A novel g-C3N4 nanoparticle@porous g-C3N4 (CNNP@PCN) composite has been successfully fabricated by loading g-C3N4 nanoparticles on the porous g-C3N4 matrix via a simply electrostatic self-assembly method. The composition, morphological structure, optical property, and photocatalytic performance of the composite were evaluated by various measurements, including XRD, SEM, TEM, Zeta potential, DRS, PL, FTIR, and XPS. The results prove that the nanolization of g-C3N4 leads to an apparent blueshift of the absorption edge, and the energy band gap is increased from 2.84 eV of porous g-C3N4 to 3.40 eV of g-C3N4 nanoparticle (Fig. 6). Moreover, the valence band position of the g-C3N4 nanoparticle is about 0.7 eV lower than that of porous g-C3N4. Therefore, the photo-generated holes and electrons in porous g-C3N4 can transfer to the conduction band of g-C3N4 nanoparticle, thereby obtaining higher separation efficiency of photo-generated carriers as well as longer carrier lifetime. Under visible-light irradiation, 6CNNP@PCN exhibits the highest photocatalytic performance (Fig. 8) on MB, which is approximately 3.4 times as that of bulk g-C3N4.

通过简单的静电自组装方法将gC 3 N 4纳米颗粒负载在多孔gC 3 N 4基质上，已成功制备了新型gC 3 N 4纳米颗粒/多孔gC 3 N 4（CNNP @ PCN）复合材料。通过各种测量，包括XRD，SEM，TEM，Zeta电位，DRS，PL，FTIR和XPS，评估了复合材料的组成，形态结构，光学性能和光催化性能。结果证明gC 3 N 4的纳米化导致吸收边缘出现明显的蓝移，并且能带隙从多孔gC 3 N 4的2.84 eV增加到gC 3 N 4纳米颗粒的3.40 eV （图6）。此外，gC 3 N 4纳米粒子的价带位置比多孔gC 3 N 4的价带位置低约0.7eV 。因此，光生空穴和电子在多孔GC 3 Ñ 4可以转移到GC的导带3 Ñ 4纳米颗粒，从而获得更高的光生载流子分离效率以及更长的载流子寿命。在可见光照射下，6CNNP @ PCN在MB上表现出最高的光催化性能（图8），约为整体gC 3 N 4的3.4倍。