Electron cloud modulation in lignin-black phosphorus by alternating electromagnetic fields for enhanced hydrogen...

The inherent photoreactivity of lignin, derived from agricultural and forestry residues, allows it to function as an effective photocatalyst for sustainable green energy production. Alternating electromagnetic fields enhance the efficiency of green photochemical synthesis via periodic high-frequency oscillations. In this study, density functional calculations, molecular dynamics simulations, and electromagnetic absorption characterization were employed to evaluate the H₂O₂ synthesis and photoelectron migration mechanisms of a lignin-black phosphorus composite photocatalyst (ELP) under alternating electromagnetic fields. Through periodic energy injection, the alternating electromagnetic field drives rapid photoelectron migration within the ELP and effectively reduces the secondary recombination rate. Simultaneously, it enhances the periodic migration of the electron cloud within the black phosphorus nanosheets and intensifies the lone pair-π interaction effect, thereby promoting the reconstruction of the internal electronic structure of the ELP, primarily through a dielectric loss mechanism. Further research indicates that ELP catalyzes H₂O₂ synthesis primarily through a two-electron oxygen reduction reaction, establishing a correlation among the electromagnetic loss factor, relaxation time, loss contribution, and photocatalytic H₂O₂ synthesis. This research not only achieves high-value utilization of lignin but also provides a new reference for further clarifying and promoting the coupling mechanisms of multiple physical fields.