Thio-groups decorated covalent triazine frameworks for selective mercury removal

Zhenlian Yang; Yangyi Gu; Baoling Yuan; Yuanmeng Tian; Jin Shang; Daniel C W Tsang; Mingxian Liu; Lihua Gan; Shun Mao; Liangchun Li

doi:10.1016/j.jhazmat.2020.123702

Thio-groups decorated covalent triazine frameworks for selective mercury removal

J Hazard Mater. 2021 Feb 5:403:123702. doi: 10.1016/j.jhazmat.2020.123702. Epub 2020 Aug 15.

Authors

Zhenlian Yang¹, Yangyi Gu¹, Baoling Yuan¹, Yuanmeng Tian², Jin Shang³, Daniel C W Tsang⁴, Mingxian Liu¹, Lihua Gan¹, Shun Mao⁵, Liangchun Li⁶

Affiliations

¹ Shanghai Key Lab of Chemical Assessment and Sustainability, School of Chemical Science and Engineering, Tongji University, Shanghai, 200092, PR China.
² Shanghai Key Lab of Chemical Assessment and Sustainability, School of Chemical Science and Engineering, Tongji University, Shanghai, 200092, PR China; School of Energy and Environment, City University of Hong Kong, Tat Chee Avenue, Kowloon, 999077, Hong Kong, China.
³ School of Energy and Environment, City University of Hong Kong, Tat Chee Avenue, Kowloon, 999077, Hong Kong, China.
⁴ Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China. Electronic address: dan.tsang@polyu.edu.hk.
⁵ State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, PR China.
⁶ Shanghai Key Lab of Chemical Assessment and Sustainability, School of Chemical Science and Engineering, Tongji University, Shanghai, 200092, PR China. Electronic address: lilc@tongji.edu.cn.

PMID: 33264889
DOI: 10.1016/j.jhazmat.2020.123702

Abstract

Covalent triazine frameworks (CTFs) as a kind of covalent organic framework (COF) materials show great potential for practical application by virtue of their high stability and facile large-scale synthesis. In this work, we developed three CTFs (MSCTF-1, MSCTF-2, and xSCTF-2) of different pore size decorated with S-groups using different functionalization methods for achieving selective Hg²⁺ removal from aqueous solutions. The material structures were comprehensively studied by gas adsorption, IR and XPS, etc. Among them, the MSCTF-2 with 24.45% S content showed the highest Hg²⁺ adsorption capacity of 840.5 mg g^‒1, while MSCTF-1 exhibiting much larger distribution coefficient of 1.67 × 10⁸ mL g^‒1 renders an exceptionally high efficiency for reducing the concentration of Hg²⁺ contaminated water to less than 0.03 μg L^‒1. Moreover, the MSCTFs show distinct features of: (i) high selectivity toward Hg²⁺ over various transition metal ions; (ii) high stability over a wide pH range from pH 1 to 12; and (iii) good recyclability with 94% of Hg²⁺ removal over five consecutive cycles. The Hg²⁺ adsorption on functionalized CTFs followed pseudo-second-order kinetics and Langmuir isotherm. Our results revealed the material structure-performance relationship that the adsorption capacities depend on the binding site density whereas the distribution coefficient is essential to the removal efficiency.

Keywords: Advanced adsorbents; Covalent triazine framework; High selectivity/recyclability; Mercury adsorption; Sulfur-functionalized.

Publication types

Research Support, Non-U.S. Gov't