An efficient and facile method to fabricate a surficial dispersive heterojunction based on the assembly of g-C3N4 nanoparticles was proposed. A p–n nano heterojunction composed of BiOI and g-C3N4 was constructed by simply loading g-C3N4 nanoparticles on flower-like BiOI nanosheets. The structure-dependent optical, electronic and photoelectric properties were investigated, and the structure–property relationship was discussed. The results show that the g-C3N4 nanoparticles are uniformly loaded on the surface of BiOI nanosheets and thus form a p–n heterojunction with an intimate interface. The as-prepared samples exhibit enhanced photocatalytic degradation ability towards MO under visible-light irradiation. With the unique structure and morphology, enhanced visible-light photocatalytic activities are achieved owing to the synergistic effect of light harvesting, high transfer efficiency and enhanced separation efficiency of photo-generated carriers.
Qianhong Shen,Chengyan Wu,Zengyu You,Feilong Huang,Jiansong Sheng,Fang Zhang,Di Cheng,Hui Yang
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.