Synthesis of Z-Scheme heterojunction ZnNb2O6/g-C3N4 nanocomposite as a high efficient photo-catalyst for the degradation of 2, 4-DCP under simulated sunlight. (October 2020)

• Record Type: Journal Article
• Authors: Gu, Xinyue; Mei, Jie; Lai, Jiahao; Lv, Siying; Yang, Jing; Cui, Shihai; Chen, Sen
• Is Part Of: Materials research bulletin. Volume 130(2020)
• Publication Date: 2020-10
• Subjects: ZnNb2O6/g-C3N4 nanocomposite -- 2, 4-dichlorophenol -- Photocatalytic degradation -- Z-Scheme heterojunction -- Degradation mechanism; Materials -- Periodicals; Crystal growth -- Periodicals; Matériaux -- Périodiques; Cristaux -- Croissance -- Périodiques; Crystal growth; Materials; Periodicals; 620.11
• DOI: 10.1016/j.materresbull.2020.110939
• Languages: English
• ISSNs: 0025-5408

Abstract

Graphical abstract: Highlights: A novel ZnNb2 O6 /g-C3 N4 material has been prepared by calcination-hydrothermal method. About 95.7% 2, 4-DCP can be degraded under 180 min simulated sunlight irradiation. The photocatalytic mechanism was discussed through active species and band structure. The photocatalytic mechanism of Z-scheme heterojunction was proposed. The h + and ·O2 − played the major roles on 2, 4-DCP degradation. Abstract: In view of the deterioration of the environment and the shortage of resources, it is necessary to develop efficient photocatalysts for the degradation of organic pollutants. Herein, a novel and environmentally friendly ZnNb2 O6 /g-C3 N4 heterojunction nanocomposite was synthesized by calcination-hydrothermal method successfully. The chemical and physical capabilities of the material were characterized by various kinds of analytical instruments. Compared with ZnNb2 O6 and g-C3 N4, ZnNb2 O6 /g-C3 N4 showed the strongest photocatalytic activity. The nanomaterial was used in the removal of the pollutant 2, 4-DCP. The effects of degradation conditions were discussed including component ratio, material dosage, initial analyte concentration, pH and salinity. After 180 min' simulated sunlight illumination, the removal efficiency of 2, 4-DCP (10 mg/L) reached 95.7% under the optimum condition. Furthermore, the possible photocatalytic mechanisms were discussed according to four aspects: (i) The conformation of the active species; (ii) The calculation of valence and conduction band; (iii) The analysis Z-scheme heterojunction mechanism; (iv) The speculation of feasible photocatalytic paths. In conclusion, the ZnNb2 O6 /g-C3 N4 (ZC-7) nanocomposite has the least recombination rate of electron-hole pairs and the highest photocatalytic efficiency.