Pyrimidine-modified g-C3N4 nanosheets for enhanced photocatalytic H2 evolution

Designing visible-light-driven, high-efficiency, robust photocatalysts with practical potential is an important direction in the photocatalysis field. Herein, pyrimidine-modified g-C3N4 (Pym-CN) photocatalysts with curled nanosheet morphology were prepared through a facile supramolecular assembly method. Pyrimidine has only two N atoms, thus leading to the deficiency formation in the supramolecular assembly of cyanuric acid with melamine. Upon calcination, the deficiency decreases the polycondensation degree of g-C3N4, thereby further affecting its morphology and optoelectronic property. The pyrimidine modification can enhance the absorption capacity toward visible light and facilitates the separation of photo-generated carriers. By changing the adding amount of pyrimidine, the optimal Pym-CN photocatalyst exhibits a H-2 evolution rate of 1046 mu mol g(-1) under visible light, which is almost 30 times higher than that of pristine g-C3N4. This work may afford a novel approach to modifying organic polymer semiconductor photocatalysts with small organic molecules of nonplanar structure.