Metastable Porphyrin Assembly Engineered by Spatial Confinement for Amplified Built-In Electric Fields and High-Efficiency Photocatalytic Amino Acid Production

Abstract

Abstract Enhanced charge-separation efficiency is fundamental to advancing organic photocatalytic production of high-value amino acids from biomass feedstocks, which can be promoted by strengthening built-in electric fields (IEF). Yet, current approaches to boost IEF, relying on molecular-scale design, still cannot precisely control π-π stacking architecture, which is crucial for efficient exciton dissociation and charge-carrier extraction. Herein, the metastable Zn porphyrin living supramolecular assembly (LSA) is fabricated via layered double hydroxide. The confinement triggers highly ordered π-π stacking (spacing 3.31 Å), significantly strengthening IEF to 4.52 times that of crystalline Zn-TCPP, achieving a charge-separation efficiency of 51.7%, leading to an enzyme-free photocatalytic alanine generation rate of 103.74 μmol·g–1·h–1. Mechanism studies confirm photogenerated holes oxidize lactic acid to pyruvate, while exposed Zn active sites mediate electron-driven reductive amination. This confinement supramolecular strategy offers a facile route to high-performance porphyrin photocatalysts and advances sustainable sunlight-powered amino acid manufacturing.