Boosting lignin-based photocatalyst with photocorrosion resistance for efficient H2O2 production via hetero-interfacial π-π stacking channels

Abstract

As the most abundant renewable aromatic biopolymer resource on the Earth, lignin has become a cutting-edge research hotspot in clean photocatalysis, thanks to the distinct highest occupied molecular-orbital and lowest unoccupied molecular-orbital energy levels driven by the major β-O-4 linked bonds. However, the complex spatial architecture of functional groups, represented by benzene rings in the 3D intertwined macromolecular chains of lignin, and the challenge of enhancing carrier separation efficiency remain persistent obstacles hindering the development of lignin-based photocatalysts. Herein, a strategy of constructing lignin nanosphere-graphene oxide heterointerfaces (EL-GO) is proposed to comprehensively enhance the efficacy of functional groups and facilitate photoelectron migration modes. The recombination time of light-excited photoelectrons is effectively prolonged by the π-π interactions between the “Donor site” and “Acceptor site” functional regions, along with the directional migration of photoelectrons between EL and GO. The photocatalytic efficiency of H₂O₂ production using EL-GO is significantly enhanced under the protective mechanism of GO. To assess its potential, a prospect estimation of EL-GO in a lake containing various pollutants and metal ions was conducted, simulating real water conditions. This pioneering engineering effort aims to curb excessive consumption of fossil fuels and explore the green applications of lignin, thereby constructing a “carbon-neutral” feedstock system.