CARBONLETT, vol. 22, no. 1, pp.60-69, 2017

DOI: http://dx.doi.org/10.5714/CL.

Nitrogen-doped carbon nanosheets from polyurethane foams and removal of Cr(VI)

Jiaqi Duan^1,2, Baohua Zhang¹, Huailin Fan^2,3, Wenzhong Shen² and Shijie Qu^2,♠

Affiliation: ¹Department of Chemical Engineering, School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China
²State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001, China
³University of Chinese Academy of Sciences, Beijing 100049, China

Abstract: Nitrogen-doped carbon nanosheets with a developed porous structure were prepared from polyurethane foams by hydrothermal carbonization following ZnCl₂ chemical activation. Scanning electron microscopy, thermogravimetric analysis, Fourier transform infrared spectroscopy, solid state ¹³C nuclear magnetic resonance (NMR) spectra and X-ray photoelectron spectroscopy were used to characterize the nitrogen-doped carbon nanosheet structure and composition. The removal of Cr(VI) by the N-doped carbon nanosheets was investigated. The results showed that the maximum removal capacity for chromium of 188 mg/g was found at pH=2.0 with PHC-Z-3. pH had an important effect on Cr(VI) removal and the optimal pH was 2.0. Moreover, amino groups and carboxyl groups in the nitrogen-doped carbon nanosheet played important roles in Cr(VI) removal, and promoted the reduction of Cr(VI) to Cr(III).

Keyword: polyurethane forms, nitrogen-doped carbon nanosheet, Cr(VI) removal