Nitrogen-doped carbon dots modified dibismuth tetraoxide microrods: A direct Z-scheme photocatalyst with excellent visible-light photocatalytic performance

• Published in: Journal of colloid and interface science 2018-12, Vol.531, p.473-482
• Main Authors: Yue, Xiaoyang, Miao, Xuli, Ji, Zhenyuan, Shen, Xiaoping, Zhou, Hu, Kong, Lirong, Zhu, Guoxing, Li, Xiaoyun, Ali Shah, Sayyar
• Format: Article
• Language: English
• Subjects: Dibismuth tetraoxide; Nitrogen-doped carbon dots; Organic pollutants; Z-scheme photocatalyst
• ISSN: 0021-9797; 1095-7103
• DOI: 10.1016/j.jcis.2018.07.086

[Display omitted] In this work, an all solid direct Z-scheme photocatalyst of monoclinic dibismuth tetraoxide microrods/nitrogen-doped carbon dots (m-Bi2O4/NCDs) has been constructed through a simple one-step hydrothermal method. The m-Bi2O4/NCDs photocatalyst exhibits excellent photocatalytic activity for the degradation of methylene orange (MO) and phenol under visible light irradiation. The pollutants of MO (10 mg L−1) and phenol (45 mg L−1) could be efficiently degraded by m-Bi2O4/NCDs within 30 and 120 min, respectively, which is much better than that of the single m-Bi2O4, indicating that the introduction of NCDs into m-Bi2O4 can effectively improve the photocatalytic activity. Moreover, the m-Bi2O4/NCDs photocatalyst possesses a high photocatalytic stability and durability, and its photocatalytic activity did not show obvious decline after four photodegradation cycles. It is found that both O2− and direct h+ oxidation play important roles in the degradation process, and based on the experimental result a direct Z-scheme photocatalytic mechanism is proposed. This study suggests that the as-prepared m-Bi2O4/NCDs composite is a promising photocatalyst for environmental remediation.