Ti₃C₂ MXene Quantum Dots/Lignin Interface Enables Field-Driven H₂O₂ Photosynthesis via Electron-Molecular Dynamics

The high-value utilization of lignin is regarded as pivotal for waste biomass valorization and sustainable chemical synthesis. However, the mechanistic understanding of its photocatalytic processes at the molecular scale under coupled exogenous physical fields is currently perceived to be limited. In this work, through the integration of advanced spectral characterization and multi-scale theoretical simulations, it is demonstrated that oxygen activation and photoelectron shuttling efficiency are significantly enhanced by the composite photocatalyst consisting of lignin nanoparticles and Ti₃C₂ Mxene quantum dots under alternating electromagnetic fields. The dynamic structural rotation and photoelectron transitions within lignin molecules are synergistically regulated by the alternating electromagnetic field and the Ti₃C₂ Mxene quantum dots. Specifically, a 3.8 times performance enhancement over pristine lignin is achieved by the system, as H₂O₂ synthesis is facilitated via a long-lived triplet pathway for oxygen activation and reduction. New insights into the interfacial dynamic response mechanisms of photocatalysis under alternating electromagnetic fields are provided by these findings. The bifunctional mechanism, characterized by its combination of spatial electron separation and structural dynamic response, is identified as a key driver for high-value chemical synthesis catalyzed by biomass-based photocatalysts.