Highly selective capacitive deionization of copper ions in FeS2@N, S co-doped carbon electrode from wastewater

Nitrogen-doped carbon nanotube encapsulated Fe7S8 nanoparticles for the high-efficiency and selective removal of Pb2+ by pseudocapacitive coupling

“…The structural composition of the CDI device followed our previous work. 20 During the HCDI cell assembly, the Fe 3 C@NCNT or Fe 7 S 8 @NCNT electrode was used as a cathode and an activated carbon electrode was utilized as an anode. The electrodes were fabricated as follows: 80 wt% active ingredients, 10 wt% Ketjen black, and 10 wt% PVDF were mixed with NMP.…”

“…[25][26][27] Our previous approach was reported for solving the above issues on FeS 2 in the removal of Cu 2+ , in which nanosized FeS 2 particles composited with an N, S co-doped carbon matrix were utilized as a cathode, and achieved a high-efficiency electrosorption capacity of 508.5 mg g −1 towards Cu 2+ ions. 20 The deep Faradaic redox reaction of Fe 2+ /Fe 3+ dominated the removal capacity of Cu 2+ , indicating that the pseudocapacitance of FeS x has great potential for seizing Pb 2+ ions.…”

“…Although developing a carbon–FeS 2 composite could efficiently relieve the volumetric variation and structural distortion, the aggregation and comminution of FeS 2 nanoparticles on a carbon matrix still takes place during adsorption–desorption cycles, leading to a deterioration in the performance of electrodes in our previous work. 20 To overcome this issue, the design concept of encapsulating Fe 7 S 8 nanoparticles in one-dimensional (1D) N-doped carbon nanotubes (NCNT) covalently bonded onto a 3D carbon matrix to construct a 3D hierarchical configuration is very much expected to provide prominent electrosorption performance towards Pb 2+ ions.…”

“…17 At the same time, FeS x has aroused a lot of interest for metal-ion batteries, supercapacitors, and capacitive deionization, demonstrating its superior electrochemical performance. [18][19][20] Several common drawbacks, however, have blocked the real application of FeS x as an electrode, such as low electroconductivity, depressed ion diffusion kinetics, and irreversible volumetric expansion over the period of the electrochemical reaction. 21 To overcome these issues, the following tactics can be used: (i) the particle size of FeS x can be nanosized as much as possible, which could greatly afford an invertible Faradaic reaction activity between target ions and the active material.…”

New green electrode materials derived from waste cigarette butts for capacitive deionization

“…Therefore, one of the most effective research angles is to seek better electrode materials (Anderson et al 2010;Zhao et al 2020). High specific surface area (SSA), favorable pore size distribution, high stability, and high conductivity are the key factors to consider ( Jia & Zhang 2016;Gao et al 2021;Li et al 2021).Carbon materials such as activated carbon (Ghaffour et al 2013;Asquith et al 2015), carbon nanotubes (Zhou et al 2018), carbon nanofibers (Wang et al 2012), graphene (Dong et al 2014), metal-organic framework-derived carbon materials (Ma et al 2019), and carbon aerogels (Liu et al 2020) have been widely studied. Most of these materials are energy-intensive and synthesized from expensive resources so high-performance electrode materials based on wastes or recycled products with abundant resources should be developed.…”