Efficient photoreforming of lignocellulose into H2 and photocatalytic CO2 reduction via in-plane surface dyadic heterostructure of porous polymeric carbon nitride

Photoreforming of lignocellulose for sustainable H-2 generation appears to be a good option at the time that biomass wastes are being degraded. Recently, polymeric carbon nitride (PCN) has emerged as a promising alternative for the photorefoming reaction, however, its photocatalytic performance is largely limited by its severe recombination of charge carriers. Here, we developed an approach, for the first time, to construct a curly-like carbon nitride nanosheets with the formation of in-plane surface dyadic heterostructure for steering the charge transfer and optimizing the electronic band structure. This PCN material shows superior photoreforming H-2 evolved activity of 122.77 mu molh(-1) (i.e. 4092 mu molh(-1)g(-1)) from the aqueous lignocellulose solution (using Pt as cocatalyst), 15.6 folds of pristine PCN under visible light irradiation, together with an apparent quantum efficiency (AQE) of 7.87% (lambda = 420 nm). It enables the visible-light-driven conversion of several kinds of lignocellulose including the monosaccharides, disaccharides, hemicellulose, and cellulose. Additionally, when used as a photocatalyst for water splitting, it achieves a remarkable H-2 production rate of 22043 mu molh(-1)g(-1) (similar to 56.0 folds' increases than pristine PCN) with a superior high AQE of 41.2%, as well as a high CO reduction rate of 56.3 mu molh(-1) from the photocatalytic CO2 conversion, 24.5 times than pristine PCN. (C) 2020 Published by Elsevier Ltd.