Enhancing photocatalytic C-C bonds cleavage of lignin β‑O‑4 ketone models by 2D/2D Cu2S/g-C3N4 van der Waals heterojunctions

Selective cleavage of C-C bonds to liberate aromatic monomers from lignin or its analogs under mild conditions remains a significant challenge. In this study, a novel photocatalytic oxidative approach harnessing the Cu2S/g-C3N4 van der Waals heterojunction and specifically targeting the C-C bonds within lignin β-O-4 structures has been explored. The Cu2S/g-C3N4 nanocomposite showed superior sunlight-driven photocatalytic efficacy in disrupting these C-C bonds. A substrate that emulated the β-O-4 linkages of lignin was transformed into aromatic entities with an impressive selectivity of 93.2 % for C-C cleavage. Additionally, the yield of these aromatic compounds peaked at 1346.71 μmol gcat-1.h−1. The performance has been attributed to close electronic interactions observed at the 2D/2D junction, which was substantiated with rigorous characterization. This investigation provides a promising pathway and highlights the potential of photocatalysis in the intricate process of lignin C-C bond disruptions through strategic engineering of the interfaces.