Effect of high-voltage discharge non-thermal plasma on g-C3N4 in a plasma-photocatalyst system

• Published in: Chinese journal of catalysis Vol. 39; no. 10; pp. 1672 - 1682
• Main Authors: Wang, Xiaoping, Chen, Yixia, Fu, Min, Chen, Zihan, Huang, Qiulin
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.10.2018
• Subjects: Chemical characteristic; g-C3N4; Non-thermal plasma; Photocatalytic activity; Physical structure; g-C3N4; Photocatalytic activity; Non-thermal plasma; Physical structure; Chemical characteristic
• ISSN: 1872-2067; 1872-2067
• DOI: 10.1016/S1872-2067(18)63115-8

The synergistic effect of high voltage discharge non-thermal plasma (NTP) and photocatalysts on contaminant removal has repeatedly confirmed by plenty of researches. Most previous plasma-photocatalyst synergistic systems focused on the utilization of the ultraviolet light but ignored the visible light generated by high voltage discharge. Graphitic carbon nitride (g-C3N4), a metal-free semiconductor that exhibits high chemical stability, can utilize both the ultraviolet and visible light from high voltage discharge. However, the synergistic system of NTP and g-C3N4 has been researched little. In this paper, the effect of NTP generated by dielectric barrier discharge (DBD) on g-C3N4 is studied by comparing the photocatalytic activities, the surface physical structure and the surface chemical characteristics of pristine and plasma treated g-C3N4. Experimental results indicate that the DBD plasma can change the physical structure and the chemical characteristics and to further affect the photocatalytic activity of g-C3N4. The effect of NTP on g-C3N4 is associated with the discharge intensity and the discharge time. For a long time scale, the effect of NTP on g-C3N4 photocatalysts presents a periodic change trend. The periodic oxidation and exfoliation on g-C3N4 photocatalysts under long-time DBD treatment is reported. Further, chemical and physical changes on g-C3N4 influence the photocatalytical activities.