Confined synthesis of g-C3N4 modified porous carbons for efficient removal of Cd ions

Yi Sun; Yijing Li; Xiaoyue Zhang; Junling Duan; Jing Dong; Ju Peng; Jianchao Sun; Shiyun Ai; Juying Hou

doi:10.1016/j.scitotenv.2023.164167

Confined synthesis of g-C₃N₄ modified porous carbons for efficient removal of Cd ions

Sci Total Environ. 2023 Aug 25:888:164167. doi: 10.1016/j.scitotenv.2023.164167. Epub 2023 May 16.

Authors

Yi Sun¹, Yijing Li², Xiaoyue Zhang², Junling Duan², Jing Dong², Ju Peng³, Jianchao Sun⁴, Shiyun Ai⁵, Juying Hou⁶

Affiliations

¹ College of Chemistry and Material Science, Shandong Agricultural University, Taian 271018, PR China; Key Laboratory of Agricultural Film Application of Ministry of Agriculture and Rural Affairs, Taian 271018, PR China.
² College of Chemistry and Material Science, Shandong Agricultural University, Taian 271018, PR China.
³ Key Laboratory of Marine Eco-Environmental Science and Technology, Marine Bioresource and Environment Research Center, First Institute of Oceanography, Ministry of Natural Resources, Qingdao 266061, PR China.
⁴ School of Environment and Material Engineering, Yantai University, Yantai 264005, PR China.
⁵ College of Chemistry and Material Science, Shandong Agricultural University, Taian 271018, PR China. Electronic address: ashy@sdau.edu.cn.
⁶ College of Chemistry and Material Science, Shandong Agricultural University, Taian 271018, PR China; Key Laboratory of Agricultural Film Application of Ministry of Agriculture and Rural Affairs, Taian 271018, PR China. Electronic address: juyinghou@sdau.edu.cn.

PMID: 37201852
DOI: 10.1016/j.scitotenv.2023.164167

Abstract

Carbon nitride (C₃N₄) nanosheets have excellent adsorption capacity, environmental friendliness, and high stability for heavy metal removal. However, its application in Cd-polluted soil is difficult as aggregation induces the specific surface area to substantially decrease. In this study, a series of C₃N₄ nanosheet-modified porous carbons (C₃N₄/PC-X) were prepared by a simple one-step calcination of mixed aerogels with different mass ratios (X) of carboxymethyl cellulose (CMC) and melamine. These were based on the confined effect of the CMC aerogel, whose 3D confined region controls the C₃N₄ morphology and prevents the aggregation of nanosheets. The resulting C₃N₄/PC-4 exhibited a porous structure with interpenetrating C₃N₄ nanosheets and carbon rods. C₃N₄/PC-4 was characterized by SEM, elemental analysis, XRD, FTIR and XPS, and the existence of C₃N₄ nanosheets was confirmed. Compared with that of unmodified porous carbons, the adsorption capacity of C₃N₄/PC-4 for Cd ions increased 3.97 times, up to 273.1 mg/g. The adsorption kinetics and adsorption isotherm analyses showed that the adsorption properties were in agreement with the quasi-second-order and Freundlich adsorption models. Moreover, the material had a good passivation effect on the Cd ions in the soil. The confined synthesis of aerogels could be extended to the preparation of other nanostructures.

Keywords: Aerogel; C(3)N(4); Cadmium; Carboxymethyl cellulose; Confined synthesis; Porous carbons.