▎ 摘　　要

Three-dimensional porous nitrogen-doped reduced graphene oxide hydrogels were synthesized by using graphene oxide sheets and hexamethylenetetramine as precursors through a facile one-pot hydrothermal process. Hexamethylenetetramine not only served as a nitrogen dopant and reducing agent in the hydrothermal reaction process, but also played a role as modifier in the formation process of the porous hydrogels. The evolution process and formation mechanism of the hydrogels were analyzed through the investigations by scanning electron microscopy, transmission electron microscopy, Raman and Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. It was found that the three-dimensional porous hydrogels exhibited excellent adsorption capability towards various organic dyes, such as methylene blue, pure blue ink and rhodamine 6G. This result indicated that the developed hydrogels could be a promising adsorbent material in water treatment.