Ultrathin Crystalline Carbon Nitride Nanosheets for Highly Efficient Photocatalytic Pollutant Removal and Hydrogen Production

We present a facile bottom-up strategy to prepare crystallinepolymericcarbon nitride (CCN) with ultrathin 2D nanosheet structures, whichinvolves supramolecular self-assembly into crystalline rodlike intermediatesand subsequent thermal-induced exfoliation and polycondensation. Undervisible light irradiation, CCN can efficiently remove various high-concentrationorganic pollutants (50 mg L-1) and synergisticallyremove organic pollutants and heavy metal ions. The removal ratesof all organic pollutants including antibiotics and dyes exceed 95%within 40 min, outperforming previously reported photocatalysts. Moreover,it also exhibits outstanding photocatalytic performance in the water-splittingreaction with a H-2 evolution rate of 11.5 mmol g(-1) h(-1). The highly boosted activity of CCN can beattributed to the significantly improved charge separation, the increasedaccessible active sites, as well as the enhanced visible light absorption,benefiting from its high crystallinity and ultrathin 2D nanosheetstructure. This work presents a feasible strategy for the preparationof crystalline carbon nitride nanosheets toward energy and environmentalapplications.

Automated summary

We propose a simple bottom-up strategy for preparing crystalline polymeric carbon nitride (CCN) with ultrathin 2D nanosheet structures. CCN can efficiently remove various high-concentration organic pollutants and heavy metal ions under visible light irradiation. It also exhibits outstanding photocatalytic performance in the water-splitting reaction. The highly boosted activity of CCN is attributed to the significantly improved charge separation, increased active sites, and enhanced visible light absorption.