Lignin Incorporated Supramolecular Copolymerization Yielding g‐C 3 N 4 Nanoarchitectures for Efficient Photocatalytic Hydrogen Evolution

Graphitic carbon nitride (g-C3N4)-based nanostructures are a fast-growing family of metal-free semiconductors that have attracted much attention as hydrogen-evolving photocatalysts. Previous research mostly uses small organic molecules to modify g-C3N4 for improved solar-to-fuel conversion efficiency; however, there are scarce reports on high-efficiency g-C3N4 photocatalysts modified with natural macromolecules. Herein, lignin-modified g-C3N4 nanoarchitectures with an ultrathin layered topography are successfully synthesized. The biomass-modified g-C3N4 photocatalyst obtained through this method delivers a hydrogen-evolving rate of 2235 μmol g−1 h−1, which is 3.5 times higher than that of g-C3N4 calcined from the preorganized cyanuric acid–melamine supramolecular assemblies. On the basis of experimental evidences, the improved hydrogen evolution reaction (HER) performance is attributed to synergistic effects between the ultrathin few-layer 2D nanostructure, extended visible light absorption, and ideal energy band configuration. The biomass-activated g-C3N4 nanostructures prepared via this synthesis route prove suitable for use as cost-effective and efficient photocatalysts for scalable solar hydrogen production.