfer. Consequently, TVMN achieves a remarkably reduced exciton binding energy of 44.48 meV, enabling efficient generation of reactive oxygen species, including •OH and •O2–. Moreover, carboxyl modification endows TVMN with enhanced hydrophilicity, which strengthens the interfacial interaction between the photocatalyst and water, as well as endows the photocatalyst with pH-responsive recoverability. This work offers a paradigm for enhancing exciton dissociation via microelectric field engineering and expands its application in environmental photocatalysis.