Incorporating a novel metal-free interlayer into g-C3N4 framework for efficiency enhanced photocatalytic H2 evolution activity

•The novel nonmetal interlayer incorporated into the g-C3N4 framework is successfully fabricated.•It exhibits the improvement of photocatalytic activity in H2 evolution.•The introduction of nonmetal interlayer effectively adjusts band gap and increases the separation efficiency of charge carriers.•A possible photocatalytic mechanism is proposed.

Graphitic carbon nitride (g-C3N4) has become a research hotspot recently owing to its unique advantage and wide application in the field of photocatalysis. However, the photocatalytic activity of the traditional two-dimensional g-C3N4 material is unsatisfactory owing to the relatively narrow visible light responsive region and high recombination probability of photogenerated charge carriers. Here, the novel nonmetal interlayer incorporated into the g-C3N4 framework is successfully fabricated by thermal polymerization of the β-cyclodextrin (β-CD) and melamine as precursors, which significantly enhances the photocatalytic performance for H2 evolution than that from g-C3N4. The corresponding characterization methods demonstrate that the interlayer is composed of oxygen-contained graphitized carbon as well as the enhanced photocatalytic activity originates from the narrowed band gap, negative-shifted conduction band position and efficient charge transfer caused by this metal-free interlayer incorporation. It not only results in the form of the COC bonding between the interlayer and g-C3N4 but also can bridge the interlayer and extend the π-conjugated system, which facilitate the charge-carrier migration and separation. The current work could provide new insights for constructing other high performance, low-cost and metal-free photocatalyst for H2 evolution.

Graphical abstractA novel metal-free intercalated g-C3N4 is successfully fabricated by thermal polymerization of the β-cyclodextrin and melamine as precursors, which significantly enhances the photocatalytic performance for H2 evolution.Download high-res image (163KB)Download full-size image