Facile and green preparation of solid carbon nanoonions via catalytic co-pyrolysis of lignin and polyethylene and their adsorption capability towards Cu(ii)

• Published in: RSC advances 2022-02, Vol.12 (8), p.5042-5052
• Main Authors: Wu, Xiankun, Guo, Ting, Chen, Ziyan, Wang, Zhanghong, Qin, Kun, Wang, Zhikang, Ao, Ziqiang, Yang, Cheng, Shen, Dekui, Wu, Chunfei
• Format: Article
• Language: English
• Subjects: Adsorption; Aqueous solutions; Carbon; Catalysts; Chemistry; Endothermic reactions; Functional groups; Lignin; Nanomaterials; Polyethylene; Polyethylenes; Pyrolysis; Size distribution; Surface chemistry
• ISSN: 2046-2069; 2046-2069
• DOI: 10.1039/d1ra06761c

Carbon nanomaterials, such as carbon nanoonions (CNOs), possess promising applications in various fields. There are urgent demands to synthesize carbon nanomaterials from a green and renewable carbon source. In this study, solid CNOs with relatively uniform size distribution (with diameters of about 30-50 nm), abundant structure defects and oxygen-containing surface functional groups (such as -OH and -COOH) are developed from co-pyrolysis of lignin (LG) and polyethylene (PE) in the presence of Ni-based catalysts. The type of catalyst, the concentration of catalyst and catalytic co-pyrolysis temperature play important roles in the morphologies and properties of CNOs as confirmed by TEM and SEM. Furthermore, the produced CNOs can act as a low-cost and highly-efficient adsorbent to remove Cu(ii) from aqueous solution according to a homogeneous monolayer, chemical action-dominated, endothermic and spontaneous process. The theoretical maximum adsorption capacity of CNOs calculated from the Langmuir model is 100.00 mg g . Surface deposition, complexation, π electron-cation interaction and electrostatic interaction are responsible for the adsorption of Cu(ii) using the prepared CNOs.