Gel-like carbon dots: A high-performance future photocatalyst

JOURNAL OF COLLOID AND INTERFACE SCIENCE

卷:599

Article

Zhou, Yiqun¹  ElMetwally, Ahmed E.^1,2  Chen, Jiuyan¹  Shi, Wenquan³  Cilingir, Emel K.¹  Walters, Brian⁴  Mintz, Keenan J.¹  Martin, Christian¹  Ferreira, Braulio C. L. B.¹  Zhang, Wei¹  Hettiarachchi, Sajini D.¹  Serafim, Leonardo F.¹  Blackwelder, Patricia L.^1,5  Wikramanayake, Athula H.⁴  Peng, Zhili³  Leblanc, Roger M.¹ 

[1] Univ Miami, Dept Chem, Coral Gables, FL 33146 USA

[2] Egyptian Petr Res Inst, Petrochem Dept, Cairo 11727, Egypt

[3] Yunnan Univ, Natl Ctr Int Res Photoelect & Energy Mat, Sch Mat & Energy, Kunming 650091, Yunnan, Peoples R China

[4] Univ Miami, Dept Biol, Coral Gables, FL 33146 USA

[5] Univ Miami, MGS RSMAS, Key Biscayne, FL 33149 USA

关键词: Photocatalysis;    Carbon dots;    Wastewater treatment;    Degradation;    Mineralization;   

DOI  :  10.1016/j.jcis.2021.04.121

来源: Elsevier

【 摘 要 】

To protect water resources, halt waterborne diseases, and prevent future water crises, photocatalytic degradation of water pollutants arouse worldwide interest. However, considering the low degradation efficiency and risk of secondary pollution displayed by most metal-based photocatalysts, highly efficient and environmentally friendly photocatalysts with appropriate band gap, such as carbon dots (CDs), are in urgent demand. In this study, the photocatalytic activity of gel-like CDs (G-CDs) was studied using diverse water pollution models for photocatalytic degradation. The degradation rate constants demonstrated a remarkably enhanced photocatalytic activity of G-CDs compared with most known CD species and comparability to graphitic carbon nitride (g-C3N4). In addition, the rate constant was further improved by 1.4 times through the embedment of g-C3N4 in G-CDs to obtain CD-C3N4. Significantly, the rate constant was also higher than that of g-C3N4 alone, revealing a synergistic effect. Moreover, the use of diverse radical scavengers suggested that the main contributors to the photocatalytic degradation with G-CDs alone were superoxide radicals (O-2(center dot)) and holes that were, however, substituted by O-2(center dot) and hydroxyl radicals (center dot OH) due to the addition of g-C3N4. Furthermore, the photocatalytic stabilities of G-CDs and CD-C3N4 turned out to be excellent after four cycles of dye degradation were performed continuously. Eventually, the nontoxicity and environmental friendliness of G-CDs and CD-C3N4 were displayed with sea urchin cytotoxicity tests. Hence, through various characterizations, photocatalytic degradation and cytotoxicity tests, G-CDs proved to be an environmentally friendly and highly efficient future photocatalyst. (C) 2021 Elsevier Inc. All rights reserved.

【 授权许可】

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