Nano nickel embedded in N-doped CNTs-supported porous biochar for adsorption-reduction of hexavalent chromium

Danchen Zhu; Jingai Shao; Ziqing Li; Haiping Yang; Shihong Zhang; Hanping Chen

doi:10.1016/j.jhazmat.2021.125693

Nano nickel embedded in N-doped CNTs-supported porous biochar for adsorption-reduction of hexavalent chromium

J Hazard Mater. 2021 Aug 15:416:125693. doi: 10.1016/j.jhazmat.2021.125693. Epub 2021 Mar 20.

Authors

Danchen Zhu¹, Jingai Shao², Ziqing Li³, Haiping Yang¹, Shihong Zhang¹, Hanping Chen⁴

Affiliations

¹ State Key Laboratory of Coal Combustion, School of Power and Energy Engineering, Huazhong University of Science and Technology, 430074 Wuhan, China.
² State Key Laboratory of Coal Combustion, School of Power and Energy Engineering, Huazhong University of Science and Technology, 430074 Wuhan, China; Department of New Energy Science and Engineering, School of Energy and Power Engineering, Huazhong University of Science and Technology, 430074 Wuhan, China. Electronic address: jashao@hust.edu.cn.
³ State Key Laboratory of Coal Combustion, School of Power and Energy Engineering, Huazhong University of Science and Technology, 430074 Wuhan, China; Contemporary Amperex Technology Co., Limited, 352199 Ningde, China.
⁴ State Key Laboratory of Coal Combustion, School of Power and Energy Engineering, Huazhong University of Science and Technology, 430074 Wuhan, China; Department of New Energy Science and Engineering, School of Energy and Power Engineering, Huazhong University of Science and Technology, 430074 Wuhan, China.

PMID: 33819644
DOI: 10.1016/j.jhazmat.2021.125693

Abstract

Nitrogen-doped carbon coated transition metal hybrids for the removal of hazardous hexavalent chromium (Cr(VI)) has attracted increasing attention in wastewater treatment recently. In this study, three-dimensional nano-nickel particles embedded in N-doped carbon nanotubes supported on porous biochar (Ni@N-K-C) were synthesized by a two-stage strategy of KOH activation followed by annealing. The effect of KOH activation treatment on the doping process and Cr(VI) removal properties were investigated. The results indicate that KOH activation can improve the pore parameters and promote subsequent doping of Ni and N and the growth of carbon nanotubes (CNTs). After KOH pretreatment, the specific surface area of Ni@N-K-C increased significantly to 604.62 m²/g. The improved pore structure accelerates the mass diffusion of Cr(VI) ions and provides an available surface for the adsorption and reduction of Cr(VI). Therefore, the Ni@N-K-C obtained at 900 °C showed a high removal capacity for Cr(VI) (824.4 mg/g) and a stronger ability to reduce to Cr(III).

Keywords: Biomass; Carbon nanotubes; Cr(Ⅵ) removal; KOH activation; Porous structure.