Abstract
Photocatalytic cleavage of C-C bond in lignin under mild conditions transforms solar energy into high value-added aromatic compounds. However, the limited understanding of cleavage mechanisms and the catalyst structure-performance relation obstruct the rational design of efficient photocatalysts. Reported herein is the construction of porous carbon nitride (C3N4) with carbon vacancies as heterogeneous photocatalysts via a sequential self-assembly and diol-induced thermal exfoliation. In the photocatalytic cleavage of β-O-4 ether bonds, carbon vacancies in C3N4 can serve as the trapping site to suppress the recombination of photogenerated charge, and endow the C3N4 with high level of N and thus make it easier for the oxidation of Cn-H, contributing to the enhancement of performance. Furthermore, the experimental result and in situ ATR-SEIRAS spectra unveil that O2 could facilitate the cleavage of C-C bond but is not indispensable in this process, which brings new fundamental understanding of β-O-4 bonds cleavage.
NSTL